Patrizia MESSI - personale UniMoRe

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Patrizia MESSI

Professore Associato
Dipartimento di Scienze della Vita sede ex-Scienze Biomediche

Pubblicazioni

- UN NUOVO PROBIOTICO LATTOBACILLARE E SUE SPECIFICHE FORMULAZIONI PER USO UMANO "Composizioni nutraceutiche per il potenziamento dell’attività di principi lattobacillari” [Brevetto]
Bondi, Moreno; Messi, Patrizia; G., Frigerio; V., Gatti; D. I., Marchioretto
abstract

L'invenzione riguarda preparazioni di tipo dietetico-alimentare (nutraceutiche) basate sulla presenza di un lattobacillo sporigeno particolarmente stabile e dotato di elevate capacità di produrre acido lattico (L+) (il Bacillus coagulans o Lactobacillus sporogenes) nelle quali la capacità proliferativa della forma vegetativa risulta notevolmente esaltata dalla aggiunta dell’aminoacido “lisina” al mezzo di cultura, a differenza di quanto avviene con altri nutriliti aminoacidici che hanno un effetto stimolante decisamente inferiore o, addirittura, nullo.In particolare, l'invenzione descrive varie possibili composizioni dieto-nutraceutiche in cui il principio attivo Lactobacillus sporogenes risulta essere abbinato all’aminoacido “lisina” sia in forma di associazione tradizionale che in forma di supporto di crescita nel terreno di cultura; quest’ultima preparazione biologica, denominata LAB LYS98, è depositata con la sigla DSM 12316. Si descrivono possibili formulazioni tecnico-farmaceutiche idonee per consentire l’ingestione del preparato biologico e possibili applicazioni cliniche di tali preparazioni.

2024 - Cell-Free Supernatant from a Strain of Bacillus siamensis Isolated from the Skin Showed a Broad Spectrum of Antimicrobial Activity [Articolo su rivista]
Pedretti, Natalia; Iseppi, Ramona; Condò, Carla; Spaggiari, Luca; Messi, Patrizia; Pericolini, Eva; DI CERBO, Alessandro; Ardizzoni, Andrea; Sabia, Carla
abstract

In recent years, the search for new compounds with antibacterial activity has drastically increased due to the spread of antibiotic-resistant microorganisms. In this study, we analyzed Cell-Free Supernatant (CFS) from Bacillus siamensis, assessing its potential antimicrobial activity against some of the main pathogenic microorganisms of human interest. To achieve this goal, we exploited the natural antagonism of skin-colonizing bacteria and their ability to produce compounds with antimicrobial activity. Biochemical and molecular methods were used to identify 247 strains isolated from the skin. Among these, we found that CFS from a strain of Bacillus siamensis (that we named CPAY1) showed significant antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Streptococcus agalactiae, and Candida spp. In this study, we gathered information on CFS’s antimicrobial activity and on its sensitivity to chemical–physical parameters. Time–kill studies were performed; anti-biofilm activity, antibiotic resistance, and plasmid presence were also investigated. The antimicrobial compounds included in the CFS showed resistance to the proteolytic enzymes and were heat stable. The production of antimicrobial compounds started after 4 h of culture (20 AU/mL). CPAY1 CFS showed antimicrobial activity after 7 h of bacteria co-culture. The anti-biofilm activity of the CPAY1 CFS against all the tested strains was also remarkable. B. siamensis CPAY1 did not reveal the presence of a plasmid and showed susceptibility to all the antibiotics tested.

2024 - Characterization of virulence factors and antimicrobial resistance in Staphylococcus spp. isolated from clinical samples [Articolo su rivista]
Pedretti, Natalia; Iseppi, Ramona; Condò, Carla; Ghazanfa, Shakira; Messi, Patrizia; DI CERBO, Alessandro; Sabia, Carla
abstract

The virulence factors, antibiotic resistance patterns, and the associated genetic elements have been investigated in Staphylococcus species. A total of 100 strains has been isolated from clinical samples in the Microbiology Laboratory of Hesperia Hospital, Modena, Italy, and identified as Staphylococcus aureus (65), Staphylococcus epidermidis (24), Staphylococcus hominis (3), Staphylococcus saprophyticus (3), and Staphylococcus warneri (5). All the strains were analyzed to determine phenotypic and genotypic characters, notably the virulence factors, the antibiotics susceptibility, and the genetic determinants. The highest percentage of resistance in Staphylococcus spp. was found for erythromycin and benzylpenicillin (87% and 85%, respectively). All S. aureus, two S. epidermidis (8.3%), and one S. saprophyticus (33.3%) strains were resistant to oxacillin. The methicillin resistance gene (mecA) was detected by polymerase chain reaction (PCR) amplification in 65 S. aureus strains and in 3 coagulase-negative staphylococci (CoNS) (8.6%). With regard to the virulence characteristics, all the S. aureus were positive to all virulence tests, except for slime test. Among the CoNS isolates, 19 (79.1%) S. epidermidis and one (33.3%) S. saprophyticus strains resulted positive for the slime test only. The results obtained are useful for a more in-depth understanding of the function and contribution of S. aureus and CoNS antibiotic resistance and virulence factors to staphylococcal infections. In particular, the production of slime is very important for CoNS, a virulence fac- tor frequently found in infections caused by these strains. Further investigations on the genetic relatedness among strains of different sources will be useful for epidemiological and monitoring purposes and will enable us to develop new strategies to counteract the diffusion of methicillin-resistant S. aureus (MRSA) and CoNS strains not only in clinical field, but also in other related environments.

2024 - Efficacy and Synergistic Potential of Cinnamon (Cinnamomum zeylanicum) and Clove (Syzygium aromaticum L. Merr. & Perry) Essential Oils to Control Food-Borne Pathogens in Fresh-Cut Fruits [Articolo su rivista]
Iseppi, Ramona; Truzzi, Eleonora; Sabia, Carla; Messi, Patrizia
abstract

The presence of microbial pathogens in ready-to-eat produce represents a serious health problem. The antibacterial activity of cinnamon (Cinnamomum zeylanicum) and clove (Syzygium aromaticum L. Merr. & Perry) essential oils (EOs) was determined toward food-borne pathogens by agar disk diffusion and minimum inhibitory concentration (MIC) assays. The growth kinetics of all strains, both in a buffer suspension assay and “on food” in artificially contaminated samples, were also investigated. The two EOs demonstrated a good antibacterial effect both alone and in combination (EO/EO). The use of EO/EO led to a synergistic antibacterial effect, also confirmed by the growth kinetics studies, where the EOs were active after 10 h of incubation (p < 0.0001) at significantly lower concentrations than those when alone. In the “on food” studies performed on artificially contaminated fruit samples stored at 4 °C for 8 days, the greatest killing activity was observed at the end of the trial (8 days) with a reduction of up to 7 log CFU/g compared to the control. These results confirm the good antibacterial activity of the EOs, which were more effective when used in combination. Data from the "on food" studies suggest cinnamon and clove essential oils, traditionally used in the food industry, as a possible natural alternative to chemical additives. Keywords: cinnamon and clove essential oils; synergistic activity; food-borne pathogens; fresh-cut fruit; bio-preservation

2023 - Effects of Melaleuca alternifolia Chell (Tea Tree) and Eucalyptus globulus Labill. Essential Oils on Antibiotic-Resistant Bacterial Biofilms [Articolo su rivista]
Iseppi, Ramona; Mariani, Martina; Benvenuti, Stefania; Truzzi, Eleonora; Messi, Patrizia
abstract

2023 - Essential Oils and Bacteriocin-Based Active Edible Coating: An Innovative, Natural and Sustainable Approach for the Control of Listeria monocytogenes in Seafoods [Articolo su rivista]
Iseppi, Ramona; Camellini, Stefania; Zurlini, Chiara; Cigognini, Ilaria Maria; Cannavacciuolo, Mariarosaria; Messi, Patrizia
abstract

The anti-Listeria monocytogenes activity of four essential oils (EOs) (Salvia officinalis, Citrus limon, Mentha piperita and Thymus vulgaris) and bacteriocin bacLP17, added alone or in mixture in active edible coatings, was determined in artificially contaminated shrimps. The minimal inhibitory concentration (MIC) values of the EOs were determined against the NCTC 10888 strain of L. monocytogenes by using the broth microdilution method. The checkerboard method was carried out in tryptic soy broth (TSB), using microdilution to obtain the Fractional Inhibitory Concentration Index (FIC-Index) for six associations of EOs, chosen based on the best MIC results. All the EOs confirmed their anti-Listeria activity, both “in vitro” and inside the coatings. The coating matrix was suitable for use in the food field, allowing a gradual release of the EOs in packaged food. When the EOs were used in association (EO/EO) they were demonstrated to act synergistically, leading to a significant reduction in the amount (10–20 times) of EOs needing to be used, and consequently a decrease in the strong smell on the food. This effect was also confirmed when the compounds were incorporated into the coatings. The inclusion of the EOs within the coating not only ensured the anti-Listeria activity by increasing the shelf-life of food products, but also further mitigated the strong smell of the EOs, improving the organoleptic impact on the food and its sensory properties. Keywords: Listeria monocytogenes; shrimp; essential oils; bacteriocin; edible coating.

2023 - Lichens as a Natural Source of Compounds Active on Microorganisms of Human Health Interest [Articolo su rivista]
Condò, Carla; Anfelli, Igor; Forti, Luca; Sabia, Carla; Messi, Patrizia; Iseppi, Ramona
abstract

The antimicrobial properties of two lichen extracts (LC1 and LC2 solutions extracted in acetone and cyclohexane, respectively) were investigated against both Gram-positive and Gram-negative microorganisms through the agar well diffusion assay. Results displayed that both samples were similarly effective against all the indicator strains. The antimicrobial activity was maintained up to 30 days against Candida albicans ATCC 10231 with an inhibition zone of 38 mm and 37 mm for the LC1 and LC2 solutions extracted, respectively. In order to separate the single chemical components and to associate them with the biological activity, the two extracts were subjected to an activity-guided fractionation followed by a liquid chromatography mass spectrometry (LC–MS) Ion Trap 6310A for the chemical characterization. Chromatogram analysis of each sample that maintained an antimicrobial activity revealed the presence of a significant peak, at a retention time (tR) of 10.8 min, corresponding to a scabrosin derivative that could likely be associated with the antimicrobial activity. Results obtained in the present investigation, especially against the opportunistic pathogen C. albicans, are encouraging and could represent a preliminary step to a future solution toward a microorganism responsible for fungal infections, mainly occurring in immunocompromised patients and recently caused by drug-resistant strains.

2023 - Ozone treatments: environmentally friendly and effective techniques for sanitation of seedborne pathogens on maize and corn salad [Abstract in Atti di Convegno]
Cafasso, M.; Cortiello, M.; Modica, F.; Messi, P.; Stefani, E.; Giovanardi, D.
abstract

2023 - Special Issue: State-of-Art of Microbial Concerns in Food Safety [Articolo su rivista]
Iseppi, Ramona; Messi, Patrizia
abstract

2023 - Synergistic Inhibition of Methicillin-Resistant Staphylococcus aureus (MRSA) by Melaleuca alternifolia Chell (Tea Tree) and Eucalyptus globulus Labill. Essential Oils in Association with Oxacillin [Articolo su rivista]
Iseppi, Ramona; Condò, Carla; Messi, Patrizia
abstract

The presence of antibiotic-resistant bacteria has become a major therapeutic priority. This trend indicates the need for alternative agents to antibiotics, such as natural compounds of plant origin. By assessing membrane permeability, we investigated the antimicrobial activity of Melaleuca alternifolia and Eucalyptus globulus essential oils (EOs) against three strains of methicillin-resistant Staphylococcus aureus (MRSA). Using the checkerboard method, the efficacy of single EOs, in association with each other or in combination with oxacillin, was quantified by calculating the fractional inhibitory concentrations (FIC Index). All EOs showed a reduction in bacterial load, an alteration of membrane permeability which leads to an increase in its function, resulting in the release of nucleic acids and proteins. The treatment with EO–oxacillin combinations and associated EO–EO resulted in a synergistic effect in most of the tests performed. EO–EO association showed a high activity in the alteration of the membrane, increasing the permeability to about 80% in all the MRSA strains treated. In conclusion, the combination of EOs and antibiotics represents a valid therapeutic support against MRSA bacteria, allowing for a decrease in the antibiotic concentration needed for therapeutic use.

2022 - Eco-Friendly Edible Packaging Systems Based on Live-Lactobacillus kefiri MM5 for the Control of Listeria monocytogenes in Fresh Vegetables [Articolo su rivista]
Iseppi, Ramona; Zurlini, Chiara; Cigognini, Ilaria Maria; Cannavacciuolo, Mariarosaria; Sabia, Carla; Messi, Patrizia
abstract

2021 - Antifungal Activity and DNA Topoisomerase Inhibition of Hydrolysable Tannins from Punica granatum L. [Articolo su rivista]
Brighenti, V.; Iseppi, R.; Pinzi, L.; Mincuzzi, A.; Ippolito, A.; Messi, P.; Sanzani, S. M.; Rastelli, G.; Pellati, F.
abstract

Punica granatum L. (pomegranate) fruit is known to be an important source of bioactive phenolic compounds belonging to hydrolysable tannins. Pomegranate extracts have shown antifungal activity, but the compounds responsible for this activity and their mechanism/s of action have not been completely elucidated up to now. The aim of the present study was the investigation of the inhibition ability of a selection of pomegranate phenolic compounds (i.e., punicalagin, punicalin, ellagic acid, gallic acid) on both plant and human fungal pathogens. In addition, the biological target of punicalagin was identified here for the first time. The antifungal activity of pomegranate phenolics was evaluated by means of Agar Disk Diffusion Assay and minimum inhibitory concentration (MIC) evaluation. A chemoinformatic analysis predicted for the first time topoisomerases I and II as potential biological targets of punicalagin, and this prediction was confirmed by in vitro inhibition assays. Concerning phytopathogens, all the tested compounds were effective, often similarly to the fungicide imazalil at the label dose. Particularly, punicalagin showed the lowest MIC for Alternaria alternata and Botrytis cinerea, whereas punicalin was the most active compound in terms of growth control extent. As for human pathogens, punicalagin was the most active compound among the tested ones against Candida albicans reference strains, as well as against the clinically isolates. UHPLC coupled with HRMS indicated that C. albicans, similarly to the phytopathogen Coniella granati, is able to hydrolyze both punicalagin and punicalin as a response to the fungal attack. Punicalagin showed a strong inhibitory activity, with IC50 values of 9.0 and 4.6 µM against C. albicans topoisomerases I and II, respectively. Altogether, the results provide evidence that punicalagin is a valuable candidate to be further exploited as an antifungal agent in particular against human fungal infections.

2021 - Essential Oils: A Natural Weapon against Antibiotic-Resistant Bacteria Responsible for Nosocomial Infections [Articolo su rivista]
Iseppi, Ramona; Mariani, Martina; Condò, Carla; Sabia, Carla; Messi, Patrizia
abstract

Abstract: The emergence of antibiotic-resistant bacteria has become a major concern worldwide. This trend indicates the need for alternative agents to antibiotics, such as natural compounds of plant origin. Using agar disc diffusion and minimum inhibitory concentration (MIC) assays, we investigated the antimicrobial activity of Citrus aurantium (AEO), Citrus x limon (LEO), Eucalyptus globulus (EEO), Melaleuca alternifolia (TTO), and Cupressus sempervirens (CEO) essential oils (EOs) against three representatives of antibiotic-resistant pathogens and respective biofilms: vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum - lactamase (ESBL)-producing Escherichia coli. Using the checkerboard method, the efficacy of the EOs alone, in an association with each other, or in combination with the reference antibiotics was quantified by calculating fractional inhibitory concentrations (FICs). All the EOs displayed antibacterial activity against all strains to different extents, and TTO was the most effective. The results of the EO–EO associations and EO–antibiotic combinations clearly showed a synergistic outcome in most tests. Lastly, the effectiveness of EOs both alone and in association or combination against biofilm formed by the antibiotic-resistant strains was comparable to, and sometimes better than, that of the reference antibiotics. In conclusion, the combination of EOs and antibiotics represents a promising therapeutic strategy against antibiotic-resistant bacteria, even protected inside biofilms, which can allow decreasing the concentrations of antibiotics used.

2021 - Plant extracts for the control of listeria monocytogenes in meat products [Articolo su rivista]
de Niederhausern, S.; Bondi, M.; Camellini, S.; Sabia, C.; Messi, P.; Iseppi, R.
abstract

The antimicrobial activity of garlic (Allium sativum L.) and onion (Allium cepa L.) plant active extracts was determined against Listeria monocytogenes in two meat products. Samples of sausages “cacciatore” and cooked ham in vacuum-packaged slices were artificially contaminated, and the presence of Listeria was evaluated during the sausages ripening and throughout the shelf-life of the cooked ham. The test carried out on sausages did not show differences among treated and untreated samples. The antagonistic activity of the plant extracts against the pathogen was probably hidden by the competition from the sausages microbial flora and the pH and the water activity (aw) decrease. On the other hand, the plant extracts determined an initial reduction of about 1.00 log cfu/g of the L. monocytogenes viable count in the cooked ham slices contaminated with 103 cfu/g, but the best result was obtained with the contamination of 102 cfu/g of L. monocytogenes. In addition to the pathogen’s initial decrease, we observed an extension of the lag phase and a reduction of the Listeria growth rate. Considering that the presence of L. monocytogenes during the slicing phase of the cooked ham does not exceed 10 cfu/g, the use of plant extracts can lead to complete pathogen elimination.

2021 - Ready-to-eat sandwiches as source of pathogens endowed with antibiotic resistance and other virulence factors [Articolo su rivista]
Camellini, S.; Iseppi, R.; Condo', C.; Messi, P.
abstract

The aim of this study was to evaluate and characterize the bacterial load present in twenty-four Ready-To-Eat (RTE) sandwiches, purchased at refrigerated vending machines and supermarkets in the province of Modena (Italy). We isolated 54 bacterial strains, including pathogens of interest in food safety, such as Listeria, Staphylococcus, Enterococcus, Yersinia, Aeromonas and Acinetobacter spp. Phenotypic tests have been performed on these pathogens to detect the presence of virulence factors, such as gelatinase production and hemolytic capability. To test their antibiotic resistance features, the minimum inhibitory concentration (MIC) against eight commonly used antibiotics (Amikacin, Ciprofloxacin, Ampicillin, Oxacillin, Imipenem, Tetracycline, Erythromycin and Vancomycin) was also evaluated. The results showed that among the 54 isolates, fifty percent (50%) belonged to harmless microorganisms (Leuconostoc and Lactococcus), whereas the remaining fifty percent (50%) included pathogenic bacteria (Listeria ivanovii, Listeria monocytogenes, Staphylococcus aureus, Yersinia, and Citrobacter spp.), species responsible for pathologies often difficult to treat due to the presence of antibiotic resistance features. This study demonstrates the importance of thorough controls, both during the production and marketing of RTE food like sandwiches, to avoid reaching the infectious load and the onset of pathologies, particularly dangerous for old and immunocompromised patients.

2020 - Antibiotic Resistance and Virulence Traits in Vancomycin-Resistant Enterococci (VRE) and Extended-Spectrum β-Lactamase/AmpCproducing(ESBL/AmpC) Enterobacteriaceaefrom Humans and Pets [Articolo su rivista]
Iseppi, Ramona; DI CERBO, Alessandro; Messi, Patrizia; Sabia, Carla
abstract

Background: We investigated the virulence factors, genes, antibiotic resistance patterns, and genotypes (VRE and ESBL/AmpC) production in Enterococci and Enterobacteriaceae strains isolated from fecal samples of humans, dogs, and cats. Methods: A total of 100 fecal samples from 50 humans, 25 dogs, and 25 cats were used in the study. MICs of nine antimicrobials were determined using the broth microdilution method. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (VRE and ESBL/AmpC) and virulence genes both in Enterococcus species, such as cytolysin (cylA, cylB, cylM), aggregation substance (agg), gelatinase (gelE), enterococcal surface protein (esp), cell wall adhesins (efaAfs and efaAfm), and in Enterobacteriaceae, such as cytolysin (hemolysin) and gelatinase production (afa, cdt, cnf1, hlyA, iutA, papC, sfa). Results: Enterococcus faecium was the most prevalent species in humans and cats, whereas Enterococcus faecalis was the species isolated in the remaining samples. A total of 200 Enterobacteriaceae strains were also detected, mainly from humans, and Escherichia coli was the most frequently isolated species in all types of samples. In the Enterococcus spp, the highest percentages of resistance for ampicillin, amoxicillin/clavulanate, erythromycin, tetracycline, ciprofloxacin, teicoplanin, and vancomycin were detected in cat isolates (41.6%, 52.8%, 38.9%, 23.6%, 62.5%, 20.8%, and 23.6% respectively), and in E. coli, a higher rate of resistance to cefotaxime and ceftazidime emerged in cat and dog samples, if compared with humans (75.4% and 66.0%, 80.0% and 71.4%, and 32.0% and 27.2%, respectively). Regarding the total number of enterococci, 5% and 3.4% of the strains were vancomycin and teicoplanin resistant, and the vancomycin resistance (van A) gene has been detected in all samples by PCR amplification. All the Enterobacteriaceae strains were confirmed as ESBL producers by PCR and sequencing, and the most frequent ESBL genes in E. coli strains from humans and pet samples were blaCTX-M-1 and blaCTX-M-15. Conclusions: Our results provide evidence that one or more virulence factors were present in both genera, underlining again the ability of pet strains to act as pathogens

2020 - Antilisterial Activity of Bacteriocins Produced by Lactic Bacteria Isolated from Dairy Products [Articolo su rivista]
De Niederhausern, Simona; Camellini, Stefania; Sabia, Carla; Iseppi, Ramona; Bondi, Moreno; Messi, Patrizia
abstract

Sixty-nine Lactic Acid Bacteria (LAB) and bifidobacteria were isolated and identified from Italian dairy products (raw milk, cream, butter, soft cheese and yoghurt) to find new antimicrobial compounds to use as food bio-preservatives. All the isolates were preliminarily screened by the deferred antagonism method for bacteriocin production. Afterwards, to evaluate the release of bacteriocin in liquid medium, the Cell-Free Supernatant Fluid (CFSF) of the best producers was tested by agar well diusion assay. The study allowed the selection of three bacteriocin producing strains (Enterococcus faecium E23, Bifidobacterium thermophilum B23 and Lactobacillus bulgaricus L21), endowed with the strongest and broadest inhibitory capability against the pathogen Listeria monocytogenes. The molecular characteristics and the chemical–physical properties of both producers and the respective bacteriocins were studied and compared. The results showed that E. faecium E23 was the best producer strain and its class IIa bacteriocins, called enterocin E23, exhibited a good spectrum of activity towards L. monocytogenes. Enterocin E23 was stable over a wide range of pH and at low temperatures for at least four months and, for this reason, it can be employed in refrigerated foods for the control of L. monocytogenes, the major concern in dairy products.

2020 - Antimicrobial activity of spices essential oils and its effectiveness on mature biofilms of human pathogens [Articolo su rivista]
Condò, Carla; Anacarso, Immacolata; Sabia, Carla; Iseppi, Ramona; Anfelli, Igor; Forti, Luca; de Niederhäusern, Simona; Bondi, Moreno; Messi, Patrizia
abstract

The antibacterial activity of Pimpinella anisum L., Cinnamomum zeylanicum, Syzygium aromaticum, and Cuminum cyminum L. essential oils (EOs) against some common pathogenic microorganisms (Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 14990, Enterococcus faecalis ATCC 29212, Streptococcus pyogenes ATCC 1915, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 27853, Aeromonas hydrophila ATCC 7966, Proteus mirabilis ATCC 10005, Klebsiella pneumoniae ATCC 13883, and Candida albicans ATCC 10231) and their biofilms was studied. The EOs inhibitory effects were evaluated by both Agar Well Diffusion assay and Minimum Inhibitory Concentration (MIC) determination. The most active EOs, cinnamon and cloves, were also tested on 18, 24, 48, 72 hours mature biofilms. Cinnamon and cloves exhibited the best results showing a significant activity against all the tested bacteria. Concerning biofilm, results suggest that Cinnamomum zeylanicum oil may be a useful approach to impair the biofilm produced by the tested Gram-negative bacteria.

2020 - Combined antimicrobial use of essential oils and bacteriocin bacLP17 as seafood biopreservative to control Listeria monocytogenes both in planktonic and in sessile forms [Articolo su rivista]
Iseppi, R.; Camellini, S.; Sabia, C.; Messi, P.
abstract

The antilisterial activity of Thymus vulgaris, Salvia officinalis essential oils (EOs) and bacteriocin bacLP17 (previously isolated from seafood) was determined, using the compounds alone and in combination. The Disk Diffusion, Minimal Inhibitory Concentration (MIC) and Agar Well Diffusion assays were used to evaluate the effectiveness of the compounds against 12 Listeria monocytogenes in planktonic form, whereas the anti-Listeria biofilm activity was determined against the same strains in optical density (O.D.) at 570 nm, with crystal violet staining method. The lowest MIC values resulted for T. vulgaris EO and bacLp17 (0.5 μl/ml and 2 μl/ml, respectively). The combinations with the best results, expressed as FIC-Index, were T. vulgaris/S. officinalis EOs and EOs/bacLp17. The anti-biofilm activity of single EOs and bacLP17 was similar, whereas the combined use of the two kinds of EOs led to a synergistic activity. Lastly, the best anti-biofilm effect was observed with the combination bacLP17/S. officinalis and bacLP17/T. vulgaris, compared to both control and the single use of the EOs. The present study suggests that the combination of natural compounds such as T. vulgaris, S. officinalis EOs and bacLp17 may be a useful approach to the control of planktonic and sessile cells of L. monocytogenes in seafood products.

2020 - Controversial Aspects Displayed by Enterococci: Probiotics or Pathogens? [Articolo su rivista]
Bondi, M.; Laukova, A.; De Niederhausern, S.; Messi, P.; Papadopoulou, C.; Economou, V.
abstract

For centuries, selected Enterococci, facultative anaerobic, nonspore-forming Gram-positive bacteria belonging to the Lactic Acid Bacteria (LAB), have been widely used in the production of a variety of fermented and nonfermented food products ranging from dairy and meat products to vegetable and sea foods. Enterococci have also properties that are of technological interest in the food industry, and some strains have been used as probiotics for the maintenance of normal intestinal microbiota, stimulation of the immune system, and improvement of the nutritional value of foods and feeds in humans and animals However, following the emergence of antibiotic-resistant (AMR) enterococci and particularly of the vancomycin-resistant enterococci (VRE), these microorganisms have turned from generally recognized as safe (GRAS) for human consumption to significant pathogens threatening human health and thriving in the hospital environment. Thus, recently the trend of using enterococci as probiotics for human consumption is in debate due to the controversial aspects of these bacteria which appear to be “friends and foes”

2020 - Evaluation of Bacterial Biofilm Removal Properties of MEDSTER 2000 Cold Sterilant on Different Materials [Capitolo/Saggio]
Iseppi, Ramona; Feminò, Raimondo; Sabia, Carla; Messi, Patrizia
abstract

We studied the antibacterial and anti-biofilm properties of MEDSTER 2000, a pH neutral biodegradable mixed acidic peroxide disinfectant belonging to the class IIb medical device which has been designed for decontamination and cold sterilization of hospital instruments. The broth microdilution method was used to define the antibacterial activity against planktonic form of both classified bacteria and antibiotic resistant strains of clinical source, whereas effectiveness toward their biofilm was determined on mature biofilm, grown both on plastic and stainless steel surfaces. The results showed that for the planktonic form the antibacterial activity of MEDSTER 2000 was already observed after 10 min at the lowest concentration (0.1%), and this effect was not exposure-and/or concentration-dependent. After the same time of exposure at the concentration of 2% the disinfectant was able to completely eradicate all tested bacteria grown in sessile form on both surfaces, with a greater than 6 log CFU/cm2 reduction in viable cells. This result is supported by the microscope observation by crystal violet and live/dead assays. For the high antibacterial and anti-biofilm ability emerged, MEDSTER 2000 could represent a new and more effective approach for semicritical devices that need a high-level disinfection and could not sustain the process of heat sterilization.

2020 - In Vitro Activity of Essential Oils Against Planktonic and Biofilm Cells of Extended-Spectrum β-Lactamase (ESBL)/Carbapenamase-Producing Gram-Negative Bacteria Involved in Human Nosocomial Infections [Articolo su rivista]
Iseppi, Ramona; DI CERBO, Alessandro; Aloisi, Piero; Manelli, Mattia; Pellesi, Veronica; Provenzano, Cinzia; Camellini, Stefania; Messi, Patrizia; Sabia, Carla
abstract

The aim of this study was to analyze the antibacterial activity of four essential oils (EOs), Melaleuca alternifolia, Eucalyptus globulus, Mentha piperita, and Thymus vulgaris, in preventing the development and spread of extended-spectrum -lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa and carbapenemase (KPC)-producing Klebsiella pneumoniae. A total of 60 strains were obtained from the stock collection from the Microbiology Laboratory of Hesperia Hospital, Modena, Italy. Twenty ESBLproducing E. coli, 5 K. pneumoniae, 13 KPC-producing K. pneumoniae, and 20 MBL-producing P. aeruginosa were cultured and reconfirmed as ESBL and carbapenamase producers. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (ESBL and KPC/MBL). Antibacterial activity of the EOs was determined using the agar disk diusion assay, and minimal inhibitory concentrations (MICs) were also evaluated. Lastly, adhesion capability and biofilm formation on polystyrene and glass surfaces were studied in 24 randomly selected strains. M. alternifolia and T. vulgaris EOs showed the best antibacterial activity against all tested strains and, as revealed by agar disk diusion assay, M. alternifolia was the most eective, even at low concentrations. This eect was also confirmed by MICs, with values ranging from 0.5 to 16 g/mL and from 1 to 16 g/mL, for M. alternifolia and T. vulgaris EOs, respectively. The EOs’ antibacterial activity compared to antibiotics confirmed M. alternifolia EO as the best antibacterial agent. T. vulgaris EO also showed a good antibacterial activity with MICs lower than both reference antibiotics. Lastly, a significant anti-biofilm activity was observed for the two EOs (*P < 0.05 and **P < 0.01 for M. alternifolia and T. vulgaris EOs, respectively). A good antibacterial and anti-biofilm activity of M. alternifolia and T. vulgaris EOs against all selected strains was observed, thus demonstrating a future possible use of these EOs to treat infections caused by ESBL/carbapenemase-producing strains, even in association with antibiotics.

2020 - Keyboard Contamination in Intensive Care Unit: Is Cleaning Enough? Prospective Research of In Situ Effectiveness of a Tea Tree Oil (KTEO) Film [Capitolo/Saggio]
Melegari, Gabriele; Iseppi, Ramona; Mariani, Martina; Giuliani, Enrico; Caciagli, Valeria; Bertellini, Elisabetta; Messi, Patrizia; Barbieri, Alberto
abstract

After the SARS-CoV-2 pandemic, disinfection practices and microbial load reduction have become even more important and rigorous. To determine the contamination of keyboard surface and the relative risk to transfer healthcare-associated pathogens to susceptible patients, as it frequently happens in Intensive Care Unit (ICU), a standard keyboard (SK), a cleanable keyless keyboard (KK) with smooth surface and a standard keyboard coated with a 3M Tegaderm film added with active essential oil (tea tree oil) (KTEO) were tested. S. aureus, including MRSA strains, were detected in ICU, with values ranging from 15% to 57%. Gram negative strains belonging to the Enterobacteriaceae family were also found with values ranging from 14% to 71%. Similar Gram positive and Gram negative strains were found on all surfaces, but with low percentage, and only environmental bacteria were detected using the settling plates method. The Microbial Challenge Test performed on KTEO showed high rates of decrease for all the pathogens with statistical significance both at 24 and 48h (p=0.003* and p=0.040*, respectively). Our results suggest that the use of KTEO may be a feasible strategy for reducing the transmission of pathogens in health care setting and may be complementary to surface cleaning protocols.

2020 - Phytochemical Composition and In Vitro Antimicrobial Activity of Essential Oils from the Lamiaceae Family against Streptococcus agalactiae and Candida albicans Biofilms [Articolo su rivista]
Iseppi, Ramona; Tardugno, Roberta; Brighenti, Virginia; Benvenuti, Stefania; Sabia, Carla; Pellati, Federica; Messi, Patrizia
abstract

Abstract: The antimicrobial activity of different essential oils (EOs) from the Lamiaceae family was evaluated on Streptococcus agalactiae, Candida albicans, and lactobacilli. S. agalactiae is the main cause of severe neonatal infections, such as sepsis, meningitis, and pneumonia. C. albicans is a primary causative agent of vulvovaginal candidiasis, a multifactorial infectious disease of the lower female reproductive tract. Lactobacilli represent the dominant bacterial species of the vaginal flora and constitute the natural defense against pathogens. On the basis of the preliminary results, the attention was focused on the EOs from Lavandula x intermedia Emeric ex Loisel. and Mentha arvensis L. By using gas chromatography (GS) retention data and mass spectra, it was possible to identify more than 90% of the total composition of the EO samples. The minimal inhibitory concentration (MIC) and anti-biofilm activity of the two EOs were determined against all isolated strains, using the EOs by themselves or in combination with each other and with drugs (erythromycin and fluconazole). The results showed a good antimicrobial and anti-biofilm activity of both EOs and a synergistic effect, leading to the best results against all the strains, resulted using the combinations EOs/EOs and antimicrobials/EOs.

2020 - Virulence Factors, Drug Resistance and Biofilm Formation in Pseudomonas Species Isolated from Healthcare Water Systems [Articolo su rivista]
Iseppi, R.; Sabia, C.; Bondi, M.; Mariani, M.; Messi, P.
abstract

Pseudomonas aeruginosa is a frequent causative agent of healthcare-associated diseases, but recently, other members of the Pseudomonas genus have been recognized to cause human colonization and infection. Since the aquatic environment could be an important source of contamination, we studied the drug resistance and virulence profiles in Pseudomonas species isolated from healthcare water systems. 17 Pseudomonas spp. out of 57 were randomly selected and their drug resistance and virulence profiles were later evaluated. Based on the positivity to the tests, the adhesion capability and biofilm formation on polystyrene and glass surfaces were studied in 6 strains, each belonging to different species. Six Pseudomonas strains (35%) were α-hemolytic, nine (53%) showed a positivity to the gelatinase test, and P. acidovorans 2R only was capable to degrade DNA. All Pseudomonas strains presented urease activity and the production of siderophores was widely observed (64,7%). Most of the strains showed one of the three types of motilities, 15 Pseudomonas (88.23%) resulted bacteriocin producers and all strains were resistant to one or more antibiotics. Lastly, among the six selected strains, P. aeruginosa 98.5 and P. fluorescens 97.4 were the best biofilm producers. Our study has highlighted how the majority of isolates shows biological characteristics that contribute to the pathogenicity of Pseudomonas. These features emphasize the virulence potentiality of other members of the Pseudomonas genus besides Pseudomonas aeruginosa, making them potentially pathogenic, especially against immunocompromised individuals.

2019 - Antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils and their combination against food-borne pathogens and spoilage bacteria in ready-to-eat vegetables [Articolo su rivista]
Iseppi, Ramona; Sabia, Carla; de Niederhäusern, Simona; Pellati, Federica; Benvenuti, Stefania; Tardugno, Roberta; Bondi, Moreno; Messi, Patrizia
abstract

The antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils (EOs), and their combination against food-borne and spoilage bacteria (Listeria monocytogenes, Salmonella enteritidis, Yersinia enterocolitica, Escherichia coli and Pseudomonas spp.) was determined. The EOs inhibitory effect was evaluated both in vitro by using the disk diffusion assay and the minimum inhibitory concentration (MIC) determination, and on food by using an artificially contaminated ready-to-eat (RTE) vegetables. The results showed that the lowest MIC values were obtained with R. officinalis and T. vulgaris EOs against E. coli (4 and 8 μL/mL, respectively). The incorporation of the EOs alone or their combination in RTE vegetables reduced the viable counts of all the tested strains. Lastly, in the on food study we simulated the worst hygienic conditions, obtaining results that can be considered a warranty of safety.

2019 - Bacteriocin activity of Lactobacillus brevis and Lactobacillus paracasei ssp. paracasei [Articolo su rivista]
Iseppi, Ramona; Messi, Patrizia; Camellini, Stefania; Sabia, Carla
abstract

Methodology. Biochemical and molecular methods were used to identify 100 lactobacilli isolated from rectal swabs. Among these, L. paracasei ssp. paracasei LP5 and L. brevis LP9 showed significant antibacterial activity against S. agalactiae and L. monocytogenes. Accordingly, characterization of their bacteriocins, BacLP5 and BacLP9, was conducted to obtain information on their kinetic production, sensitivity to chemico-physical parameters and molecular weight. To investigate the possible use of the two Lactobacillus strains as probiotics, their gastrointestinal resistance, cellular adhesiveness and sensitivity to antibiotics were also studied. Results. The obtained data show that BacLP5 and BacLP9 most likely belong to class II bacteriocins and both have a molecular weight of approximately 3 kDa. The production of BacLP5 and BacLP9 started after 4 h (40 and 80 AU ml−1), respectively. Both of the Lactobacillus strains survived gastric and intestinal juices well and showed adhesive capability on HEp-2 cells. Conclusion. Due to their peculiar antimicrobial characteristics, L. paracasei ssp. paracasei LP5 and L. brevis LP9 are suitable for use in the treatment of vaginal disorders, through both oral and transvaginal administration

2019 - Characterization of Anti-Listeria monocytogenes Properties of two Bacteriocin-Producing Enterococcus mundtii Isolated from Fresh Fish and Seafood [Articolo su rivista]
Iseppi, R.; Stefani, S.; de Niederhausern, S.; Bondi, M.; Sabia, C.; Messi, P.
abstract

This study addressed the bacteriocin production in 116 lactic acid bacteria isolated from 143 fish and seafood samples. The screening for the production of antibacterial substances allowed for the selection of 16 LAB isolates endowed with inhibitory capability. Bacteriocins (bacLP17 and bacLP18) of two strains, Enterococcus mundtii LP17 and Enterococcus mundtii LP18, respectively, isolated from red mullet and sardine samples, determined large inhibition zones against all the Listeria species. Virulence traits and antibiotic resistances of all producers were verified, and no isolates presented dangerous characteristics, including the two best bacteriocin producers E. mundtii LP17 and E. mundtii LP18, which were subsequently investigated for their potential use in fish and seafood products biopreservation. For both strains, the highest level of bacteriocin production (1280 AU/ml) was recorded when cells were grown at 30 °C in MRS broth at pH ranging from 6.0 to 9.0, and high levels of adsorption of bacteriocins, bacLP17 and bacLP18, to the target cells Listeria monocytogenes were also observed. The results obtained in this study revealed that two strains of E. mundtii originating from seafood exhibited a strong inhibitory activity against L. monocytogenes and may be useful in controlling the growth of this pathogen in the same food products.

2019 - Chemical characterization and evaluation of the antibacterial activity of essential oils from fibre-type cannabis sativa L. (Hemp) [Articolo su rivista]
Iseppi, R.; Brighenti, V.; Licata, M.; Lambertini, A.; Sabia, C.; Messi, P.; Pellati, F.; Benvenuti, S.
abstract

Volatile terpenes represent the largest group of Cannabis sativa L. components and they are responsible for its aromatic properties. Even if many studies on C. sativa have been focused on cannabinoids, which are terpenophenolics, little research has been carried out on its volatile terpenic compounds. In the light of all the above, the present work was aimed at the chemical characterization of seventeen essential oils from different fibre-type varieties of C. sativa (industrial hemp or hemp) by means of GC-MS and GC-FID techniques. In total, 71 compounds were identified, and the semi-quantitative analysis revealed that α- and β-pinene, β-myrcene and β-caryophyllene are the major components in all the essential oils analysed. In addition, a GC-MS method was developed here for the first time, and it was applied to quantify cannabinoids in the essential oils. The antibacterial activity of hemp essential oils against some pathogenic and spoilage microorganisms isolated from food and food processing environment was also determined. The inhibitory effects of the essential oils were evaluated by both the agar well diffusion assay and the minimum inhibitory concentration (MIC) evaluation. By using the agar diffusion method and considering the zone of inhibition, it was possible to preliminarily verify the inhibitory activity on most of the examined strains. The results showed a good antibacterial activity of six hemp essential oils against the Gram-positive bacteria, thus suggesting that hemp essential oil can inhibit or reduce bacterial proliferation and it can be a valid support to reduce microorganism contamination, especially in the food processing field.

2019 - In vitro evaluation of the amoebicidal activity of rosemary (Rosmarinus officinalis L.) and cloves (Syzygium aromaticum L. Merr. & Perry) essential oils against Acanthamoeba polyphaga trophozoites [Articolo su rivista]
Anacarso, Immacolata; Sabia, Carla; de Niederhäusern, Simona; Iseppi, Ramona; Condò, Carla; Bondi, Moreno; Messi, Patrizia
abstract

Several species of the genus Acanthamoeba cause human diseases. Treatment of infections involves various problems, emphasising the need to develop alternative antiprotozoal agents. We studied the anti-amoebic activity of Essential Oils (EOs), derived from rosemary (Rosmarinus officinalis L.) and cloves (Syzygium aromaticum L. Merr. & Perry), against Acanthamoeba polyphaga strain. The amoebicidal activity of cloves and rosemary EOs was preliminary demonstrated by the morphology change (modifications in the cell shape, the presence of precipitates in the cytoplasm, autophagic vesicles, membrane blends) of the treated trophozoites. The cell-counts, carried out after staining trophozoites with a Trypan blue solution, revealed that both EOs were active in a dose-dependent manner and in relation to the exposure time. This activity was evident after few hours, with encouraging results obtained in particular with cloves EO, able to act at the lower concentrations and after 1Â h, probably for its high eugenol content (65.30%).

2018 - Effectiveness of polimeric coated films containing bacteriocin-producer living bacteria for Listeria monocytogenes control under simulated cold chain break [Articolo su rivista]
Degli Esposti, M.; Toselli, M.; Sabia, C.; Messi, P.; de Niederhäusern, S.; Bondi, M.; Iseppi, R.
abstract

Nisin, enterocin 416K1 and living bacteriocin-producer Enterococcus casseliflavus IM 416K1 have been entrapped in polyvinyl alcohol (PVOH) based coatings applied to poly (ethylene terephthalate) (PET) films, and their effectiveness in the control of the growth of Listeria monocytogenes ATCC 19117 has been tested. The anti-listerial activity of the doped coated films was evaluated by both a modified agar diffusion assay and a direct contact with artificially contaminated precooked chicken fillets stored at 4 °C, 22 °C and under simulated cold chain break conditions (1 day at 30 °C). The live-Enterococcus-doped film showed a more remarkable activity than nisin- and enterocin-doped films over long times both at 4 °C and 22 °C. The use of this film at 22 °C resulted in full inactivation of L. monocytogenes from the seventh day of the test. Live-Enterococcus-doped film displayed a much better antilisterial activity in comparison to nisin- and enterocin-doped films also in samples incubated at 4 °C, and submitted at one day (3rd or 7th day) of storage at 30 °C, to simulate cold chain break conditions. All results suggest that the live-Enterococcus-doped film can behave as a smart active food packaging, very effective in cold chain break conditions when the Listeria growth is fast.

2018 - Extended-Spectrum b-Lactamase, AmpC,and MBL-Producing Gram-Negative Bacteria on Fresh Vegetables and Ready-to-Eat Salads Sold in Local Markets [Articolo su rivista]
Iseppi, Ramona; DE NIEDERHAUSERN, Simona; Bondi, Moreno; Messi, Patrizia; Sabia, Carla
abstract

We investigated the occurrence of extended-spectrum b-lactamase (ESBL), AmpC, and carbapenemase- producing Gram-negative bacteria isolated from 160 samples of fresh vegetables (n =80) and ready-to-eat (RTE) prepacked salads (n =80). Phenotypic and genotypic analyses were carried out on the isolates in terms of the species present and relative resistance. Resistance to b-lactam antibiotics was found in only 44 (24 from fresh vegetables and 20 from RTE salads) of a total of 312 Gram-negative strains (14.1%). The prevalence of ESBL-producing strains from fresh vegetables was 83.3% (20/24) and 16.7% (4/24) for AmpC. Among the 20 bacterial isolates from RTE salads, 80% (16/20) were identiﬁed as ESBL-producing strains and the remaining 20% (4/20) as MBL-producing strains. PCR and sequencing conﬁrmed the presence of blaSHV-12, blaCTX-M-1, blaCTX-M-15, blaRHAN-1, blaACC-1, blaDHA-1, blaVIM-1, and blaIMP-1. Seven different replicons were identiﬁed, where IncHI1, FIA, and I1 were the most representative types; when compared with the Inc types, isolates from fresh vegetables and RTE salads were similar. The location of genes on a conjugative plasmid was conﬁrmed by positive results obtained with conjugation assays. Our study has demonstrated the occurrence and distribution of ESBL/AmpC and MBL strains in fresh vegetables and RTE salads in Italy and possible public health risks associated with consumption of these fresh products.

2018 - LATTOBACILLI CON ATTIVITÀ ANTIMICROBICA [Brevetto]
Sabia, Carla; Iseppi, Ramona; Messi, Patrizia
abstract

The invention relates to two strains of Lattobacilli (Lactobacillus paracasei ssp, paracasei LP5 and Lactobacillus brevis LP9) probiotics with antimicrobial activity, both against Listeria monocytogenes and Streptococcus agalactiae, and their use, alone or in combination, in particular as probiotics, and for the prevention of infections in fetus and / or in newborn in pregnant woman.

2018 - the probiotic edible film [Brevetto]
Anacarso, Imacolata; Pino, Elisa; Messi, Patrizia
abstract

Viene descritta la formulazione per la messa a punto di un film edibile antibatterico, utilizzabile come packaging alimentare, contenente al suo interno un ceppo probiotico capace di crescere e proliferare e contestualmente produrre la propria batteriocina. Le batteriocine sono molecole proteiche prodotte da alcuni batteri come metaboliti secondari con una spiccata attività antimicrobica nei confronti di altri ceppi batterici generalmente correlati al ceppo produttore; è comunque noto di batteriocine con uno spettro d’azione elevato, capaci di inibire batteri anche non strettamente correlati, appartenenti sia al gruppo dei Gram-positivi che dei Gram-negativi.

2017 - EXTENDED-SPECTRUM B-LACTAMASE AND PLASMID-MEDIATED AMPC GENES IN SWINE AND GROUND PORK [Articolo su rivista]
Sabia, Carla; Stefani, Sara; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Bondi, Moreno; Condo', Carla; Iseppi, Ramona; Anacarso, Immacolata
abstract

We investigated the presence of ESBL and AmpC-producing Enterobacteriaceae isolated from 200 rectal swabs of healthy swine and 200 samples of ground pork. Phenotypic testing by using the double synergy differential test (DSDT) for ESBL/ AmpC-positive strains was confirmed by PCR and DNA sequence analysis. The localization of beta-lactamase genes was established by conjugation experiments. ESBL and/or AmpC-producing Enterobacteriaceae was found in 52.2% (95/182) of the isolates collected from rectal swabs and 3% (3/100) of isolates obtained from ground pork samples. Polymerase chain reaction and sequencing confirmed the presence of blaTEM-20, blaTEM-34, blaTEM-52, blaCTX-M-1, blaSHV-12, blaTEM-11SHV-12, blaTEM-201SHV-12, blaCMY-2, blaTEM-11 CMY-2, blaACC-1 and blaACC-2. The conjugation assays yielded positive results, denoting a plasmid localization of the genes

2017 - Inhibition of Multidrug-Resistant Gram-Positive and Gram-Negative Bacteria by a Photoactivated Porphyrin [Articolo su rivista]
Bondi, M; Mazzini, A; De Niederhausern, S; Iseppi, R; Messi, P
abstract

The authors studied the in vitro antibacterial activity of the photo-activated porphyrin meso-tri(N-methyl-pyridyl), mono(N-tetradecyl-pyridyl)porphine (C14) against four multidrug-resistant bacteria: Staphylococcus aureus, Enterococcus faecalis (Gram-positive), Escherichia coli, Pseudomonas aeruginosa (Gram-negative). Using 10 g/ml of porphyrin and 60 sec irradiation we observed the remarkable susceptibility of S. aureus and E. faecalis to treatment while, under the same conditions, E. coli and P. aeruginosa showed very low susceptibility. In a later stage, suspensions of Gram-negative bacteria were processed with EDTA before photo-activation, obtaining a significant decrease in viable counts. In view of the results, if the combination of low porphyrin concentrations and short irradiation times will be effective in vivo also, this approach could be a possible alternative to antibiotics, in particular against localized infections due to multidrug-resistant microorganisms.

2017 - Isolation of two lactobacilli, producers of two new bacteriocin-like substances (BLS) for potential food-preservative use [Articolo su rivista]
Anacarso, Immacolata; Gigli, Luca; Bondi, Moreno; DE NIEDERHAUSERN, Simona; Stefani, Sara; Condo', Carla; Messi, Patrizia
abstract

The fermentation of meat by lactic acid bacteria (LAB) is a traditional practice in many countries of Europe. LAB are already used for probiotic use and/or their bacteriocins can be used as a food preservative. 21 LABs were isolated from ham samples and identified by PCR; in particular, L. plantarum-GS16 and L. paraplantarum-GS54 were identified as the best bacteriocin-like substance (BLS) producers, active against spoilage and pathogenic bacteria, Gram negative included. In these strains, the presence of virulence factors, antibiotic and gastrointestinal resistance was investigated. The kinetics of growth and the BLS biosynthesis was also evaluated at different pH values. Finally, both bacteriocin substances were partially characterized and included in the IIa class of Klaenhammer; as a potential application, both BLSs can be successfully used as food preservatives.

2017 - Legionella pneumophila in health-care setting: sensitivity to biocidal treatments in mono- and multi-species biofilms [Articolo su rivista]
Messi, Patrizia; De Niederhausern, Simona; Anacarso, Immacolata; Iseppi, Ramona; Sabia, Carla; Bondi, Moreno
abstract

ABSTRACT There is now proof that some Legionella pneumophila outbreaks in health-care setting are related to the presence of biofilms, microbial consortium capable to induce partial resistance against many commonly used biocides. The aim of this study was to evaluate if the susceptibility of L. pneumophila to bronopol, chlorhexidine and silver ions can be affected by coexisting aquatic bacteria (Pseudomonas aeruginosa, Pseudomonas putida and Stenotrophomonas maltophilia) in sessile form. The results show that the sensitivity could be influenced by the presence of a mixed flora: the bacterial counts of L. pneumophila were reduced more effectively in multi-species than in mono-species biofilms.

2017 - Natural Preservatives to Improve Food Quality and Safety [Articolo su rivista]
Bondi, Moreno; Lauková, Andrea; de Niederhausern, Simona; Messi, Patrizia; Papadopoulou, Chrissanthy
abstract

Food products can be contaminated by a variety of pathogenic and spoilage microbiota, the former causing foodborne diseases and the latter causing significant economic losses for the food industry due to undesirable effects on the food properties. Chemical compounds added to foods as antioxidant agents are also of concern and their safety and impact on human health is under discussion. For this reason, current trends in food processing are focusing on the use of natural compounds, which are considered as safe alternatives and satisfy the consumer preferences for more “green foods”. Their prospective use in the food production has the potential to lead towards the production of safer and healthier foods, not excluding their contribution to a more efficient preservation of the environment, when chemicals will be replaced with natural substances.

2016 - Conjugation-Mediated Transfer of Antibiotic-Resistance Plasmids Between Enterobacteriaceae in the Digestive Tract of Blaberus craniifer (Blattodea: Blaberidae). [Articolo su rivista]
Anacarso, Immacolata; Iseppi, Ramona; Sabia, Carla; Messi, Patrizia; Condo', Carla; Bondi, Moreno; DE NIEDERHAUSERN, Simona
abstract

Cockroaches, insects of the order Blattodea, seem to play a crucial role in the possible conjugation-mediated genetic exchanges that occur among bacteria that harbor in the cockroach intestinal tract. The gut of these insects can be thought of as an effective in vivo model for the natural transfer of antimicrobial resistance plasmids among bacteria. In our study, we evaluated the conjugation-mediated horizontal transfer of resistance genes between Escherichia coli and other microorganisms of the same Enterobacteriaceae family within the intestinal tract of Blaberus craniifer Burmeister, 1838 (Blattodea: Blaberidae). Different in vivo mating experiments were performed using E. coli RP4 harboring the RP4 plasmid carrying ampicillin, kanamycin, and tetracycline resistance genes as the donor and E. coli K12 resistant to nalidixic acid or Salmonella enterica serovar Enteritidis IMM39 resistant to streptomycin as the recipients. The RP4 plasmid was successfully transferred to both recipients, producing E. coli K12-RP4 and S. Enteritidis IMM39-RP4 transconjugants. Conjugation frequencies in vivo were similar to those previously observed in vitro. The transfer of the RP4 plasmid in all transconjugants was confirmed by small-scale plasmid isolation and agar gel electrophoresis, suggesting that the intestinal tract of cockroaches is an effective in vivo model for natural gene transfer. Our results confirm that cockroaches allow for the exchange of antimicrobial resistance plasmids among bacteria and may represent a potential reservoir for the dissemination of antibiotic-resistant bacteria in different environments. These findings are particularly significant to human health in the context of health care settings such as hospitals.

2016 - Extended spectrum ß-lactamase and AmpC-producing Enterobacteriaceae in raw vegetables [Poster]
Sabia, Carla; Anacarso, Immacolata; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Bondi, Moreno; Iseppi, Ramona
abstract

Antibiotic resistance in bacteria is a global problem exacerbated by the dissemination of resistant bacteria via uncooked food, such as green leafy vegetables. The attribution of fresh produce to the overall community-associated exposure of humans to ESBL- or AmpC- producing. The aim of the current study was carried out to assess the of extended spectrum β-lactamase and AmpC type β-lactamase in Enterobacteriaceae isolated from fresh vegetables sold in the local markets of Modena town. Methods: A total of 80 samples comprising carrot, spring onion, tomatoes, arugula, chicory, endive and frisee salad were processed microbiologically to isolate Enterobacteriaceae. The vegetables were mostly obtained from supermarkets. Species identification and antimicrobial susceptibility testing were carried out using the Vitek 2 system and the AST-GN041 card (bioMérieux). Phenotypic testing by using the Double Synergy Differential Test (DSDT) for ESBL/AmpC-positive strains was confirmed by PCR and DNA sequence analysis. The localization of β-lactamase genes was established by conjugation experiments. Results: Overall, of the 160 analyzed strains ESBLs/AmpC were detected in 20 isolates (12,5%) for the double-disk synergy test. The major ESBL determinant was the CTX-M type (7,5% isolates) and two SHV (1,25%). DHA and ACC (2,5 % of isolates) were AmpC-β lactamases type. Additionally, we identified newly recognized ESBL blaRAHN-2 sequences from Rahnella aquatilis. The conjugation has demonstrated the transmissibility of this resistance determinant. Conclusion: In conclusion, we report a highter and a low prevalence of ESBL and AmpC β-lactamase determinants respectively mostly in arugula and frisee salad . Public health risks associated with exposure to ESBL- and AmpC-producing bacteria through consumption of uncooked fresh produce are diverse. They range from occasional ingestion of 3GC-resistant opportunistic pathogens which may result in difficult-to-treat infections, to frequent ingestion of relatively harmless ESBL producing environmental bacteria that may therewith constitute a continuously replenished intestinal reservoir facilitating dissemination of ESBL genes to (opportunistic) pathogens.

2016 - Extended spectrum ß-lactamase-andAmpC-producing Enterobacteriaceae on raw vegetables. [Poster]
Sabia, Carla; Anacarso, Immacolata; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Bondi, Moreno; Iseppi, Ramona
abstract

2015 - Antimicrobial activity of silver doped fabrics for the production of hospital uniforms [Articolo su rivista]
Condo', Carla; Messi, Patrizia; Anacarso, Immacolata; Sabia, Carla; Iseppi, Ramona; Bondi, Moreno; DE NIEDERHAUSERN, Simona
abstract

Among several alternatives to control hospital-acquired infections (HAIs), a strategy could be the use of hospital uniforms imbued with antimicrobial substances. For this purpose we evaluated the antibacterial activity of two different silver doped fabrics employed for the production of hospital uniforms. The study was conducted in two-step. In the first the antimicrobial activity was evaluated in vitro against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212. In the second, we tested the total viable counts detected from beginning to end of the work shift on experimental silver doped uniforms worn by doctors, nurses, allied health assistants in different hospital wards. The in vitro tests showed a remarkable antibacterial activity of both silver doped samples (>99.9% reduction within 4h of exposure for Gram-positive and within 24 h for Gram-negative bacteria). The experimental uniforms provided results only slightly in agreement with in vitro data. Even if the increase of total viable counts was somewhat lower for experimental uniforms than traditional ones, significant differences were not observed. Despite the results on the uniforms worn, the addition of silver in fabrics to make medical equipment (supplies) remains an interesting option for HAI control.

2015 - Antimicrobial resistance and virulence traits in Enterococcus strains isolated from dogs and cats [Articolo su rivista]
Iseppi, Ramona; Messi, Patrizia; Anacarso, Immacolata; Bondi, Moreno; Sabia, Carla; Condo', Carla; De Niederhausern, Simona
abstract

We investigated presence and prevalence of antibiotic-resistances and other biological characters in enterococci isolated from faeces of healthy dogs and cats because these microorganisms represent important human and veterinary pathogens/opportunists, and a significant burden for healthcare systems. In all samples (n=115) we detected enterococci, with a predominance of Enterococcus faecium (42; 36.5%) and Enterococcus faecalis (36; 31.3%) species, endowed with virulence traits and multidrug-resistance. The two predominant resistance patterns (erythromycin, tetracycline) were examined by polymerase chain reaction for tet and erm genes. Only tetM for tetracycline, and ermA and ermB for erythromycin were detected. PCR for gelatinase gene (gelE) was positive in 62.6% of isolates, but only 26.1% produce gelatinase suggesting the existence of silent genes. efaAfs and efaAfm genes were found in E. faecalis and E. faecium respectively. 89.6% of isolates produced bacteriocin-like substances with a prevailing action against Listeria genus and, among these, 33.9% were positive for the bacteriocin structural genes entA, entL50 or entP. According to our study, pet animals can be considered a reservoir of potentially pathogenic enterococci and we cannot exclude that those microorganisms may be responsible for opportunistic infections in high-risk pet owners

2015 - Prevalence of multi-drug-resistant (MDR) bacteria in air samples from indoor and outdoor environments [Articolo su rivista]
Messi, Patrizia; Sabia, Carla; Anacarso, Immacolata; Condo', Carla; Iseppi, Ramona; Stefani, Sara; DE NIEDERHAUSERN, Simona; Bondi, Moreno
abstract

The prevalence of multi-drug-resistant (MDR) bacteria in 48 air samples from indoor environments, surgical rooms, dental surgery and waste management plants has been investigated. A total of 280 bacterial strains belonging to different genera were isolated, and the operating rooms were the most contaminated ones (107 isolates), with all the isolates belonging to Gram-positive cocci (51.5 % Micrococcus spp., 48.5 % Staphylococcus spp.). Only 5 % of the isolates was sensitive to all the antibiotics tested, while the remaining strains resulted resistant to three (13 %), four (14 %), five (9 %) and six (10 %) antibiotics. Correlation between the resistance patterns and the environmental source of MDR bacteria isolates also emerged from the present investigation. This study confirms the high presence of antibiotic-resistant bacteria in air samples, finding that represents a threat for the possible transfer of resistance genes to pathogenic bacteria.

2014 - A bacteriocin-like substance produced from Lactobacillus pentosus 39 is a natural antagonist for the control of Aeromonas hydrophila and Listeria monocytogenes in fresh salmon fillets [Articolo su rivista]
Anacarso, Immacolata; Messi, Patrizia; Carla, Condò; Iseppi, Ramona; Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona
abstract

Here, we studied the ability of Lactobacillus pentosus 39, a BLS (Bacteriocin-like substance)-producing strain, to control the growth of Aeromonas hydrophila ATCC 14715 and Listeria monocytogenes ATCC 19117 artificially added to fresh salmon fillets at refrigeration temperatures and under simulated cold-chain break conditions. At refrigeration temperatures, Lb.pentosus 39 protective culture and its putative bacteriocin significantly reduced the A. hydrophila counts compared with the control (2.1 and 1.4 logCFU/g reductions, respectively). Similar behaviour was observed for L.monocytogenes (3.6 and 1.3 logCFU/g reductions, respectively). Under simulated cold-chain break conditions, an increase in temperature up to 30°C for 12h produced an evident increase in the development of A.hydrophila, L.monocytogenes, but also of Lb.pentosus 39, with a consequent increase in BLS production. Thus, this condition resulted in a greater reduction of both pathogens compared with samples stored at 4°C throughout the experiment (2.8 logCFU/g reduction for A.hydrophila and 5.8 logCFU/g reduction for L.monocytogenes). In samples treated with the putative bacteriocin alone, a less marked decrease was observed. Our study demonstrates the capability of Lb.pentosus 39 to control the growth of psychrotrophic bacteria in an experimental seafood model system. A similar biopreservation technology could provide more prolonged shelf life during storage of ready-to-eat seafood, ensuring safety, even under extreme conditions.

2014 - Amoebicidal Effects of Three Bacteriocin like Substances from Lactic Acid Bacteria against Acanthamoeba Polyphaga [Articolo su rivista]
Anacarso, Immacolata; Bondi, Moreno; Condo', Carla; DE NIEDERHAUSERN, Simona; Messi, Patrizia
abstract

We investigated the antiamoebic activity of three Bacteriocin Like Substances (BLS 39, BLS GS 54, BLS GS 16) produced by Lactic Acid Bacteria (LAB). The crude bacteriocins showed an amoebicidal effect against Acanthamoeba polyphaga, but with differences. BLS 39, produced by Lactobacillus pentosus, determined a prompt and progressive decrease of viable amoebal cell count, up to the end of the experiment (144 h), where the trophozoites were not detectable. A killing effect, but after a more prolonged contact time, was observed for BLS GS 54, produced by Lactobacillus paraplantarum, whereas the bacteriocin produced by Lactobacillus plantarum GS16 showed the lowest toxicity for A. polyphaga. For BLS GS 16 the maximum percentage of reduction in trophozoites count (45%) was obtained after 144 h, value much lower when compared to BLS GS54 and BLS 39, that showed values of 44,60% and 52,60% after only one hour of contact, with a maximum of 98% and 100% of non-viable cells, respectively, after 144 h. Morphological changes of the A. polyphaga cells as swollen cells, roundness and cellular lysis, were already observed after the first hours of contact with BLS and, at the end of the experiment, most of the cells were colored (blue), indicating their death. Currently there isn't evidence of BLS produced by LAB active against amoebas. In this study we have shown that all the three BLS secreted by the Lactic Acid Bacteria are endowed with amoebicidal effect against Acanthamoeba polyphaga, killing the protozoan with different effectiveness and at different times of contact.

2014 - Detection and partial characterization of a bacteriocin-like substance produced by Lactobacillus fermentum CS57 isolated from human vaginal secretions [Articolo su rivista]
Sabia, C.; Anacarso, I.; Bergonzini, A.; Gargiulo, R.; Sarti, M.; Condò, C.; Messi, P.; de Niederhausern, S.; Iseppi, R.; Bondi, M.
abstract

Lactobacilli (150) from human vaginal secretions were tested for the production of antimicrobial substances which can provide a physiological defense against the pathogenic microorganisms in the vaginal area. Sixteen of the isolates (10.6%) showed antibacterial activity against one or several closely related microorganisms used as indicators. Lactobacillus fermentum CS57 was the best producer and secretes a bacteriocin-like substance (BLS) with antagonistic activity against Streptococcus agalactiae and Candida albicans. The compound was susceptible to the proteolytic enzymes and was heat labile. The mode of action was identified as bactericidal. The crude activity of the L. fermentum CS57 BLS was linked to a substance with a molecular weight larger than 30 kDa. Plasmid analysis of L. fermentum CS57 revealed the presence of a plasmid band with molecular weight of 54.7 kb. All L. fermentum CS57 non-producer variants (BLS) obtained by curing experiments, showed loss of plasmid band and were susceptible to the BLS of the original strain. Therefore antimicrobial activity and immunity production seem to be linked to genes located on that same plasmid. Taking into account our results, L. fermentum CS57 could be considered a candidate for potential use as probiotic for the prophylaxis of vaginal human infections

2014 - Emerging microbial concerns in food safety and new control measures [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Halami, Prakash M; Papadopoulou, Chrissanthy; DE NIEDERHAUSERN, Simona
abstract

The editorial collects a brief summary of the topics discussed in the articles that are published in Emerging Microbial Concerns in Food Safety and New ControlMeasures. We hope that readers of this special issue will find some information of interest in order to expand their knowledge in this field and to increase their level of attention on matters here reported.

2014 - Prevalence and characterization of extended-spectrum beta-lactamase-producing Enterobacteriaceae in food-producing animals in Northern Italy [Articolo su rivista]
Stefani, Sara; Giovanelli, I; Anacarso, Immacolata; Condo', Carla; Messi, Patrizia; De Niederhausern, Simona; Bondi, Moreno; Iseppi, Ramona; Sabia, Carla
abstract

The aim of this study was to assess the production of extended spectrum beta-lactamases (ESBL) in 56 strains of Enterobacteriaceae, obtained from 100 rectal swabs of farm animals, and to evaluate the horizontal transfer capacity of the genetic determinants of resistance. The ESBL-positive strains were confirmed by phenotypic testing, confirmed by PCR and DNA sequence analysis. The localization of beta-lactamase genes was established by conjugation experiments. Of the 56 analyzed strains, 20 (36%) resulted positive for ESBL production by the double-disk synergy test, and belonged to Escherichia coli 15 (75%) and Klebsiella ozaenae 5 (25%) species. Molecular analysis showed that all ESBL-producing isolates possessed genes encoding for TEM-type enzymes and/or CTX-M. The conjugation assays yielded positive results, thus denoting a plasmidic localization of the genes. This study highlights the high percentage of ESBL-positive Enterobacteriaceae and the mobility of the responsible genes. Gene mobility implies highly negative consequences in terms of drug therapy because of the spread of antibiotic resistance.

2013 - Antibiotics and heavy metals resistance and other biological characters in enterococci isolated from surface water of Monte Cotugno Lake (Italy) [Articolo su rivista]
DE NIEDERHAUSERN, Simona; Bondi, Moreno; Anacarso, Immacolata; Iseppi, Ramona; Sabia, Carla; Bitonte, F.; Messi, Patrizia
abstract

Considering the limited knowledge about the biological characters in enterococci isolated from surface waters, we investigated antibiotic and heavy-metal resistance, bacteriocin production, and some important virulence traits of 165 enterococci collected in water samples from Monte Cotugno Lake, the largest artificial basin built with earth in Europe. The species distribution of isolates was as follows: Enterococcus faecium (80%), Enterococcus faecalis (12.7%), Enterococcus casseliflavus (3%), Enterococcus mundtii (1.8%), Enterococcus hirae (1.8%), Enterococcus durans (0.6%). All enterococci showed heavy metal resistance toward Cu, Ni, Pb and Zn, were susceptible to Ag and Hg, and at the same time exhibited in large percentage (83.7%) resistance to one or more of the antibiotics tested. Relatively to virulence factor genes, 50.9% enterococci were positive for gelatinase (gelE), 10.9% for aggregation substance (agg), 12.7% and 66.6% for the cell wall adhesins (efaAfs and efaAfm), respectively. No amplicons were detected after PCR for cytolysin production (cylA, cylB and cylM) and enterococcal surface protein (esp) genes. Bacteriocin production was found in most of the isolates. Given that the waters of the Monte Cotugno Lake are used for different purposes, among which farming and recreational activities, they can contribute to spread enterococci endowed with virulence factors, and antibiotics and heavy metals resistance to humans.

2013 - Antimicrobial Resistance and Other Related Virulence Factors in Staphylococcus Spp isolated from Food, Environmental and Humans in Italy [Articolo su rivista]
Anacarso, Immacolata; Condo', Carla; Sabia, Carla; Messi, Patrizia; Niederhausern, Simona de; Bondi, Moreno; Iseppi, Ramona
abstract

We investigated the presence of antibiotic-resistances and others important virulence factors in coagulase negative and positive staphylococci, isolated from several sources (food, environmental and clinical). Thirty-four staphylococci were isolated and identified (28 coagulase-positive were identified as Staphylococcus aureus, 6 remaining Coagulase Negative Staphylococci were identified as 3 S. epidermidis, 2 S. warneri, 1 S. hycus). All the strains were analyzed both with phenotypic and genotypic assays in order to evaluate the virulence factors and the susceptibility against antibiotics and to correlate them to the sources of isolation. Results showed that isn’t a direct correlation between features researched and isolation, and the different virulence factors are as widespread as antibiotic-resistance. The isolation from food of a strain of Staphylococcus aureus with a high methicillin resistance was very interesting. 15 of the 34 strains were found to possess multi-drug resistance and in 7 cases with Minimum Inhibitory Concentration(MIC) really very high; also in this case there is no distinction between the coagulase-positive and coagulase-negative staphylococci and their origin of isolation.

2013 - Biofilm formation, development and relevance [Capitolo/Saggio]
Messi, Patrizia
abstract

Bacteria are able to grow adhered to almost every surface, forming architecturally complex communities termed biofilms. Biofilms are multicellular communities held together by a self-produced extracellular matrix. Biofilm development is a dynamic process that occurs in different sequential phases and involves a series of steps. Biofilms impact humans in many ways as they can form in natural, medical, and industrial settings. For instance, formation of biofilms on medical devices, such as catheters or implants often results in difficult-to-treat chronic infections. Not all biofilms cause problems both in the clinical and environmental context. Within humans, bacterial biofilms may also play a protective role and promote a probiotic effect when consumed through various fermented foods. Also within the industrial context there are several successful examples of the positive use of beneficial biofilms. Recent data concerning biofilm formation, evolution, structure and functions are reported in this chapter. Particular emphasis is given to discussing the different adverse effects and beneficial aspects of biofilms.

2013 - Erratum: Protozoa and human macrophages infection by Legionella pneumophila environmental strains belonging to different serogroups (Archives of Microbiology DOI: 10.1007/s00203-012-0851-9) [Articolo su rivista]
Messi, P.; Bargellini, A.; Anacarso, I.; Marchesi, I.; Niederhausern, S. D.; Bondi, M.
abstract

2013 - Protozoa and human macrophages infection by Legionella pneumophila environmental strains belonging to different serogroups [Articolo su rivista]
Messi, Patrizia; Bargellini, Annalisa; Anacarso, Immacolata; Marchesi, Isabella; De Niederhausern, Simona; Bondi, Moreno
abstract

Three Legionella pneumophila strains isolated from municipal hot tap water during a multicentric Italian survey and belonging to serogroups 1, 6, 9 and the reference strain Philadelphia-1 were studied to determine the intracellular replication capability and the cytopathogenicity in human monocyte cell line U937 and in an Acanthamoeba polyphaga strain. Our results show that both serogroups 1 and Philadelphia-1 were able to multiply into macrophages inducing cytopathogenicity, while serogroup 6 and ever more serogroup 9 were less efficient in leading to death of the infected macrophages. Both serogroups 1 and 6 displayed a quite good capability of intracellular replication in A. polyphaga, although serogroup 1 was less cytopathogenic than serogroup 6. Serogroup 9, like Philadelphia-1 strain, showed a reduced efficiency of infection and replication and a low cytopathogenicity towards the protozoan. Our study suggests that bacterial pathogenesis is linked to the difference in the virulence expression of L. pneumophila serogroups in both hosts, as demonstrated by the fact that only L. pneumophila serogroup 1 shows the contextual expression of the two virulence traits. Serogroup 6 proves to be a good candidate as pathogen since it shows a good capacity for intracellular replication in protozoan.

2012 - Acanthamoeba polyphaga, a potential environmental vector for the transmission of food-borne and opportunistic pathogens [Articolo su rivista]
Anacarso, Immacolata; De Niederhausern, Simona; Messi, Patrizia; Guerrieri, Elisa; Iseppi, Ramona; Sabia, Carla; Bondi, Moreno
abstract

The endosymbiotic relationship could represent for many bacteria an important condition favouring their spread in the environment and in foods. For this purpose we studied the behaviour of some food-borne and opportunistic pathogens (Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Enteritidis, Aeromonas hydrophila, Yersinia enterocolitica) when internalized in Acanthamoeba polyphaga. Our results confirm the capability of the bacteria tested to grow within amoebal hosts. We can observe two types of interactions of the bacteria internalized in A. polyphaga. The first type, showed by Y. enterocolitica and A. hydrophila, was characterized by an early replication, probably followed by the killing and digestion of the bacteria. The second type, showed by E. faecalis and S. aureus was characterized by the persistence and grow inside the host without lysis. Lastly, when amoebae were co-cultured with L. monocytogenes and S. Enteritidis, an eclipse phase followed by an active intracellular growth was observed, suggesting a third type of predator-prey trend. The extracellular count in presence of A. polyphaga, as a result of an intracellular multiplication and subsequent release, was characterized by an increase of E. faecalis, S. aureus, L. monocytogenes and S. Enteritidis, and by a low or absent cell count for Y. enterocolitica and A. hydrophila. Our study suggests that the investigated food-borne and opportunistic pathogens are, in most cases, able to interact with A. polyphaga, to intracellularly replicate and, lastly, to be potentially spread in the environment, underlining the possible role of this protozoan in food contamination.

2011 - Anti-listerial activity of chitosan and Enterocin 416K1 in artificially contaminated RTE products [Articolo su rivista]
Anacarso, Immacolata; DE NIEDERHAUSERN, Simona; Iseppi, Ramona; Sabia, Carla; Bondi, Moreno; Messi, Patrizia
abstract

We investigated the anti-listerial activity of chitosan and Enterocin 416K1 alone or in association by threedifferent experiments performed (i) in agar well diffusion, (ii) in buffer suspensions assay, (iii) in RTEvegetables and fruit artificially contaminated with Listeria monocytogenes NCTC 10888. All testsdemonstrated the anti-listerial activity of the natural bioactives and the best action obtained by their usein combination. In the artificially contaminated vegetables (trial 1 zucchini, corn, radishes; trial 2 mixedsalad, carrots, zucchini) the inhibition of listeria was almost comparable, with the greatest killing activityobserved in samples added with both antibacterial substances. In the artificially contaminated fruits(trial 3 apples, grapes; trial 4 pineapple, melon) a more evident anti-listerial activity in samples treatedwith chitosaneenterocin in association also emerged. In particular, in trial 3 we obtained a total killing oflisteria within 72 h, while in trial 4 there was only a minimal inhibition, difference attributable to thecomposition of the two samples. Considering the results obtained, we can conclude that the use ofchitosan and Enterocin 416K1, alone or in combination, could be a feasible solution to extend the shelflife and to obtain the microbiological safety of ready-to-eat vegetable and fruits.

2011 - Anti-listerial activity of coatings entrapping living bacteria [Articolo su rivista]
Iseppi, Ramona; DE NIEDERHAUSERN, Simona; Anacarso, Immacolata; Messi, Patrizia; Sabia, Carla; Pilati, Francesco; Toselli, Moreno; Esposti, M. D.; Bondi, Moreno
abstract

Polyvinyl alcohol (PVOH) based coatings entrapping either living bacteriocin-producer Enterococcus casseliflavus IM 416K1 bacteria or Enterocin 416K1 have been prepared and applied to poly(ethylene terephthalate) (PET) films. The antimicrobial activity of coated PET films was evaluated against Listeria monocytogenes NCTC 10888 by qualitative agar diffusion assays and by direct contact with artificially contaminated food samples (würstel and seasoned cheese) stored at 4 °C and 22 °C. Anti-listerial activity of both coatings was observed for both tests. However, the live-enterococcus doped coatings showed a much more remarkable anti-listerial activity than enterocin doped ones. Interestingly, live-enterococcus doped coatings lead to a strong decrease of L. monocytogenes viable counts even at 22 °C, indicating that they are able to contrast efficiently the fast L. monocytogenes growth occurring at this temperature in würstel samples. In this respect, they can be considered smart coatings, being able to be responsive towards an accidental rise of temperature during food storage. The capability of bacteria to survive for a long time can also assure a long lasting antibacterial activity.

2011 - Ecological behaviour of three serogroups of Legionella pneumophila within a model plumbing system [Articolo su rivista]
Messi, Patrizia; Anacarso, Immacolata; Bargellini, Annalisa; Bondi, Moreno; Marchesi, Isabella; DE NIEDERHAUSERN, Simona; Borella, Paola
abstract

Three Legionella pneumophila strains isolated from water samples and belonging to serogroups (sgs) 1, 6, and 9 were analysed for their capability to colonise an experimental model simulating a domestic hot water distribution system. Ecological factors that could influence the persistence of sgs as intracellular life within protozoan hosts and bacterial interference by the production of antagonistic compounds were also studied. L. pneumophila viable counts incremented both in the planktonic and in the sessile phases. Serogroup 6 had a marked prevalence during the whole experiment and exhibited the highest host infection efficiency. Serogroup 1 was significantly less represented, but showed the highest capability to reproduce inside the protozoan hosts. Serogroup 9 was poorly isolated and less adapted to the intracellular life. Among 14 bacteria continuously isolated in the system, five (35.7%) produced antagonistic substances against legionella, with differences according to the bacterial strain and L. pneumophila serogroups.

2011 - Vancomycin-resistance Transferability from VanA Enterococci to Staphylococcus aureus. [Articolo su rivista]
DE NIEDERHAUSERN, Simona; Bondi, Moreno; Messi, Patrizia; Iseppi, Ramona; Sabia, Carla; Manicardi, Giuliano; Anacarso, Immacolata
abstract

In last decade methicillin-resistant Staphylococcus aureus with high level of vancomycin-resistance (VRSA) have been reported and generally the patients with VRSA infection were also infected with a vancomycin-resistant Enterococcus (VRE). Considering that the high level of vancomycin-resistance in VRSA isolates seems to involve the horizontal transfer of Tn1546 transposon containing vanA gene from coinfecting VRE strains, the authors have studied the "in vitro" conjugative transfer of this resistance from VanA enterococci to S. aureus. Out of 25 matings performed combining five vancomycin-resistant enterococci as donors (three Enterococcus faecalis and two Enterococcus faecium), and five S. aureus as recipients, all clinical isolates, two have been successful using E. faecalis as donor. The transfer of vancomycin-resistance was confirmed by vanA gene amplification in both transconjugants and the resistance was expressed at lower levels (MIC 32 μg/ml) in comparison with the respective VRE donors (MIC > 128 μg/ml). The vancomycin-resistance of trasconjugants was maintained even after subsequent overnight passages on MSA plates containing subinhibitory levels of vancomycin. This study shows that the vanA gene transfer can be achieved through techniques "in vitro" without the use of laboratory animals employed, in the only similar experiment previously carried out by other authors, as substrate for the trasconjugant growth. Moreover, in that previous experiment, contrary to this study, the vancomycin resistant S. aureus trasconjugants were selected on erythromycin agar and not by direct vancomycin agar selection.

2010 - Attività anti-listeria di Enterococcus casseliflavus 416K1batteriocino-produttore intrappolato in forma vivente incoating applicati a film di PET da impiegarsi nel campodell’active food packaging [Abstract in Rivista]
Messi, Patrizia; Iseppi, Ramona; DE NIEDERHAUSERN, Simona; Anacarso, Immacolata; Sabia, Carla; DEGLI ESPOSTI, Micaela; Toselli, Moreno; Pilati, Francesco; Bondi, Moreno
abstract

OBIETTIVI Il consumo di alimenti “ready-to-eat” e di prodotti refrigerati ha provocato un incremento di listeriosi e, poiché la refrigerazione è uno dei mezzi più efficaci di conservazione, la riconosciuta psicotrofia del patogeno ne rende il controllo estremamente difficoltoso. Una innovativa metodologia di “active food packaging” è stata da noi messa a punto incorporando nel materiale di confezionamento agenti microbici in grado di rallentare o inibire la proliferazione di L. monocytogenes. MATERIALI E METODI E’ stata valutata l’attività antilisteria di film polimerici (coating) contenenti una batteriocina purificata (Enterocina 416K1) e quella di film preparati inglobando lo stesso microrganismo produttore Enterococcus casseliflavus 416K1 in forma vitale. Tale attività è stata determinata qualitativamente “in vitro” e quantitativamente su campioni (formaggio e wurstel) artificialmente contaminati con L. monocytogenes NCTC10888. RISULTATIEntrambe le valutazioni hanno messo in evidenza l’attività antibatterica dei due tipi di coating nei confronti di L. monocytogenes NCTC10888. E’ stato possibile anche osservare nei coating allestiti con batteri vivi, la crescita di minicolonie di E. casseliflavus che in corrispondenza del loro sviluppo evidenziano attività antibatterica. CONCLUSIONI I risultati ottenuti dimostrano una buona attività antilisteria sia della batteriocina che del microrganismo stesso inglobato in forma vitale e che l’intrappolamento nei coating ibridi è sia compatibile col mantenimento della forma attiva della batteriocina che con la vitalità dei microrganismi. Il lavoro presentato è, a nostro avviso, una novità nel campo dell’active food packaging e in prospettiva potrà trovare un’utile applicazione nel campo della bioconservazione.

2010 - Influence of Legionella pneumophila and other water bacteria on the survival and growth of Acanthamoeba polyphaga. [Articolo su rivista]
Anacarso, Immacolata; E., Guerrieri; Bondi, Moreno; DE NIEDERHAUSERN, Simona; Iseppi, Ramona; Sabia, Carla; Contri, Miranda; Borella, Paola; Messi, Patrizia
abstract

We investigated in solid medium, in water microcosm co-cultures and by light and transmission electron microscopy the influence of Legionella pneumophila Lp-1, Pseudomonas aeruginosa ATCC 27853, Burkholderia cepacia ATCC 25416 and Pseudomonas fluorescens SSD35 on the growth and survival of Acanthamoeba polyphaga. The infection with L. pneumophila was microscopically characterized by the presence of few bacteria inside protozoa at 4th h, and by the beginning of disruptive effects in late phase of trial. In water microcosm studies, performed at different temperature, the more significant interactions were observed at 30°C. In these conditions, L. pneumophila caused a marked reduction in trophozoite and cyst counts from the 4th day until the end of incubation (11 days). B. cepacia showed, by microscopic observation, few and generally single rods within protozoan phagosomes and caused a light reduction of trophozoite viability and cyst formation in co-cultures. A more invasive type of endocytosis, characterized by an early invasion with the presence of a high bacteria number inside amoebae, was observed for Pseudomonas strains. P. fluorescens produced a violent lysis of the host, whereas P. aeruginosa did not cause lysis or suffering. These results underline that water bacteria other than legionella are capable of intracellular survival in Acanthamoeba, influencing the protozoa viable cycle.

2010 - Legionella pneumophila: ruolo dell’interferenza microbica nello sviluppo di biofilm “in vitro” e sensibilità ai biocidi [Abstract in Rivista]
Messi, Patrizia; Anacarso, Immacolata; DE NIEDERHAUSERN, Simona; Iseppi, Ramona; Bondi, Moreno
abstract

Obiettivi. La formazione e l'evoluzione di biofilm e la capacità di inserirsi in strutture microbiche preformate sono state studiate in un ceppo di Legionella pneumophila di sierogruppo 1 (Lp-1), osservando le eventuali modificazioni in presenza di batteri acquatici, anche in grado di produrre sostanze ad attività antibatterica (BLS), ed ospiti protozoari. Metodi. I ceppi allo studio sono stati coltivati in microhabitat idrici, singolarmente o in associazione, per verificare la capacità di aderire a superfici e formare biofilm. Risultati. Il miglior produttore di BLS, Pseudomonas fluorescens SSD ha mostrato il maggiore effetto negativo sulla sopravvivenza planctonica e sulla formazione di biofilm, mentre Pseudomonas aeruginosa ATCC 27853, in grado di inibire la crescita di Lp-1 in fase planctonica, non ne ha influenzato la formazione di biofilm. La contemporanea presenza di entrambe le specie di pseudomonas ha determinato un effetto sinergico negativo sulla formazione di biofilm, mentre Il ceppo non-produttore Acinetobacter lwoffii ATCC 15309 è stato l'unico che ha determinato il rafforzamento della struttura microbica formata da Lp-1. Per quanto riguarda la capacità di inserirsi in biofilm già strutturati, i nostri risultati hanno confermato che Lp-1 è in grado di aderire alle superfici e alle aggregazioni microbiche preformate, senza differenze particolari tra le diverse combinazioni, ad eccezione dei ceppi produttori P.fluorescens SSD e Aeromonas hydrophila. Le interazioni batteriche hanno influito anche sulla forza di adesione alle superfici del patogeno. Una sorta di equilibrio si è verificato infatti tra legionelle risospese e in forma sessile, con l'eccezione del biofilm costituito insieme a P. fluorescens SSD, in cui il rilascio del patogeno è risultato fortemente incrementato. Anche l’ospite protozoario si è dimostrato in grado di influenzare positivamente la formazione del biofilm di legionella, probabilmente a causa della capacità del patogeno di replicarsi all’interno dell'ameba, seguita dal rilascio della stessa in fase planctonica. Infine, i ceppi selezionati tra quelli che non avevano mostrato alcuna influenza diretta sulla sopravvivenza di Lp-1 sono stati impiegati per formare biofilm misti per studiare la sensibilità ai biocidi del patogeno all’interno di una comunità microbica. Conte batteriche più elevati sono state messe in evidenza nei biofilm formato solo da Lp-1 rispetto a quelli misti. Ciò potrebbe essere dovuto ad una minore adesione del patogeno quando co-coltivato con altri ceppi o ad una perdita di protezione che potrebbe verificarsi in un biofilm composto da germi sensibili. Conclusioni. I microrganismi acquatici, dotati di un notevole potenziale di adattamento e di una forte capacità di aderire alle superfici, si sono dimostrati in grado di influenzare gli altri batteri dalla comunità microbica con cui condividono lo stesso habitat naturale, come L. pneumophila. Migliorare le conoscenze sui biofilm associati alla legionella potrà consentire una scelta più mirata di disinfettanti da utilizzare per contrastare il persistere di L. pneumophila nell'ambiente.

2009 - Acanthamoeba, un “cavallo di Troia” per la sopravvivenza e diffusione ambientale di patogeni alimentari [Abstract in Rivista]
Anacarso, Immacolata; Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Iseppi, Ramona; Messi, Patrizia
abstract

Obiettivi specifici. Protozoi e batteri sono spesso coinvolti in complesse interazioni che giocano un ruolo importante nella diffusione ambientale di batteri patogeni e opportunisti, e di conseguenza possono rappresentare una minaccia per la salute umana. Numerosi studi hanno dimostrato che le FLA si nutrono per fagocitosi di cellule batteriche, tuttavia alcuni batteri possono evitare la lisi fagosomiale e instaurare una relazione simbiontica come ampiamente documentato per Legionella pneumophila e recentemente descritto per altri enterobionti Gram-negativi.Materiali e metodi. We studied the capability of the Gram negative Salmonella enteritidis, Aeromonas hydrophila, Yersinia enterocolitica and of the Gram-positive Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, all pathogens transmitted by food, to infect Acanthamoeba polyphaga in co-cultures. Ci è sembrato pertanto interessante condurre un’indagine sulla capacità infettante nei confronti di A. polyphaga di alcuni patogeni/opportunisti di interesse alimentare, dal momento che la capacità di comportarsi da parassita intracellulare, oltre a conferire al microrganismo un vantaggio ecologico ed influire sulla presenza nell’ambiente, potrebbe potenziarne la capacità invasiva nei confronti dell’ospite. A questo scopo sono state allestite co-colture in un rapporto tra numero di batteri e numero di amebe (Multiplicity Of Infection, MOI) pari a 10:1 che, ad intervalli di tempo stabiliti (0, 8, 24, 48, e 72 ore), sono state valutate per evidenziare l’ingresso e l’eventuale moltiplicazione batterica nell’ameba. Risultati. Dai nostri risultati è emerso che i batteri Gram-positivi testati non solo sopravvivono, ma si moltiplicano nel protozoo. Al contrario tra i batteri Gram-negativi solo S. enteritidis, dopo una iniziale “eclissi”, ha mostrato una notevole capacità replicativa che si è protratta fino alla fine della sperimentazione. Our results showed that Gram-positive bacteria not only survived, but multiplied in co-colture with A. polyphaga. E.faecalis and S.aureus were able to persist and grow intracellularly, without lytic attitude. Among the Gram-negative bacteria Y. enterocolitica and A. hydrophila, showed to replicate only in the early stages of the entry, but from 48th h onwards intracellular bacteria were undetectable. A more invasive behaviour has reported for L.monocytogenes and S. enteritidis. These last, that, after an initial "eclipse" until the 48th h, showed the ability to intracellularly replicate until the end of the study, with a significant increase in extracellular viable counts, due to a lytic activity or to the production and expulsion of small vesicles containing live bacteria. Conclusioni. Questo studio conferma la capacità di patogeni e opportunisti di parassitare ospiti amebici come già riportato per altri microrganismi responsabili di patologie infettive nell’uomo.

2009 - EFFICACIA DELLA MONOCLORAMMINA NELLA DISINFEZIONE DI IMPIANTI IDRICI PER IL CONTROLLO DI LEGIONELLA SPP E BIOFILM [Abstract in Rivista]
Messi, Patrizia; Anacarso, Immacolata; Bargellini, Annalisa; Marchesi, Isabella; Frezza, Giuseppina; Bondi, Moreno; Borella, Paola
abstract

Obiettivi specifici. Data la difficoltà di controllare la contaminazione da Legionella spp in sistemi idrici di grandi edifici, abbiamo ritenuto interessante valutare l’efficacia della monoclorammina, da tempo utilizzata negli USA per la disinfezione dell’acqua condottata, sulla persistenza del germe sia in forma planctonica che sessile in un impianto idrico ospedaliero contaminato da L. pneumophila.Materiali e metodi. Da marzo 2009 è stato installato un impianto a dosaggio controllato (4 mg/l) e continuo di monoclorammina sul sistema di distribuzione dell’acqua calda sanitaria di un edificio ospedaliero. A intervalli di tempo prestabiliti, sia prima che dopo l’installazione dell’impianto, sono stati effettuati prelievi di acqua e biofilm sui quali valutare la contaminazione da Legionella, la carica batterica totale e la presenza di amebe, utilizzando metodiche standardizzate.Risultati. I prelievi effettuati prima dell’utilizzo della monoclorammina hanno evidenziato una forte contaminazione dell’acqua (da 4,5 x 102 a 2,7 x 104 UFC/L secondo i punti di prelievo) con presenza di L. pneumophila sierogruppi 9, 6 e 1. Al termine della prima settimana di trattamento si è ottenuto un miglioramento solo parziale, con il 50% dei punti divenuti negativi; dopo un mese tutti i punti di prelievo, eccetto uno, si sono negativizzati e questo andamento si è confermato successivamente al terzo mese. Per quanto riguarda la carica batterica totale del biofilm, l’andamento è risultato analogo, con una diminuzione da 33.5 a 9,2 UFC/cm2 dopo un mese di trattamento; al termine del terzo mese i valori sono rimasti pressoché costanti (11,8 UFC/cm2). All’interno del biofilm, la concentrazione di legionelle è solo lievemente calata, passando da 4,2 x 102 prima del trattamento a 3,6 x 10 UFC/cm2 dopo tre mesi. La concentrazione di amebe nell’impianto idrico non ha subito variazioni, mantenendosi tra 1 e 10 cellule/ml in circolo e tra 10 e 100 cellule/ml nel biofilm, per tutta la durata della sperimentazione.Conclusioni. Il metodo proposto è risultato efficace nel mantenere sotto controllo la contaminazione da Legionella planctonica nel sistema. Pur essendo la monoclorammina attiva nel ridurre la carica microbica del biofilm, inclusa Legionella, la persistenza di amebe sia nel torrente idrico che nel biofilm sembra comunque favorire la sopravvivenza del patogeno anche in presenza del disinfettante. Sono in corso studi per comparare questo sistema di disinfezione con il biossido di cloro e stabilire se la monoclorammina è più efficace nel ridurre la formazione del biofilm e il rischio di corrosione delle tubature.

2009 - Interference of Lactobacillus plantarum strains in the in vitro conjugative transfer of R-plasmids. [Articolo su rivista]
Sabia, Carla; DE NIEDERHAUSERN, Simona; E., Guerrieri; Bondi, Moreno; Anacarso, Immacolata; Iseppi, Ramona; Messi, Patrizia
abstract

Probiotic compounds, which are often constituted of lactobacilli, exert a number of health benefits through maintenance of the intestinal ecosystem balance. Among the important interactions that occur in the gut microbiota, plasmid transfer by mating is an increasing cause of concern, particularly when antibiotic-resistant genes are involved. Because lactobacilli seem to be able to influence this mechanism, the aim of the present work was to investigate the in vitro capability of two Lactobacillus plantarum strains (one bacteriocin producer and one nonproducer) to interfere with the conjugation processes. For this purpose different matings were performed adding to the donor and recipient cells L. plantarum 35d bac+ and L. plantarum 396/1 bac- as agents of interference. Conjugations added with a Staphylococcus aureus strain or without any agent of interference were used as controls. The results of our experiments demonstrated that both lactobacillus strains were able to decrease mating frequency. Statistically significant differences in the viable transconjugants were obtained in the presence and in the absence of the lactobacilli. The effect was almost the same with the two L. plantarum independent of bacteriocin production. In the trial performed with S. aureus, no decrease in mating frequency was observed, confirming that the capability to interfere with R-plasmid transfer ability could be a property of the tested L. plantarum strains.

2009 - Use of Lactic Acid Bacteria (LAB) biofilms for the control of Listeria monocytogenes in a small-scale model [Articolo su rivista]
Guerrieri, Elisa; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Sabia, Carla; Iseppi, Ramona; Anacarso, Immacolata; Bondi, Moreno
abstract

The antilisterial activity in biofilms developed in a small-scale model by two LAB (lactic acid bacteria) bacteriocin producers (Lactobacillus plantarum 35d, Enterococcus casseliflavus IM 416K1) and by two non-producers (L. plantarum 396/1, Enterococcus faecalis JH2-2) was evaluated against Listeria monocytogenes NCTC 10888. The LAB biofilms showed the capability to influence the survival and the multiplication of the pathogen with differences among the strains. L. plantarum 35d displayed the highest efficacy reducing L. monocytogenes by 5.4 log in the planktonic population and by 3.9 log in the adherent population at the end of the experiment (10 days). L. plantarum 396/1 reduced L. monocytogenes by 3.8 log in the adherent cells and by 4.9 log in the planktonic cells and this outcome could be attributed to the pH reduction.The E. casseliflavus IM 416K1 biofilm caused a L. monocytogenes reduction of 3.7 log in the adherent cells and of 4.8 log in the planktonic cells and the role of the bacteriocin production seemed to be predominant as the pH values did not significantly decrease. This hypothesis is confirmed by a slight capability to influence the L. monocytogenes survival by the non-bacteriocinogenic E. faecalis JH2-2. Studies performed with L. monocytogenes in co-culture with a Pseudomonas putida strain, revealed a reduction of the antilisterial activity only for the biofilms produced by lactobacilli.

2008 - Anti-listerial activity of a polymeric film coated with hybrid coatings doped with Enterocin 416K1 for use as bioactive food packaging [Articolo su rivista]
Iseppi, Ramona; Pilati, Francesco; Marini, Michele; Toselli, Moreno; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Messi, Patrizia; Sabia, Carla; Manicardi, Giuliano; Anacarso, Immacolata; Bondi, Moreno
abstract

In this study, Enterocin 416K1, a bacteriocin produced by Enterococcus casseliflavus IM 416K1, was entrapped in an organic-inorganic hybrid coating applied to a LDPE (low-density polyethylene) film for its potential use in the active food packaging field. The antibacterial activity of the coated film was evaluated against Listeria monocytogenes NCTC 10888 by qualitative modified agar diffusion assay, quantitative determination in listeria saline solution suspension and direct contact with artificially contaminated food samples (frankfurters and fresh cheeses) stored at room and refrigeration temperatures. All investigations demonstrated that enterocin-activated coatings have a good anti-listeria activity. Qualitative tests showed a clear zone of inhibition in the indicator lawn in contact with and around the coated film. During the quantitative antibacterial evaluation the L. monocytogenes viable counts decreased to 1.5 log units compared to the control. The inhibitory capability was confirmed also in food-contact assays. In all food samples packed with coated films we observed a significant decrease in L. monocytogenes viable counts in the first 24 h compared to the control. This difference was generally maintained up to the seventh day and then decreased, with the exception of the cheese samples stored at refrigeration temperature.

2008 - Detection of bacteriocin production and virulence traits in vancomycin-resistant enterococci of different sources [Articolo su rivista]
Sabia, Carla; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Messi, Patrizia; Anacarso, Immacolata; Manicardi, Giuliano; Bondi, Moreno
abstract

Three hundred and two enterococci were isolated from food, animal and clinical samples in order to evaluate the incidence of vancomycin-resistant enterococci (VRE) and bacteriocin, cytolysin, haemolysin, gelatinase production.Among the isolates, 27 (8.9\%) were VRE, and 17 (63\%) of these showed, by the deferred antagonism method, bacteriocin production against gram-positive and some gram-negative indicators. Eight bacteriocin producers displayed by polymerase chain reaction an enterocin structural gene: six Enterococcus faecium the Enterocin A, two Enterococcus faecalis the Enterocin P genes. The enterocins AS-48, 31, L50 and 1071A/B genes were not found. Regarding the virulence factors, two VRE produced gelatinase and seven were haemolytic. Gelatinase gelE gene was found in 19 strains and cytolysin cylL(L) gene in eight. Among the strains showing the cylL(L) gene, only two E. faecalis expressed a beta-haemolysis.Our results showed the persistence of VRE in food, animal and clinical samples. Many of these strains displayed antibacterial activity and sometimes different components of virulence, which could emphasize their pathogenicity.This work indicates the need of a constant monitoring of enterococci in order to assess their possible pathogenic properties. The strains of interest in the food industry or used as probiotics should be tested for antibiotic resistance and virulence traits.

2008 - Effect of bacterial interference on biofilm development by Legionella pneumophila. [Articolo su rivista]
E., Guerrieri; Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Borella, Paola; Messi, Patrizia
abstract

In the ecology of Legionella pneumophila a crucial role may be played by its relationship with the natural flora; thus we investigated the interactions between Legionella and other aquatic bacteria, particularly within biofilms. Among 80 aquatic bacteria screened for the production of bacteriocin-like substances (BLSs), 66.2\% of them were active against L. pneumophila. The possible effect of some of these aquatic bacteria on the development and stability of L. pneumophila biofilms was studied. Pseudomonas fluorescens, the best BLS producer, showed the greatest negative effect on biofilm formation and strongly enhanced the detachment of Legionella. Pseudomonas aeruginosa, Burkholderia cepacia, Pseudomonas putida, Aeromonas hydrophila, and Stenotrophomonas maltophilia, although producing BLSs at different levels, were less active in the biofilm experiments. Acinetobacter lwoffii did not produce any antagonistic compound and was the only one able to strongly enhance L. pneumophila biofilm. Our results highlight that BLS production may contribute to determining the fate of L. pneumophila within ecological niches. The interactions observed in this study are important features of L. pneumophila ecology, which knowledge may lead to more effective measures to control the persistence of the germ in the environment.

2008 - Ruolo di Acanthamoeba polyphaga nella diffusione ambientale di patogeni di interesse alimentare [Abstract in Rivista]
Anacarso, Immacolata; Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Iseppi, Ramona; Guerrieri, Elisa; Messi, Patrizia
abstract

Protozoi e batteri sono spesso coinvolti in complesse interazioniche giocano un ruolo importante nella diffusione ambientale di batteripatogeni e opportunisti e di conseguenza per la salute umana.Numerosi studi hanno dimostrato che le amebe a vita libera si nutrono per fagocitosi di cellule batteriche. Tuttavia alcuni batteri possono evitare la lisi fagosomiale e instaurare una relazione simbiotica o parassitica, come ampiamente documentato per Legionella pneumophila e recentemente descritto per altri enterobionti Gram-negativi.Ci è sembrato pertanto interessante condurre un’indagine sullacapacità infettante nei confronti di Acanthamoeba polyphaga dialcuni patogeni e opportunisti di interesse alimentare dal momentoche la capacità di comportarsi da parassita intracellulare, oltre aconferire un vantaggio ecologico e influire sulla presenza nell’ambiente, potrebbe, anche in questo caso, potenziarne la capacità invasiva nei confronti dell’ospite. Co-culture dei batteri in esame con un ceppo di Acanthamoeba polyphaga di isolamento clinico sono state allestite in Page’s Amoebic Saline (PAS), incubate a 30°C e osservate per 48 ore. Ad intervalli regolari, sono state effettuate le conte dei batteri intracellulari, per evidenziare l’ingresso nell’ameba, ed extracellulari per rilevare, dal confronto col controllo senza ameba, l’eventuale moltiplicazione intracellulare. Dai nostri risultati è emerso che tutti i batteri Gram-positivi testati (E. faecalis, L. monocytogenes, S. aureus e uno Stafilococco Coagulasi Negativo)riuscivano non solo a sopravvivere ma anche a moltiplicarsi nell’ameba.Al contrario tra i batteri Gram-negativi testati (P. mirabilis,S. enteritidis, Y. enterocolitica ed E. coli) solo P. mirabilis è risultatoin grado di sopravvivere all’interno del protozoo, fino al terminedell’esperimento (48h) ma non di moltiplicarsi. Questo studio conferma la capacità di patogeni e opportunisti di interesse alimentare di parassitare ospiti amebici, come riportato per altri microrganismi responsabili di patologie infettive nell’uomo.

2007 - Influence of aquatic microorganisms on Legionella pneumophila survival [Articolo su rivista]
Guerrieri, Elisa; Bondi, Moreno; Borella, Paola; Messi, Patrizia
abstract

The ability of aquatic bacteria Pseudomonas fluorescens SSD (Ps-D) and Pseudomonas putida SSC (Ps-C) to support the persistence of Legionella pneumophila (Lp-1) in an artificial water microcosm was investigated for 42 day, at two different incubation temperatures. At 4 °C, individually suspended Lp-1 was no longer detectable just after 24 hours, while in co-cultures with Pseudomonas, Lp1 showed a better survival capability. At 30 °C, Lp-1 alone displayed high survival rates over the entire period of observation. When Lp-1 was inoculated with Ps-C and Ps-D, its count showed a marked decrease, followed by a gradual and costant decline.

2007 - SOPRAVVIVENZA E CRESCITA DI DIVERSI SIEROGRUPPI DI LEGIONELLA PNEUMOPHILA NELL’AMBIENTE ACQUATICO [Abstract in Rivista]
Marchesi, Isabella; Bargellini, Annalisa; Cauteruccio, Laura; Rivasi, Marianna; Guerrieri, Elisa; Messi, Patrizia; Borella, Paola
abstract

Obiettivo. Scopo dello studio era di verificare la capacità di sopravvivenza e crescita, in forma libera e nel biofilm, di ceppi di Legionella pneumophila appartenenti a diversi sierogruppi (sgs) in un sistema sperimentale che simula un impianto distribuzione di acqua calda.Materiali e metodi. Il modello da noi allestito è paragonabile a quello di un condominio di medie dimensioni, dove l’acqua a 40°C circola mediante una pompa. Dopo la stabilizzazione del sistema, sono stati inoculati 107 ufc/L ciascuno dei sgs 1, 6 e 9. I prelievi dell’acqua e del biofilm formato su un tubo posto all’interno della vasca sono stati effettuati settimanalmente per 3 mesi.Risultati. Dopo una settimana dall’inoculo, si è osservata una netta prevalenza del sg 6, pari al 70% sugli altri due ceppi. Tale trend si è confermato nel tempo e dopo sette settimane il sg 6 rappresentava il 93% degli isolati, contro un 7% del sg 1 e un valore prossimo allo 0% per il sg 9. Successivamente, l’andamento si è modificato, con un progressivo aumento del sg 1 che a 90 giorni rappresentava il 47% degli isolati contro il 41% del sg 6 e il 12% del sg 9. Andamenti del tutto analoghi sono stati osservati anche nei campioni di biofilm.Conclusioni. I risultati confermano che a parità di inoculo, ceppi appartenenti a diversi sierogruppi della specie L. pneumophila si diversificano sia nella formazione del biofilm che nella esistenza in forma planktonica. Tra i ceppi saggiati, l’adattabilità maggiore era del sg 6, seguita dai sgs 1 e 9. Va inoltre osservato che la percentuale del sg 1 (dal 7% al 47% delle legionelle isolate) sembra rispecchiare quella ritrovata in condizioni reali, sia nelle abitazioni che negli alberghi, a conferma della validità del nostro modello sperimentale per indagare sui meccanismi di crescita ambientale di Legionella spp.

2007 - Studio del parassitismo intracellulare di diversi sierogruppi di Legionella pneumophila nei confrontidi Acanthamoeba polyphaga [Abstract in Rivista]
Messi, Patrizia; Guerrieri, Elisa; Haskushi, E; DE NIEDERHAUSERN, Simona; Sabia, Carla; Bondi, Moreno; Borella, Paola
abstract

OBIETTIVO: Poiché il parassitismo costituisce un fattore chiave siaper l’ecologia che per la virulenza di L. pneumophila, abbiamo studiatoil comportamento di diversi sierogruppi in relazione a questoaspetto. MATERIALI E METODI:Tre ceppi di L. pneumophila di isolamentoidrico appartenenti ai sierogruppi 1, 6 e 9, e il ceppo di riferimentoL. pneumophila ATCC 33152 (Philadelphia-1) sono stati co-coltivaticon un ceppo di Acanthamoeba polyphaga per studiare invitro: (a) la cinetica di infezione (efficienza di ingesso nell’amebaa diversi tempi di infezione) e (b) la capacità di replicazione intracellularee la citopatogenicità nei confronti dell’ospite in un periodopost-infezione di 72 ore. RISULTATI: Il sierogruppo 1 ha mostrato la più rapida cinetica diinfezione e una sviluppata capacità di moltiplicazione all’internodell’ameba, pur consentendone una discreta conservazione. Diversoil comportamento del sierogruppo 6, che pur evidenziandouna buona capacità di replicazione intracellulare, ha mostratouna maggiore aggressività nei confronti dell’ospite, riducendone ilnumero e la vitalità. Il sierogruppo 9 è risultato meno adattato allavita intracellulare, denotando una ridotta efficienza di infezione edi replicazione ed una scarsa citopatogenicità. Philadelphia-1,nonostante appartenga al sierogruppo 1, era il meno efficientenell’infezione e nella replicazione e non ha influito sulla sopravvivenzadell’ameba. CONCLUSIONI: Le differenze emerse tra i ceppi allo studio risultanoparticolarmente interessanti in relazione alle potenzialità patogenedei sierogruppi a cui appartengono, dal momento che meccanismimolecolari simili presiedono la vita intracellulare nelleamebe e nei macrofagi. Il ceppo appartenente al sierogruppo 1,che è stato associato ad un caso clinico, ha infatti evidenziato unamaggiore specializzazione al parassitismo rispetto agli altri ceppiambientali. Il comportamento anomalo dimostrato dal ceppo diriferimento trova conferme solo parziali in letteratura e il fenomenoda cui è stato determinato rimane tuttora da definire.

2007 - VanA-type vancomycin-resistant enterococci in equine and swine rectal swabs and in human clinical samples. [Articolo su rivista]
DE NIEDERHAUSERN, Simona; Sabia, Carla; Messi, Patrizia; Guerrieri, Elisa; Manicardi, Giuliano; Bondi, Moreno
abstract

Vancomycin-resistant enterococci (VRE) in healthy people and in food-producing animals seems to be quite common in Europe. The existence of this community reservoir of VRE has been associated with the massive use of avoparcin in animal husbandry. Eight years after the avoparcin ban in Europe, we investigated the incidence of VanA enterococci, their resistance patterns, and the mobility of their glycopeptide-resistance determinants in a sampling of animal rectal swabs and clinical specimens. A total of 259 enterococci isolated from equine, swine, and clinical samples were subcultured on KF-streptococcus agar (Difco Laboratories, Detroit, MI) supplemented with vancomycin and teicoplanin; 7 (6.7\%), 10 (16\%), and 8 (8.6\%) respectively were found to be glycopeptides resistant (VanA phenotype). Slight differences in antimicrobial resistance patterns resulted among VRE recovered from the different sources. Polymerase chain reaction amplification demonstrated the presence of the vanA gene cluster and its extrachromosomal location in VRE plasmid DNA. VanA resistance was transferred in 7 out of 25 mating experiments, 4 with clinical, 2 with swine, and only 1 with equine donors. The conjugative plasmids of animal strains showed a high homology in the restriction profiles, unlike plasmids of clinical microrganisms. Our observations confirmed the possible horizontal transfer of VanA plasmids across different strains and, consequently, the diffusion of the vancomycin-resistance determinants.

2006 - Film polietilenici addizionati di Enterocina 416K1 da impiegare come active food packaging per il controllo di . [Abstract in Rivista]
Messi, Patrizia; Iseppi, Ramona; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Sabia, Carla; Anacarso, Immacolata; Marini, Michele; Pilati, Francesco; Bondi, Moreno
abstract

Obiettivi. Negli ultimi tempi ha destato un notevole interesse l’incorporazione di batteriocine e di altri antimicrobici di origine biologica nei materiali destinati al food-packaging,in particolare per contrastare lo sviluppo di Listeria monocytogenes. In questo studio è stata valutata la capacità antibatterica di film polimerici contenenti Enterocina 416K1, batteriocina prodotta da Enterococcus casseliflavus 416K1 e già studiata dal nostro gruppo di ricerca. Al fine di proporne un futuro utilizzo nell’ambito dell’active packaging, ne è stata inoltre saggiata la capacità inibente contro L. monocytogenes in matrici alimentari artificialmente contaminate.Materiali e metodi. L’attività antibatterica del coating polietilenico allestito con Enterocina416K1 nei confronti di L. monocytogenes NCTC 10888 è stata valutata impiegando tre metodiche: saggio in piastra con “agar diffusion” modificato (valutazione qualitativa), saggio per immersione in una sospensione del patogeno (valutazione quantitativa) e saggio su campioni alimentari (würstel e formaggio fresco) artificialmente contaminati, incubati a 4°C e 22°C per 28 giorni.Risultati. Le valutazioni qualitative e quantitative hanno dimostrato una notevole attività del coating nei confronti della listeria. Tale capacità è stata inoltre confermata nel saggio per contatto diretto: a 4°C le cariche di L. monocytogenes nei campioni confezionati col film antibatterico sono risultate inferiori di circa 1 log rispetto al controllo già dopo 24 ore di incubazione e fino al termine dell’esperimento. Anche a 22°C si è evidenziato un abbattimento, sebbene meno marcato soprattutto nei campioni di würstel. Conclusioni. I nostri risultati confermano che l’incorporazione di agenti antimicrobici direttamente negli imballaggi polimerici potrebbe produrre interessanti sviluppi permettendo alle industrie di combinare le potenzialità antimicrobiche all’attività protettiva del packaging. L’impiego di questo tipo di coating potrebbe essere proposto per contrastare la crescita non solo di L. monocytogenes, ma anche di altri batteri deterioranti e di patogeni alimentari in differenti matrici che possono essere sottoposte a conservazione.

2006 - In vivo toxicity evaluation of a microsystem for polymyxin B oral administration [Abstract in Atti di Convegno]
Sala, Nicoletta; Coppi, Gilberto; Messi, Patrizia; A., Coppi; Iannuccelli, Valentina
abstract

Abstract Summary: The aim of this study was to investigate in rats the toxicity of calcium alginate/chitosan microparticles, designed as a system to orally administer polymyxin B. Toxicity evaluation was performed after a single oral administration of PMB-loaded microparticles in comparison with unloaded microparticles and pure PMB. Introduction: The development of biodegradable microparticles with mucoadhesive properties and with a size of less than 5 μm could be very useful to promote the absorption of drugs with poor bioavailability via translocation of particles by M cells of Peyer’s patches (PP). These specialized cells staying over mucosa-associated lymphoid tissue (MALT), interspersed by enterocytes in the follicle associated epithelium (FAE), are able to transport via endocytosis a variety of microparticulate matter, macromolecules and microorganisms (bacteria, viruses, protozoae) from gut lumen to intraepithelial lymphoid cells (1). For this reason, the aim of this study was to investigate in rats the toxicity of calcium alginate/chitosan (Ca-ALG/CHT) microparticles, designed as a system to orally administer polymyxin B (PMB), antibiotic agent indicated in the treatment of serious infections caused by susceptible strains of Ps. Aeruginosa, H. influenzae, Escherichia coli, Aerobacter aerogenes, Klebsiella pneumoniae, when less potentially toxic drugs are ineffective or contraindicated. Biodegradable microparticles, prepared by spray-drying a sodium alginate solution containing PMB and subsequent reaction with Ca2+ ions and CHT, have been characterized in vitro and evaluated ex-vivo in previous studies (2). Toxicological evaluation was performed in this study in conformity with European Community regulations controlling experiments on live animals (CEE Council 89/609: Italian D.L.vo. 22-1-92 n. 116) after a single oral administration to male rats of PMB microparticles in comparison with unloaded microparticles and pure PMB. Experimental Methods: Thirty-six male rats (Wistar) from Harlan (Milan, Italy) of the same age, weighing about 200 g were housed alone in a metabolic cage with free access to water, maintained at constant room temperature (21°C). The animals were maintained at controlled temperature (21°C), humidity (50–60%) and day length (12 h) for 1 week before experiments. The toxicity study was performed after single administration to, respectively, 6 control rats and 6 assay rats for each sample: PMB water solution (60 mg/2 ml  300 mg/kg), PMB-loaded microparticle water suspension (500 mg/2 ml  60 mg/2 ml of pure PMB), unloaded microparticle water suspension (440 mg/ 2 ml). The control animals received 2 ml of distilled water. The administration was performed by oral gavage to fed/fasted rats. All treated animals were continuously monitored (mortality, behaviour, clinical signs) during the 24 h following the drug administration and urine samples were collected at 6 and 24 h. All surviving animals were killed 24 h after the treatment. After their death blood samples were collected and several organs were observed in situ to detect macroscopic abnormalities. PMB levels were determined on urine samples and serum, obtained from blood, by a microbiological agar well diffusion method using E. coli as indicator strain. Results and Discussion: PMB solution administration to fasted rats: all animals died within 30’. The only abnormal physical sign noted during post-mortem examination was the presence of an intestinal haemorrhage (Fig. 2), probably causing the death. PMB solution administration to fed rats: no animal died during the 24 h observation following the 300 mg/kg administration, but suffering signs like dyspnoea or haemorrhagic zones rounding the eyes were observed. At necropsy, all dosed rats had enlarged stomach (Fig. 1), probably causing breath problems. Therefore, after intragastric administration, PMB was lethal at a lower dose than that

2006 - Studio del comportamento intracellulare di Legionella pneumophila ed altri batteri acquatici in Acanthamoeba polyphaga [Abstract in Rivista]
Guerrieri, Elisa; Messi, Patrizia; Contri, Miranda; Bondi, Moreno; Borella, Paola
abstract

In questo studio si è ritenuto interssante valutare le interazioni tra alcuni batteri ad habitat idrico e un ceppo di Acanthamoeba polyphaga, al fine di comprendere meglio il ruolo di tali microrganismi nell'ecologia di L.pneumophila.

2006 - Valutazione dell’attività antagonista nei confronti di L.monocytogenes di un coating ibrido applicato su polietilene ottenuto mediante incorporazione di Enterocina 416K1 [Relazione in Atti di Convegno]
Iseppi, Ramona; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Messi, Patrizia; Sabia, Carla; Anacarso, Immacolata; Marini, Michele; Toselli, M; Pilati, Francesco; Manicardi, Giuliano; Bondi, Moreno
abstract

L’attività antagonista dimostrata dai nostri film polietilenici rende promettente l’impiego di questo tipo di coating per contenere e contrastare la crescita di L. monocytogenes, ma possibilmente anche di altri batteri deterioranti e patogeni alimentari in differenti matrici che possono essere sottoposte a conservazione. Inoltre la dimostrazione ottenuta dal nostro studio di una migliore conservazione dei campioni confezionati con i film antibatterici rispetto a quelli di controllo, e evidenziata dalle migliori caratteristiche organolettiche osservate, potrebbe far supporre un vantaggio anche per la shelf life del prodotto.

2006 - Vancomycin-resistant enterococci (VRE) in meat and environmental samples. [Articolo su rivista]
Messi, Patrizia; Guerrieri, Elisa; DE NIEDERHAUSERN, Simona; Sabia, Carla; Bondi, Moreno
abstract

We investigated the spread of vancomycin-resistant enterococci (VRE) in strains from meat and environmental samples and the location of glycopeptide-resistance determinants in VanA isolates. VRE and VSE (vancomycin-sensitive enterococci) resistance patterns to six antimicrobials were also evaluated. A total of 59 meat isolates (35\%) and 119 environmental isolates (26.5\%) were glycopeptide resistant enterococci. In particular, 10.7\% meat isolates belonged to the VanA, 8.3\% to VanB and 16\% to VanC phenotypes. Environmental samples presented 0.7\% VanA, 14.5\% VanB, and 11.4\% VanC strains. Evident differences were not observed among the resistance patterns of VRE and VSE isolates. Neither an important difference was observed comparing the resistance patterns in enterococci from meat and environment. In particular a low incidence of beta-lactamic resistant strains was found, whereas high rates of resistance were observed for streptomycin (85.7\% and 92.8\%), kanamycin (79.7\% and 96\%) and gentamycin (85.1\% and 91.7\%). An intermediate rate of resistant bacteria emerged for erythromycin (35.1\% and 10.5\%). All VanA isolates independent of origin had more plasmids with different molecular weights. PCR amplification of the 732 bp fragment in plasmids from the VanA strains confirmed affiliation to the vanA gene cluster and the extrachromosomal location of the glycopeptide-resistance determinants. Our study suggests that food and environment play a potential role as reservoirs of resistance determinants, prompting the need to undertake epidemiological and molecular studies to evaluate the mobility of these genes.

2005 - Antibiotic resistance and antibacterial activity in heterotrophic bacteria of mineral water origin [Articolo su rivista]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno
abstract

Antibiotic resistance and antibacterial activity were determined on heterotrophic bacteria isolated from mineral waters. Of the 120 isolates Pseudomonas spp. (55.8%) was the predominant group followed by Acinetobacter spp. (14.17%), Flavobacterium spp. (10.83%), Achromobacter spp. (10%), Burkholderia cepacia (3.3%), Agrobacterium/radiobacter (2.5%), Moraxella spp. (1.7%), Aeromonas hydrophila (1.7%). Over 80% of the isolates were resistant to one or more antibiotics and the highest resistance was found for chloramphenicol, ampicillin, colistin and sulfamethizole (60%, 55%, 50% and 47.5%, respectively). Strains with multiple antibiotic resistance (MAR) represented 55% of isolates and the most resistant organism belonged to the genus Pseudomonas. Of 40 randomly selected strains, 27 (67.5%) had antibacterial activity towards one or more indicators. This activity, found in a high percentage in the genus Pseudomonas (92%), emerged mainly against closely related microorganisms. Several producers were active also against Escherichia coli, Salmonella, Listeria monocytogenes and Staphylococcus aureus. Forty-six percent of the isolates harboured 1 to 5 plasmids with molecular weights ranging from 2.1 to 41.5 MDa.

2005 - Biocatalytic reduction of (+)- and (–)-carvone by bacteria [Articolo su rivista]
Cramarossa, Maria Rita; A., Nadini; Bondi, Moreno; Messi, Patrizia; Pagnoni, Ugo Maria; Forti, Luca
abstract

The biotransformation of the two enantiomers of carvone, (–)-(1a) and (+)-(1b), by two bacteria (Pseudomonas putida and Acinetobacter lwoffi) isolated from different environments is reported. The metabolites from the biotransformations carried out in liquid cultures using the sterile TS-2 mineral medium were screened by headspace solid phase microextraction/GC–MS. The results show that these bacteria are efficient tools in the diastereoselective bioreduction of (+)- and (–)-carvone.

2005 - Caratteristiche biologiche responsabili di pressione selettiva in batteri psicrotrofi patogeni e deterioranti isolati da carni macinate - Atti della XIV Conferenza Nazionale OXOID La Sicurezza Microbiologica nella produzione di alimenti per il 21° secolo 1, 115-120, 2005. [Relazione in Atti di Convegno]
Bondi, Moreno; Barozzi, S; Guerrieri, Elisa; DE NIEDERHAUSERN, Simona; Sabia, Carla; Messi, Patrizia
abstract

Alla luce di quanto osservato e per la sempre maggior valenza che i batteri psicrotrofi, patogeni e deterioranti, presentano in campo economico e sanitario, appare importante predisporre opportuni mezzi preventivi di controllo quali ad esempio la riduzione della contaminazione secondaria dei prodotti carnei sia a monte che nel corso delle successive fasi di trasformazione e lo studio di nuove misure in grado di ostacolare la moltiplicazione di tali batteri durante il periodo di conservazione.

2005 - Micro- and macromethod assays for the ecological study of Legionella pneumophila [Articolo su rivista]
Guerrieri, Elisa; Bondi, Moreno; C., Ciancio; Borella, Paola; Messi, Patrizia
abstract

The survival of a strain of Legionella pneumophila (Lp-1) inoculated in artificial water microcosms was investigated with and without an amoebal host and varying environmental conditions, such as biofilm formation, amount of nutrients and incubation temperature. The results obtained using short (micromethod) and long (macromethod) term methods showed that L. pneumophila Lp-1 dies rapidly at 4 degrees C in the macromethod assay. When the same temperature (4 degrees C) was applied to the micromethod assay, L. pneumophila Lp-1 survived for three weeks, although it progressively decreased. At an incubation temperature of 30 degrees C, the aquatic environment was more favourable and better survival emerged in the macromethod; in contrast.. this favourable temperature condition did not improve the survival of L. pneumophila Lp-1 cultured with the micromethod. The role of the protozoa Acanthamoeba polyphaga proved to be indispensable for legionella survival only when environmental conditions become unfavourable. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

2005 - Monitoraggio della presenza di caratteristiche biologiche responsabili di pressione selettiva in batteri psicrotrofi patogeni e deterioranti isolati da carni macinate [Abstract in Rivista]
Bondi, Moreno; Ciancio, C.; Guerrieri, Elisa; DE NIEDERHAUSERN, Simona; Sabia, Carla; Messi, Patrizia
abstract

Obiettivo. Negli ultimi anni si sono moltiplicati gli isolamenti da alimenti di stipiti psicrotrofi capaci di sopravvivere e moltiplicarsi a temperature di refrigerazione. Tra questi un particolare interesse è destato dai “new food-borne pathogens”, cui appartengono le specie Yersinia enterocolitica, Aeromonas hydrophila e Listeria monocytogenes, ma anche da batteri dal genere Pseudomonas, non sempre dotati d’attitudini patogene, ma temuti per le loro potenzialità deterioranti. Abbiamo quindi ritenuto interessante svolgere un’indagine sulla presenza di microrganismi psicrotrofi in 120 campioni di carne macinata, valutando contestualmente negli stessi l’incidenza dell’antibiotico-resistenza e la produzione di batteriocine, importanti caratteristiche biologiche responsabili di pressione selettiva. Metodi. I ceppi degli psicrotrofi patogeni-opportunisti, isolati da alimenti carnei impiegando le metodiche di routine, sono stati testati mediante la valutazione della minima concentrazione inibente (MIC) nei confronti di 12 antibiotici comunemente impiegati in terapia. La produzione di batteriocine è stata determinata utilizzando la tecnica del “deferred antagonism” Risultati. La percentuale di isolamento delle specie psicrotrofe patogene è risultata pari al 5.8% per Aeromonas hydrophila, 2.5% per Listeria monocytogenes e 0.8% per Yersinia enterocolitica. Nei ceppi isolati sono risultate frequenti le resistenze multiple: il 22.2% ha infatti evidenziato multiresistenza a nove antibiotici ed il 3.5% ad undici dei dodici testati. Il 56.2% degli stipiti presi in esame ha mostrato la presenza di plasmidi ad alto peso molecolare trasferibili per coniugazione in parte responsabili dei profili di resistenza. Conclusioni. Desta notevole preoccupazione la possibilità di trasferimento di tali plasmidi dai ceppi resistenti ad altri sensibili, compresi i patogeni. Obiettivo prioritario degli organismi sanitari preposti dovrà quindi essere la razionalizzazione dell’utilizzo degli antibiotici sia in medicina che in zootecnia, dal momento che il loro uso indiscriminato viene considerato il principale responsabile dell’ampia diffusione di microrganismi resistenti negli alimenti e nell’ambiente.

2005 - Role of direct bacterial interference and biofilm in legionella pneumophila water ecology [Abstract in Rivista]
Messi, Patrizia; Bondi, Moreno; Marchesi, Isabella; Borella, Paola; E., Guerrieri
abstract

Aim of the present study was to investigate the interactions occurring between Legionella and other aquatic bacteria, particularly within the biofilm

2005 - Ruolo dell’interferenza batterica e del parassitismo nell’ecologia di Legionella pneumophila [Abstract in Rivista]
Guerrieri, Elisa; Bondi, Moreno; Borella, Paola; Marchesi, Isabella; Messi, Patrizia
abstract

Obiettivi. Numerosi studi hanno ampiamente dimostrato che i protozoi rivestono un ruolo cruciale nell’ecologia di Legionella pneumophila, mentre meno nota è l’influenza dei batteri idrici, in grado di interferire con la sopravvivenza e la crescita dell’ospite protozoario. Al fine di comprendere meglio tale interferenza indiretta, abbiamo indagato la capacità di L. pneumophila (sierogruppo 1 e 7-14) e altri batteri acquatici di entrare e moltiplicarsi all’interno delle amebe. Metodi. Co-culture dei batteri in esame con un ceppo di Acanthamoeba polyphaga sono state allestite in Synthetic Tap Water (STW), incubate a 30°C e osservate per 24 ore, determinando ad intervalli regolari le conte intra ed extra cellulari. Risultati. Entrambi i ceppi di L. pneumophila sono risultati un grado di entrare e trovare riparo all’interno dell’ameba, ma non di moltiplicarsi, probabilmente a causa del breve periodo di incubazione. Burkholderia cepacia, Pseudomonas aeruginosa, Pseudomonas fluorescens e Aeromonas hydrophila hanno mostrato una maggior capacità di ingresso e replicazione intracellulare. Nelle co-colture di A. polyphaga e L. pneumophila (sierogruppo 1) condotte in presenza dei batteri acquatici è stato osservato che B. cepacia era in grado di ridurre l’ingresso di legionella nel protozoo. L’analisi microscopica delle co-colture, ha permesso di rilevare due differenti comportamenti. Il primo, mostrato da L. pneumophila e B. cepacia, era caratterizzato dalla presenza di pochi batteri all’interno delle cellule infettate del protozoo e dall’assenza di lisi entro 24 ore di incubazione. Il secondo, osservato in A. hydrophila e P. fluorescens, ha mostrato la presenza di un elevato numero di batteri intracellulari ed una lisi violenta dopo poche ore di co-incubazione. Conclusioni. Questo studio conferma la capacità dei batteri appartenenti alla naturale microflora degli habitat acquatici di interferire con i protozoi e quindi, indirettamente, con l’ecologia di L. pneumophila.

2005 - Study of five penicillinase producing Neisseria gonorrhoeae isolated in Italy. [Articolo su rivista]
Sabia, Carla; Bondi, Moreno; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Manicardi, Giuliano
abstract

Five penicillinase producing Neisseria gonorrhoeae (PPNG) were isolated from urethral specimens of men admitted to the "Santa Chiara" Hospital (Trento, Italy). All strains proved to be resistant to penicillin and ampicillin, and sensitive to cefuroxime, erythromycin, tetracycline, spectinomycin, nalidixic acid and ciprofloxacin. PPNG plasmid profiles showed that four of the isolates carried the 3.2 MDa "Africa" plasmid and one the 4.5 MDa "Asia" plasmid, the two well-known phenotypes reported in the USA and Europe as well as in Asian and African countries. Membrane matings were performed using N. gonorrhoeae carrying the 24.5 MDa conjugative plasmid as donors and E. coli K12 J 53 as recipient. The transfer of beta-lactamic antibiotic resistance was supported by the presence of 4.5 or 3.2 MDa plasmid bands and by beta-lactamase production in the transconjugants. Restriction analysis of Asian and African plasmids is reported.

2005 - Valutazione della resistenza ad antibiotici e biocidi in ceppi di Listeria monocytogenes isolati da alimenti [Abstract in Rivista]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno; Quaglio, Giampaola
abstract

Obiettivo. Recentemente, accanto al fenomeno dell'antibiotico resistenza, viene riportata una ridotta sensibilità dei microrganismi ai biocidi, il cui utilizzo sembrerebbe inoltre contribuire alla selezione ed alla persistenza di batteri antibiotico-resistenti negli alimenti. Tra i patogeni di interesse in questo contesto, particolare attenzione viene rivolta a Listeria monocytogenes, agente eziologico di gravi infezioni, la cui terapia risulta talvolta fallimentare per l'inefficacia dei chemioterapici impiegati. Data l’ampia diffusione ambientale di questo patogeno, malgrado gli interventi di sanitizzazione attuati in ambito industriale, ci è sembrato interessante svolgere un’indagine sulla circolazione della resistenza ad entrambe le tipologie di composti in ceppi di L. monocytogenes isolati da campioni alimentari. Metodi. 62 stipiti di L. monocytogenes, isolati da alimenti impiegando le metodiche di routine, sono stati testati mediante la valutazione della minima concentrazione inibente (MIC) nei confronti di 8 antibiotici comunemente impiegati in terapia e di 4 biocidi di frequente utilizzo in campo alimentare. Risultati. Vengono confermate, rispetto a nostri precedenti studi, le elevate percentuali di resistenza nei confronti delle cefalosporine di terza generazione (93,5%), mentre si assiste ad un aumento della resistenza a cloramfenicolo (58,1%). Ancora ridotte risultano le percentuali di resistenza a tetraciclina (6,4%) e gentamicina (1,6%). Tutti i ceppi si sono mostrati sensibili a penicillina, ampicillina ed eritromicina. Le MIC determinate sugli stessi stipiti hanno evidenziato la resistenza a concentrazioni elevate nei confronti di glutaraldeide e sodio solfato, mentre si sono mostrati sensibili a benzalconio cloruro e clorexidina. Conclusioni. Anche se fino ad oggi gli studi su antibiotici e biocidi hanno seguito tradizionalmente strade diverse, la contestuale diffusione di entrambi i tipi di resistenza, emersa anche in questo studio, deve far riflettere sulla necessità di controllare e razionalizzare l’utilizzo di entrambi i composti in campo medico, veterinario e nelle industrie alimentari.

2005 - Water ecology of Legionella and protozoan: environmental and public health perspectives [Articolo su rivista]
Borella, Paola; Guerrieri, Elisa; Marchesi, Isabella; Bondi, Moreno; Messi, Patrizia
abstract

Ecological studies on Legionella spp. are essential to better understand the germ sources in the natural environments, the mechanism of entry into man-made water systems and the factors enabling survival and growth in aquatic habitats. Legionella spp exhibits peculiar and multiple strategies to adapt to stressful environment conditions which normally impair other germ survival. These strategies include the ability to enter in a viable but non cultivable (VBNC) state, to multiply intracellularly within a variety of protozoa, such as amoebae, to survive as a free organism within biofilms and to be enhanced/inhibited by the presence of other aquatic bacteria. The host-parasite interaction has been shown to be central in the pathogenesis and ecology of L.pneumophila. The bacterial-protozoan interaction contributes to the amplification of Legionella population in water systems, represents a shelter against unfavourable environmental conditions, acts as a reservoir of infection, and contributes to virulence as primes the pathogen to infect human cells. Legionella is able to survive as a free organism for long periods within biofilms which are widespread in man-made water systems. Biofilm provides shelter and nutrients, exhibits a remarkable resistance to biocide compounds and chlorination, thus representing ecological niches for legionella persistence in the environments. A most extensive knowledge on biofilm-associated legionellae may lead to most effective control measures to prevent legionellosis. Lastly, new perspectives in controlling legionella contamination can arise from investigations on aquatic bacteria able to inhibit legionella growth in natural and artificial water systems.

2004 - Efficacia di biocidi e metalli pesanti nel trattamento di biofilm formati da Legionella pneumophila ed altri batteri acquatici - Atti del XVII Congresso Internazionale “European Countries Biologists Association”, Portorose (Slovenia), 2, 89-97, 2004. [Relazione in Atti di Convegno]
Guerrieri, Elisa; Bondi, Moreno; Messi, Patrizia
abstract

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2004 - Glycopeptide-resistance transferability from vancomycin-resistant enterococci of human and animal source to Listeria spp. [Articolo su rivista]
DE NIEDERHAUSERN, Simona; Sabia, Carla; Messi, Patrizia; Guerrieri, Elisa; Manicardi, Giuliano; Bondi, Moreno
abstract

The glycopeptide-resistance transferability from vancomycin-resistant enterococci (VRE) of clinical and animal origin to different species of Listeria was investigated.Of 36 matings, performed on membrane filter, the glycopeptide resistance was successfully transferred in six attempts, five with donors of animal origin and only one with donors from clinical source. The acquired glycopeptide resistance in Listeria transconjugants was confirmed by the presence of the conjugative plasmid band and by the amplification of the 732-bp fragment of vanA gene in transferred plasmids.Despite the lower number of bacteria used in this study, the source of enterococci influenced the outcome of mating. Moreover transferred VanA plasmid induced a different expression in Listeria transconjugants, suggesting that gene expression might be influenced by species affiliation of recipients.Our data strengthen the opinion that enterococci are an important source of resistance genes for Listeria via the transfer of movable genetic elements. As these strains are commonly found in the same habitats, a horizontal spread of glycopeptide resistance in Listeria spp. could be possible.

2004 - Interferenza di lattobacilli nei meccanismi di ricombinazione come prevenzione naturale alla diffusione dell'antibiotico-resistenza [Abstract in Rivista]
Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Messi, Patrizia
abstract

E’ noto da tempo come i batteri lattici influenzino favorevolmente la salute dell’uomo ed è per questo motivo che ceppi di Lactobacillus e Bifidobacterium sono impiegati nell’allestimento di prodotti probiotici ad azione modulante sulla microflora intestinale. L’integrità di tale ecosistema, fondamentale per la normale funzionalità dell’apparato digerente, contribuisce nel contempo alla salute dell’organismo. Uno dei problemi di sanità pubblica che sta emergendo negli ultimi anni è rappresentato dall’antibiotico-resistenza e la microflora del tratto digestivo umano ed animale, in particolare, viene ritenuta il “reservoir” principale delle resistenze agli antibiotici di tipo plasmidico (fattori R) che possono essere trasferite da un microrganismo all’altro, superando a volte anche le barriere di specie. E’ ipotizzabile quindi che in questo distretto ad alto tenore di microrganismi possano avvenire numerosi scambi genetici, compreso il trasferimento della resistenza agli antibiotici.Scopo della nostra ricerca è stato quello di valutare ”in vitro“ la capacità di L. plantarun 35d e L.plantarum 396/1 di interferire col meccanismo di coniugazione. La capacità di trasferimento dei plasmidi di resistenza è stata valutata utilizzando E.coli NK12 NalR KS Lac+ come ricevente e E.coli RP4 NalS KR Lac- come donatore in tre differenti esperimenti di coniugazione (A, B, C), uno dei quali allestito senza lattobacilli ed impiegato come controllo. (C).I risultati hanno mostrato che le frequenze di coniugazione (ratio transconiuganti/donatori) relative a tre esperimenti, sono influenzate dalla presenza dei due lattobacilli. Le differenze tra i valori delle cariche dei transconiuganti, ottenuti in presenza e in assenza dei lattobacilli, analizzate col t-test per dati appaiati, risultano infatti statisticamente significative (p=0.0131 nel confronto tra A e C ; p= 0.0133 nel confronto tra B e C).La nostra sperimentazione ha quindi dimostrato che la presenza di particolari ceppi di lattobacilli è in grado di interferire col trasferimento “in vitro” dei fattori di resistenza.

2004 - Interferenza microbica: quale ruolo nell’ecologia di Acanthamoeba polyphaga e Legionella pneumophila? [Abstract in Rivista]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno; Borella, Paola
abstract

Data la necessità di comprendere meglio l'ecologia di L.pneumophila al fine di consentire la messa in atto delle giuste misure preventive per controllarne la diffusione, sono stati testati 28 ceppi batterici di provenienza idrica, ascritti in maggior parte al genere Pseudomonas, per la capacità di produrre batteriocine. Di questi 20 (71,4%) sono risultati in grado di produrre batteriocine attivecontro L. pneumophila e 4 (14,3%) si sono mostrati scarsi produttori. Nessuno dei 22 ceppi di legionella testati è risultato in grado di produrre batteriocine. Parallelamente, al fine di ottenere informazioni sui fattori favorenti o inibenti lo sviluppo e la sopravvivenza dei protozoi, sono state allestite co-colture di un ceppo di Acanthamoeba polyphaga associato a L. pneumophila ed altri batteri. E' stata osservata una considerevole variabilità tra i diversi ceppi nella capacità di penetrare nell'ameba e di influenzarne la sopravvivenza e la moltiplicazione.

2004 - Lattobacilli in prodotti alimentari e in probiotici: una prevenzione naturale alla diffusione dell’antibiotico-resistenza [Relazione in Atti di Convegno]
Messi, Patrizia; Sabia, Carla; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Bondi, Moreno
abstract

2004 - Produzione di aromi e fragranze da impiegarsi in campo alimentare mediante biodegradazioni microbiche di terpeni [Relazione in Atti di Convegno]
Bondi, Moreno; Cramarossa, Maria Rita; Forti, Luca; A., Nadini; Pagnoni, Ugo Maria; Messi, Patrizia
abstract

2004 - Ruolo dell’interferenza microbica nell’ecologia di Acanthamoeba polyphaga e Legionella pneumophila [Relazione in Atti di Convegno]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno; Borella, Paola
abstract

2004 - Sensibilità ai biocidi di biofilm formati in vitro da Legionella pneumophila ed altri batteri acquatici [Abstract in Rivista]
Guerrieri, Elisa; Bondi, Moreno; Messi, Patrizia
abstract

Il biofilm è un micro-sistema acquatico che fornisce ai microrganismi una notevole protezione nei confronti dei biocidi e rappresenta una importante nicchia ecologica in cui i batteri acquatici, tra cui L. pneumophila, possono sopravvivere e proliferare. Al fine di poter controllare la presenza e la diffusione di Legionella pneumophila ed altri batteri potenzialmente patogeni ad habitat idrico, appare di fondamentale importanza la conoscenza del ruolo protettivo del biofilm nei confronti di sostanze potenzialmente utilizzabili nella pratica di disinfezione.Nel presente studio è stata testata l’efficacia di alcuni biocidi (clorexidina e bronopol) e ioni metallici (rame e argento) su biofilm formati in vitro da ceppi batterici di derivazione idrica che avevano mostrato una spiccata attitudine ad aderire alle superfici per formare biofilm maturi.È stata valutata la capacità di tali sostanze, addizionate a diverse concentrazioni, di interferire con la formazione del biofilm prodotto in acqua condottata sintetica da sospensioni batteriche. I risultati hanno mostrato che la formazione del biofilm ottenuto da Pseudomonas aeruginosa e Pseudomonas fluorescens non è risultata inibita dai biocidi alle massime concentrazioni testate (250mg/l); leggermente più sensibile è risultato quello prodotto da Legionella pneumophila e Burkholderia cepacia. Al contrario le sospensioni da cui i biofilm si sono originati sono risultate estremamente sensibili alle sostanze in esame, essendo completamente abbattute alle concentrazioni minime testate (10-50mg/l).Parallelamente sono state studiate le potenzialità biocide delle stesse sostanze sui biofilm preformati (7giorni). Questi si sono mostrati insensibili al trattamento con concentrazioni superiori (fino a 1250 mg/l). Il bronopol ha evidenziato le più limitate potenzialità antibatteriche, l’argento ha mostrato una discreta attività, mentre la clorexidina è risultata il biocida più efficace. Queste considerazioni giustificano le notevoli difficoltà che si incontrano nell’eradicare Legionella pneumophila ed altri batteri di interesse per la salute umana dai serbatoi di infezione e rafforzano la necessità di ulteriori approfondimenti.

2004 - Study of two bacteriocins produced by Enterococcus casseliflavus and Ent. faecalis [Articolo su rivista]
Sabia, Carla; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Manicardi, Giuliano; Bondi, Moreno
abstract

The antimicrobial activity of two plasmid-borne bacteriocins produced by Enterococcus casseliflavus IM 416K1 and Ent. faecalis IM 388C and their mating transferability were studied.Both bacteriocins showed antibacterial activity against taxonomically related micro-organisms and Listeria monocytogenes but differ for heat sensitivity, antimicrobial titre, molecular size and class of affiliation. The transferability by mating of the antibacterial properties from producers to Enterococcus faecalis JH2-2 revealed that the bacteriocin-phenotype was linked in both strains to genes located on a 34 MDa plasmid. This result was confirmed by loss of antibacterial activity and immunity after curing treatment.Restriction analysis has shown a different profile of the two conjugative plasmids. Enterocin 416K1 and Enterocin 388C could represent natural antilisterial agents to use in food technology.The transferability of the 34 MDa conjugative plasmids might be considered a possibility for the study of bacteriocins expression in bacterial hosts different from the native strains.

2004 - Utilizzo di lattobacilli nella prevenzione naturale alla diffusione dell’antibiotico-resistenza [Relazione in Atti di Convegno]
Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Guerrieri, Elisa; Messi, Patrizia
abstract

2004 - Valutazione microbiologica di bioaerosol, del percolato e dei rifiuti solidi conferiti nella discarica controllata di modena [Abstract in Rivista]
R., Roncaglia; Guerrieri, Elisa; Bondi, Moreno; Fantuzzi, Guglielmina; Messi, Patrizia; Neglia, Rachele Giovanna; Aggazzotti, Gabriella
abstract

La presente indagine è stata condotta nella discarica controllata di Modena allo scopo di valutare la presenza di microrganismi indicatori di possibile rischio biologico. Dai risultati ottenuti emerge una sostanziale assenza di patogeni trasmissibili per via orale ed inalatoria.Le cariche dei microrganismi indicatori di contaminazione fecale sono risultate non particolarmente elevate e assenti nei campioni di aerosol. Non sembrano sussistere rischi significativi per la salute dei lavoratori

2003 - Bacteriocin-like substance (BLS) production in Aeromonas hydrophila water isolates [Articolo su rivista]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno
abstract

30 Aeromonas hydrophila water isolates were tested for bacteriocin-like substance (BLS) production using a target panel of closely related microorganisms and other Gram-positive and Gram-negative bacteria, including food-borne pathogens. A, hydrophila showed antibacterial activity against one or more indicator microorganisms, but the activity emerged only with non-phylogenetically related genera or species. In particular all A. hydrophila showed antibacterial activity against one or more of the tested Staphylococcus strains, five against Listeria spp. (Listeria seeligeri, Listeria welshimeri and Listeria ivanorii), and eight presented a weak antagonistic activity towards Streptococcus agalactiae and Lactobacillus spp. Inhibitory activity was not observed against the other Gram-positive (Listeria monocytogenes, Listeria innocua and Enterococcus spp.) and Gram-negative tested strains, including Aeromonas sobria. Aeromonas caviae and the same A. hydrophila. when used as indicator. Anti-staphylococcal activity was observed with a gradual increase of the inhibition zone during incubation and seemed to be influenced by A. hydrophila hemolytic expression. Extrachromosomal analysis showed the presence. in 70% of the strains. of one to five plasmids with molecular masses ranging from 2.1 to 41.5 MDa, but it was not possible to relate this result with BLS production. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

2003 - Bacteriocin-producing Enterococcus casseliflavus IM 416K1, a natural antagonist for control of Listeria monocytogenes in Italian sausages ("cacciatore"). [Articolo su rivista]
Sabia, Carla; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Manicardi, Giuliano; Bondi, Moreno
abstract

The bacteriocinogenic Enterococcus casseliflavus IM 416K1 (Bac+) isolated from Italian sausages or its bacteriocin Enterocin 416K1, with strong anti-listerial activity, were used in trials to evaluate the effect on Listeria monocytogenes NCTC 10888 in artificially inoculated Italian sausages ("cacciatore"). In trials with Enterocin 416K1 added, L. monocytogenes showed a significant reduction as compared to the control inoculated with L. monocytogenes alone. The elimination of L. monocytogenes was only obtained in sausages added with E. casseliflavus IM 416K1 Bac+.

2003 - Batteriocine in VRE (Vancomycin Resistant Enterococci) : dal vantaggio ecologico una ulteriore componente di virulenza [Relazione in Atti di Convegno]
DE NIEDERHAUSERN, Simona; Sabia, Carla; Guerrieri, Elisa; Messi, Patrizia; Manicardi, Giuliano; Bondi, Moreno
abstract

2003 - Biodegradazioni microbiche di terpeni per la produzione di aromi e fragranze [Relazione in Atti di Convegno]
Bondi, Moreno; Cramarossa, Maria Rita; Forti, Luca; Nadini, A; Pagnoni, Ugo Maria; Messi, Patrizia
abstract

2003 - Biotrasformazioni di terpeni mediate da batteri ambientali [Abstract in Atti di Convegno]
Bondi, Moreno; Cramarossa, Maria Rita; Forti, Luca; Messi, Patrizia; A., Nadini; Pagnoni, Ugo Maria
abstract

Negli ultimi anni si è avuto un incremento della produzione biotecnologica di aromi chimici naturali (NACs) legato alla richiesta, da parte dei consumatori, di prodotti biologici. L’interesse per gli aromi naturali rispetto a quelli ottenuti per sintesi chimica ha comportato un aumento della produzione “microbica” di bioaromi. Un aroma per essere definito “naturale” deve essere ottenuto da sostanze naturali attraverso trasformazioni biocatalitiche che utilizzino enzimi o microrganismi ed il prodotto finale deve essere identico ad una sostanza nota già presente in natura. Se lo stesso prodotto è ottenuto per sintesi chimica si può classificare come “natural identic”. I terpenoidi sono precursori naturali poco costosi, facilmente reperibili e rinnovabili e costituiscono il maggior gruppo di prodotti naturali con piu’ di 22.000 strutture conosciute. I monoterpeni, che sono ampiamente distribuiti in natura e sono fra i componenti principali degli olii essenziali di erbe, spezie e conifere, costituiscono una classe di substrati precursori molto utili e, dato il loro utilizzo nell’industria profumiera ed alimentare, sono prodotti di partenza ideali per la produzione biotecnologica di NACs.Sono note in letteratura diverse bioconversioni di monoterpeni per la produzione di aromi naturali con vari microorganismi, in particolare funghi e lieviti, mentre sono state meno sudiate le bioconversioni con batteri. In questo lavoro sono riportate le biotrasformazioni di citrale e carvone biocatalizzate da alcuni batteri ambientali: Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas cepacia, Pseudomonas fluorescens, Acinetobacter lwoffi e Flavobacterium spp. In tutte le bioconversioni le uniche fonti di carbonio e di energia sono rappresentate dai monoterpeni. Pseudomonas putida riduce selettivamente il carvone a diidrocarvone, mentre Acinetobacter lwoffi, Flavobacterium spp. e Pseudomonas aeruginosa sono in grado di ridurre ulteriormente il prodotto a diidrocarveolo. Non vi è alcuna bioconversione né con la Pseudomonas cepacia nè con la Pseudomonas fluorescens. La citrale (miscela di nerale e geraniale) è ridotta a nerolo e geraniolo da Acinetobacter lwoffi mentre con Pseudomonas putida si ha un’ulteriore riduzione a citronellolo. La bioconversione con Flavobacterium spp è caratterizzata da un cammino riduttivo, che porta dapprima alla formazione di nerolo e geraniolo e successivamente a citronellolo, e da un cammino degradativo, in cui si ottiene il 6-metil-5-epten-2-one (un prodotto lineare di degradazione dei terpeni) nelle prime 24 ore e successivamente CO2 ed H2O. Lo stesso cammino degradativo si ha anche con Pseudomonas cepacia, con Pseudomonas fluorescens e con Pseudomonas aeruginosa.

2003 - Controllo e significato della contaminazione microbica ambientale in un impianto di trasformazione alimentare [Relazione in Atti di Convegno]
Messi, Patrizia; Guerrieri, Elisa; Longagnani, M; Campani, L; Bondi, Moreno
abstract

2003 - Indagine sulla diffusione di Enterococchi vancomicino-resistenti (VRE) in matrici alimentari ed ambientali [Relazione in Atti di Convegno]
Messi, Patrizia; Guerrieri, Elisa; Sabia, Carla; DE NIEDERHAUSERN, Simona; Bondi, Moreno
abstract

2003 - Influence of the manufacturing environment on food packaging microbial contamination [Articolo su rivista]
Guerrieri, Elisa; Bondi, Moreno; M., Fancinelli; Messi, Patrizia
abstract

Nell’arco di un anno sono stati effettuati presso uno stabilimento produttore di dispositivi di chiusura di contenitori per liquidi alimentari, 8 campionamenti di aria, superfici e prodotto finito, al fine di valutare l'entità e l'andamento stagionale delle cariche microbiche ambientali e studiarne l’influenza sulla qualità microbiologica del prodotto. I prelievi d’aria in cui si sono riscontrate le cariche più elevate sono quelli relativi al deposito outdoor, mentre risulta più contenuta e simile all’aria esterna la contaminazione dei reparti produttivi e dei magazzini. Le superfici più contaminate sono risultate quelle delle macchine temporaneamente non utilizzate, suggerendo la validità delle tecniche di detersione impiegate durante il processo produttivo. Le cariche microbiche riscontrate sul prodotto finito sono apparse nel complesso notevolmente contenute. Leggermente più elevati si sono mostrati i valori relativi ai campioni prelevati dal magazzino e dai silos di stoccaggio, indicando come uno dei maggiori contributi alla contaminazione del prodotto sia l’esposizione all’aria ambientale in fase di movimentazione e/o di imballo finale. Dall’analisi dei risultati espressi come medie stagionali emerge un andamento correlabile con le condizioni di temperatura ed umidità, caratteristiche delle stagioni climatiche dell’anno, con un picco nel periodo estivo.

2003 - Ruolo di Acanthamoeba poyphaga nell’ecologia microbica di Legionella pneumophila ed altri batteri ad habitat acquatico - Atti del XVI Congresso Internazionale “European Countries Biologists Association 2, 33, 40, 2003. [Relazione in Atti di Convegno]
Guerrieri, Elisa; Bondi, Moreno; Foschieri, F; Ciancio, C; Marchesi, Isabella; Messi, Patrizia
abstract

2003 - Sopravvivenza di Micrococcus spp. e Penicillium spp. isolati da capsule per bottiglie ed inoculati in acque minerali naturali [Articolo su rivista]
E., Guerrieri; Messi, Patrizia; M., Facinelli; Bondi, Moreno
abstract

E' stata studiata la capacita' di sopravvivenza di un ceppo batterico (Micrococcus spp.) e di uno stipite fungino (Penicillium spp.), isolati dalla superficie di capsule in plastica e inoculati in diversi campioni di acqua minerale naturale. Micrococcus spp. ha mostrato una scarsa capacita' di sopravvivenza, risultando completamente abbattuto sei giorni dopo un inoculo di 9 x 10*[4) ufc/ml in tutti i tipi di acqua minerale utilizzati per lo studio ed entro le 24 ore in acqua addizionata di CO2; Penicillium spp. nelle acque minerali non carbonate e' risultato in grado di sopravvivere a lungo, ma non di moltiplicarsi, mantenendo pressoche' costante la carica durante tutta la sperimentazione (120 giorni), indipendentemente dalla carica iniziale. Al contrario, in acqua minerale addizionata di CO2, dopo una iniziale conservazione della carica, si e' osservato un abbattimento seguito dalla totale scomparsa del ceppo, con tempi differenti in relazione alle cariche iniziali utilizzate

2003 - Studio sulla sopravvivenza di Legionella pneumophila in microhabitat idrici artificiali: macrometodo [Abstract in Rivista]
Messi, Patrizia; Guerrieri, Elisa; C., Ciancio; Marchesi, Isabella; Bondi, Moreno
abstract

Mentre risulta ormai accertato il ruolo di A.polyphaga nella sopravvivenza di L. pneumophila in ambiente idrico, poco o nulla si conosce sull’influenza della flora batterica albergata nello stesso habitat. Nel presente studio è stata valutata in “macrometodo” la sopravvivenza di uno stipite di L.pneumophila inoculato singolarmente o in associazione con due ceppi di Pseudomonas spp. di provenienza idrica e uno di Acanthamoeba polyphaga, in bottiglie di vetro Pyrex da 1 litro contenenti acqua condottata filtrata, incubate a 4°C e a 30°C. I risultati mostrano che a 30°C L.pneumophila presenta un andamento pressochè sovrapponibile sia quando inoculata singolarmente che in tutti i campioni in cui è presente l’ameba, con una carica di poco inferiore a 104 UFC/ml, anche a 40 giorni dall’inoculo. Quando è posta a 4°C, L.pneumophila, inoculata singolarmente risulta abbattuta già dopo 24-48 ore, mentre associata all’ameba presenta solo un lieve decremento che consente, comunque, di rilevare ancora il microrganismo almeno fino al 40° giorno. Questa sopravvivenza riconducibile alla condizione di parassita, sembra essere influenzata negativamente dalla presenza di batteri di origine idrica; infatti nei campioni in cui sono stati inoculati P.fluorescens o P. putida insieme al protozoo, si assiste ad un più accentuato calo iniziale seguito da un andamento pressochè costante. Al contrario nei campioni in cui, in assenza di A.polyphaga, è associata con i batteri idrici L. pneumophila mostra la migliore capacità di sopravvivenza, probabilmente a causa di un effetto sinergico dovuto ai due batteri.

2003 - studio sulla sopravvivenza di Legionella pneumophila in microhabitat idrici artificiali: micrometodo [Abstract in Rivista]
Guerrieri, Elisa; Bondi, Moreno; F., Foschieri; Marchesi, Isabella; Messi, Patrizia
abstract

Considerata l’ampia diffusione, la gravità della patologia causata da Legionella pneumophila e l’aumentata la sopravvivenza in ambiente idrico all’interno di biofilm o intracellularmente nei protozoi, ci è sembrato interessante intraprendere uno studio in microhabitat idrici artificiali per ottenere maggiori informazioni circa la sopravvivenza di L. pneumophila all’ambiente naturale ed il suo comportamento in presenza di batteri idrici appartenenti a specie ritenute responsabili della formazione di biofilm e con A. polyphaga. Gli esperimenti sono stati eseguiti in “micrometodo” utilizzando piastre a 12 pozzetti a fondo piatto addizionati di acqua autoclavata e valutando il comportamento degli organismi in esame, presi singolarmente o in associazione, a differenti temperature (4 e 30°C) di incubazione. I risultati mostrano che L.pneumophila posta a 30°C subisce un calo fisiologico di circa 1 log nei primi 2 giorni, appare costante nei successivi 12 giorni e scompare intorno al 17° giorno. Un calo iniziale più accentuato e un andamento altalenante emerge quando il microrganismo è inoculato insieme ad A. polyphaga, che si risolve però con una più prolungata sopravvivenza. Cariche più ridotte sono risultate dall’incubazione a 4°C , che ha consentito però il rilevamento di L. pneumophila per tempi ancora più lunghi. Alla luce dei risultati ottenuti si può ipotizzare che la legionella è capace di sopravvivere anche da sola nell’ambiente extracellulare purchè in questo vi ritrovi i nutrienti necessari; qualora queste sostanze vengano meno, il batterio subisce un drastico abbattimento se non sono presenti protozoi da parassitare.

2002 - Aerodiffusione di microrganismi e rischio infettivo/allergico [Relazione in Atti di Convegno]
Bondi, Moreno; Messi, Patrizia
abstract

2002 - Antibiotico-resistenza e sostanze ad attività antibatterica: caratteristiche biologiche responsabili di pressioni selettive in batteri isolati da acque minerali naturali [Abstract in Rivista]
Messi, Patrizia; Bondi, Moreno; Guerrieri, Elisa
abstract

Su un campione di 120 batteri isolati da acque minerali naturali del commercio è stata valutata la presenza di ceppi antibiotico-resistenti e BLS (Bacteriocin-Like Substances) produttori. Le identificazioni biochimiche relative ai ceppi in esame hanno rivelato la presenza di una eterogenea flora autoctona Gram-negativa, appartenente ai generi Pseudomonas (59.8%), Acinetobacter (14.8%), Flavobacterium (10.7%), Achromobacter (9.8%), Moraxella (1.6%), Agrobacterium/radiobacter (2.5%), A.hydrophila (0.8%). L’80% degli stipiti è risultato resistente ad uno o più dei 12 chemio-antibiotici saggiati con l’antibiogramma (ampicillina, carbencillina, streptomicina, kanamicina, gentamicina, tobramicina, amikacina, tetraciclina, cloramfenicolo, colistina, acido nalidixico, sulfametizolo). Le percentuali di resistenza sono apparse più elevate per cloramfenicolo (60%), ampicillina (55%), colistina (50%) e sulfametizolo (47,5%). La valutazione delle minime concentrazioni inibenti ha messo in evidenza un ampio range di distribuzione delle resistenze ed in alcuni casi valori di MIC50 e MIC90 particolarmente elevati. Sostanze ad attività antibatterica (batteriocine o BLS) sono state riscontrate in una elevata percentuale (70%) dei ceppi saggiati ed in particolare nel genere Pseudomonas. Infine, nel 46% dei microrganismi é stato possibile evidenziare plasmidi di diverso peso molecolare, la cui espressione a livello fenotipico potrebbe forse essere individuata nelle caratteristiche biologiche responsabili di pressioni selettive, che permettono al microrganismo di prevalere su altri appartenenti alla stessa specie, o a specie diverse, alberganti lo stesso habitat.

2002 - Enterocin 416K1, an antilisterial bacteriocin produced by Enterococcus casseliflavus IM 416K1 isolated from Italian sausages. [Articolo su rivista]
Sabia, Carla; Manicardi, Giuliano; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Bondi, Moreno
abstract

Enterococci (118) from Italian sausages were tested for the production of antimicrobial substances. Of these, 7.6\% showed antibacterial activity against one or several closely related microorganisms used as indicators. Enterococcus casseliflavus IM 416K1 in particular produced a bacteriocin (Enterocin 416K1) with strong anti-listerial antagonistic activity. The bacteriocin withstood heating at 90 degrees C for 120 min and storage at 4 degrees C for 6 months. The mode of action was identified as bactericidal. The crude activity of Enterocin 416K1 was linked to a molecule with an apparent molecular weight smaller than 5 kDa. Plasmid analysis of E. casseliflavus IM 416K1 revealed the presence of four plasmids with different molecular weights (34, 11, 7 and 3.3 MDa). All the Bac- variants produced by curing experiments showed loss of the single plasmid of 34 MDa. Bacteriocin activity and immunity production may be linked to genes located on that same plasmid.

2002 - Evoluzione di batteri ad habitat idrico inoculati in acque minerali confezionate in contenitori di vetro, PET e brik [Abstract in Rivista]
Bondi, Moreno; Guerrieri, Elisa; Messi, Patrizia
abstract

La flora autoctona dell’acqua minerale risulta costituita prevalentemente da batteri aerobi Gram negativi non fermentanti che ne caratterizzano la “facies microbica”. Tali microrganismi possono subire dopo il confezionamento variazioni quantitative in relazione a tipo di contenitore, modalità, tempi e condizioni di stoccaggio, creando problemi di tipo commerciale e di sanità pubblica. A questo proposito è stata condotta un’indagine su tre batteri di isolamento idrico (P. putida, P. fluorescens, S. maltophilia), inoculati in acque minerali confezionate in differenti tipi di contenitore (vetro, PET, brik), per monitorarne l‘evoluzione in condizioni di stoccaggio simili a quelle che ne precedono la vendita.Lo studio ha mostrato che le cariche batteriche dopo 7 gg presentano concentrazioni di poco inferiori a quelle iniziali; dopo 20 gg la flessione si fa più evidente (diminuzioni di circa due log per vetro e brik , e fino a 3 log per PET) e dopo 40 gg le cariche si riducono ulteriormente per vetro e brik e più decisamente per PET. Le analisi sensoriali eseguite col panel test, sono risultate positive dopo una settimana per i campioni in PET inoculati con S. maltophilia e dopo 8 settimane per quelli in vetro inoculati con S. maltophilia e, in misura minore, con P. fluorescens. Le analisi preliminari in gas-massa, condotte per individuare un metabolita in grado di indirizzare il riconoscimento dei batteri presenti, hanno messo in evidenza differenze significative quando i tre tipi di contenitore e le tre specie microbiche sono stati confrontati sulla base della produzione di aldeidi e dimetil disolfuro. Significative differenze sono emerse tra vetro e PET, e vetro e brik per quello che riguarda la presenza di aldeidi e tra P. fluorescens e S. maltophilia per dimetil disolfuro.

2002 - Indagine sulla circolazione di enterococchi VRE in acque destinate ad uso potabile [Abstract in Rivista]
Guerrieri, Elisa; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Sabia, Carla; Scialoja, Maria Grazia; Bondi, Moreno
abstract

Tra i patogeni opportunisti gli enterococchi rappresentano uno dei generi più temuti, soprattutto a causa della loro frequente insensibilità agli antibiotici di prima scelta, nonché a quelli impiegati come estrema possibilità terapeutica: vancomicina e teicoplanina. Enterococchi vancomicino-resistenti (VRE) sono infatti stati isolati con sempre maggior frequenza da acque reflue, alimenti di origine animale e feci di individui sani. Non esistono tuttavia in letteratura segnalazioni riguardo la presenza di VRE nelle acque potabili, dato di particolare importanza per meglio comprendere la diffusione dei geni responsabili di tali fenotipi di resistenza. Ci è sembrato pertanto interessante valutare la sensibilità a vancomicina e teicoplanina in 38 enterococchi isolati da acque destinate ad uso potabile. Sei ceppi, risultati appartenere alla specie E. faecalis, hanno mostrato una MIC (Minima Concentrazione Inibente) pari a 4 mcg/ml per vancomincina e tra 1 e 2 mcg/ml per teicoplanina. Tali valori, per questa specie, sono riconducibili al fenotipo definito VanB, caratterizzato da una resistenza trasferibile alla vancomicina, con MIC comprese tra 4 e 1024 mcg/ml, e dalla sensibilità alla teicoplanina con valori di MIC tra 0,25 e 2 mcg/ml. In particolare due dei sei ceppi esaminati potrebbero essere ascritti al fenotipo Van B avendo evidenziato la presenza di un plasmide ad alto peso molecolare che, come descritto da altri autori, potrebbe albergare il trasposone responsabile di tale fenotipo. Questo dato dovrà essere confermato tramite PCR e studi di coniugazione batterica.

2002 - Indagine sulla circolazione di enterococchi VRE in acque destinate ad uso potabile- Poster presentato al 40° Congresso Nazionale SITI, 1, 131, Cernobbio, 8-11 settembre 2002. [Relazione in Atti di Convegno]
Guerrieri, Elisa; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Sabia, Carla; Scialoia, M. G.; Bondi, Moreno
abstract

2002 - Possibili interazioni tra flora fungina rilevata in insaccati crudi stagionati e nelle relative camere di stagionatura [Relazione in Atti di Convegno]
Bondi, Moreno; Maini, S.; Messi, Patrizia
abstract

2002 - Sensibilità a vancomicina e teicoplanina in ceppi di Enterococcus spp. isolati da acque superficiali destinate ad uso potabile [Relazione in Atti di Convegno]
Messi, Patrizia; Guerrieri, Elisa; DE NIEDERHAUSERN, Simona; Sabia, Carla; Scialoja, M. G.; Bondi, Moreno
abstract

2002 - Studio del comportamento di microrganismi isolati da capsule per bottiglie inoculati in campioni di acqua minerale [Relazione in Atti di Convegno]
Guerrieri, E.; Bondi, Moreno; Fancinelli, M.; Messi, Patrizia
abstract

2002 - Survival of an Aeromonas hydrophila in an artificial mineral water microcosm [Articolo su rivista]
Messi, Patrizia; Guerrieri, Elisa; Bondi, Moreno
abstract

The survival capacity of an Aeromonas hydrophila strain (named SB14) isolated from mineral water was investigated in an artificial mineral water microcosm. The bacterial count of this microorganism was compared with two strains of other species from aquatic environments (Pseudomonas fluorescens SSD and Pseudomonas putida SSC) and a bacterium indicative of faecal pollution (Escherichia coli ATCC 25922). Among the strains, all added to sterile Pyrex glass flasks (11) to yield a final bacterial count of about 5 x 10(6) CFU/ml, A. hydrophila SB14 showed a quite strong survival capacity (150 days). even though the Pseudomonas strains were better adapted to this habitat (more than 240 days). E. coli ATCC 25922 was the least well fitted to survive and was no longer detected after 70 days. When A. hydrophila SB14 was inoculated together with one or two of the above strains, its survival appeared to be dependent on interaction with other organisms. A marked decrease in survival by 30 days, possibly due to antagonistic interaction, was observed when this microorganism was associated with E coli ATCC 25922, and an increase by 30 and 60 days, possibly due to commensalic interaction, was obtained when A. hydrophila SB14 was inoculated with P. fluorescens SSD or P. putida SSC, respectively. (C) 2002 Elsevier Science Ltd. All rights reserved.

2002 - Trasferimento coniugativo di plasmidi codificanti batteriocine ed immunità in E. faecalis 388C e E. casseliflavus 416K1 [Relazione in Atti di Convegno]
Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Manicardi, Giuliano; Messi, Patrizia
abstract

2002 - Trasferimento coniugativo “in vitro” di plasmidi veicolanti resistenza a vancomicina e teicoplanina tra enterococchi Van A e Listeria spp. [Relazione in Atti di Convegno]
Sabia, Carla; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Guerrieri, Elisa; Manicardi, Giuliano; Bondi, Moreno
abstract

Vincitore del PREMIO GIORGIO BIANCHINI

2001 - Detection and preliminary characterization of a bacteriocin (plantaricin 35d) produced by a Lactobacillus plantarum strain [Articolo su rivista]
Messi, Patrizia; Bondi, Moreno; Sabia, Carla; Battini, Renata; Manicardi, Giuliano
abstract

Lactic acid bacteria (134) from Italian sausages were tested for the production of antimicrobial substances (bacteriocins). Six percent of these showed antibacterial activity against one or several closely related microorganisms used as indicators. Lactobacillus plantarum 35d in particular produced a bacteriocin of high activity (320 AU ml(-1)) and a wide range of antimicrobial activity including S. aureus. L. monocytogenes, and A. hydrophila. The bacteriocin withstood heating at 80 degreesC for 120 min and storage at 4 degreesC for 6 months. The mode of action was identified as bactericidal. The apparent molecular weight of the bacteriocin extracted with n-butanol was estimated to be 4.5 kDa. (C) 2001 Elsevier Science B.V. All rights reserved.

2001 - Enterococchi Vancomicino-Resistenti (VRE) di provenienza umana ed animale [Relazione in Atti di Convegno]
Bondi, Moreno; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Sabia, Carla; Guerrieri, Elisa; Manicardi, Giuliano; E., Licata
abstract

Vincitore del PREMIO GIORGIO BIANCHINI

2001 - Flora microbica residente in contenitori per R.S.U. di diversa tipologia ed ubicazione [Relazione in Atti di Convegno]
Bondi, Moreno; Guerrieri, Elisa; Bigliardi, P.; Messi, Patrizia
abstract

2001 - Monitoraggio delle contaminazioni microbiologiche nella produzione di imballaggi alimentari [Relazione in Atti di Convegno]
Guerrieri, Elisa; Bondi, Moreno; Messi, Patrizia; M., Fancinelli
abstract

2001 - Possibili omologie in plasmidi albergati in enterococchi vancomicino-resistenti (vre) provenienti da differenti habitat microbici [Relazione in Atti di Convegno]
Bondi, Moreno; DE NIEDERHAUSERN, Simona; Sabia, Carla; Guerrieri, Elisa; Manicardi, Giuliano; Licata, E.; Messi, Patrizia
abstract

2001 - Produzione di sostanze ad attivita’ antibatterica (bacteriocin-like substances) in Aeromonas hydrophila di provenienza idrica [Relazione in Atti di Convegno]
Bondi, Moreno; Guerrieri, Elisa; Bitonte, F.; Messi, Patrizia
abstract

2000 - Analisi di plasmidi di resistenza alle penicilline in ceppi di Neisseria gonorrhoeae [Relazione in Atti di Convegno]
Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Manicardi, Giuliano
abstract

2000 - Biological characteristics of LABLYS98, a Lactobacillus sporogenes for use as probiotic compound [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; I. D., Marchioretto
abstract

Lactobacillus sporogenes (Bacillus coagulans), a spore-forming lactobacillus chosen as biological agent in a formulation for probiotic use, was cultured in media added with L-lysine monohydrochloride to increase the metabolic potentiality. The resulting strain LABLYS98 is stored at the German Collection of Microorganisms and labelled as DSM 12316. Further studies, carried out on the biological characteristics of LABLYS98, showed high stability, acid resistance, production of a large amount of lactic acid (L+) if compared with the original strain (L. sporogenes), moderate adherence to HEp-2 cells and antibacterial activity against many microorganisms used as indicators (L. monocytogenes, Enterococcus spp., A. hydrophila, etc.)

2000 - Caratterizzazione biologica e molecolare di una batteriocina ad ampio spettro (enterocina 416k1) prodotta da un ceppo di E. casseliflavus [Relazione in Atti di Convegno]
Bondi, Moreno; Sabia, Carla; DE NIEDERHAUSERN, Simona; Messi, Patrizia; Manicardi, Giuliano
abstract

2000 - Ceppi microbici antibiotico-resistenti e batteriocino-produttori in acque minerali naturali [Relazione in Atti di Convegno]
Messi, Patrizia; Bondi, Moreno; Guerrieri, Elisa
abstract

E' stato monitorato un campione di 40 batteri isolati da acque minerali naturali, appartenenti al genere Pseudomonas , Aeromonas, Flavobacterium, Acinetobacter, Xantomonas, Alcaligenes, per determinare la presenza di ceppi antibiotico-resistenti e produttori di battericide. 80% degli isolati è risultato resistente a 1 o più antibiotici e la produzione di battericide è stata documentata nel 70% dei ceppi saggiati.

2000 - Enterocina 416K1, una antagonista naturale per il controllo di Listeria monocytogenes negli insaccati crudi stagionati [Relazione in Atti di Convegno]
DE NIEDERHAUSERN, Simona; Sabia, Carla; Bondi, Moreno; Messi, Patrizia; S., Maini; Manicardi, Giuliano
abstract

2000 - Il rischio biologico degli operatori nelle discariche controllate di rifiuti solidi urbani [Articolo su rivista]
Fantuzzi, Guglielmina; Bondi, Moreno; Messi, Patrizia; Predieri, Guerrino; Aggazzotti, Gabriella
abstract

Questa indagine è stata condotta nel territorio modenese in previsione del futuro attraversamento della discarica controllata dei rifiuti solidi urbani da parte della linea ferroviaria ad alta velocità (TAV) di prossima realizzazione nel nostro paese. Il tracciato della linea per i treni ad alta velocità tra Milano e Bologna prevede nel Comune di Modena l’attraversamento dell’area che ospita il sistema di smaltimento dei rifiuti, costituito da una piattaforma di inertizzazione di rifiuti inorganici e da un insieme di discariche per rifiuti solidi urbani: in particolare è previsto l’attraversamento delle discariche per rifiuti solidi urbani denominati RSU 2 e RSU3.Si è quindi verificato in coloro che per motivi professionali hanno eseguito questi lavori la possibile (anche se del tutto eccezionale) esposizione alle diverse componenti microbiche dei rifiuti solidi urbani.

2000 - Incidenza di enterococchi vancomicino-resistenti (VRE) in allevamenti equini [Relazione in Atti di Convegno]
Bondi, Moreno; Messi, Patrizia; DE NIEDERHAUSERN, Simona; Sabia, Carla; Guerrieri, Elisa; Manicardi, Giuliano; E., Licata
abstract

2000 - Microwave cooking and food safety [Articolo su rivista]
Quaglio, Giampaola; Messi, Patrizia
abstract

Food safety of microwave cooking was investigated. Shrimp samples were inoculated with three strains of L.monocytogenes at a level of 5 x 105 CFU/g. One hundred grams of shrimp were cooked in a microwave oven using a programmed temperature-time treatment based on a modified mathematical model. After cooking, thermally stressed cells were recovered following two enrichment methods. The results showed a significant reduction in L.monocytogenes immediately after cooking; cold enrichment anhanced recovery of heat stressed Listeria. Persistence of Listeria emphasizes the need to refrigerate the food for a limited time after microwave cooking. Potential risk for the consumer and control strategies are discussed.

2000 - Plantaricin 35d, a biopreservative for the control of Listeria monocytogenes in smoked salmon samples [Articolo su rivista]
Messi, Patrizia; Bondi, Moreno; Guerrieri, Elisa; Sabia, Carla; Manicardi, Giuliano
abstract

The antibacterial activity of plantaricin 35d - a bacteriocin produced by the lactobacillus strain Lactobacillus plantarum 35d, isolated from seasoned sausages - has been evaluated against eight strains of Listeria monocytogenes. The active substance has been characterized and the results showed: the optimal temperature for production, the kinetics of growth, the mode of action, the heat-resistance, the stability to time and to different pH values. Subsequently the crude extract substance or the producer micro:organism was added, as biopreservative, in smoked salmon samples artificially contaminated with L, monocytogenes of different source and the bacterial counts during the shelf-life period were evaluated. The study confirmed the active growth of L. monocytogenes in salmon samples at refrigerated temperature whereas the treated samples presented a trend growth lower about 1-3 log during the same period of time. In both tests the difference between the bacterial count remained notable until and over the sixteenth week.

2000 - Presenza di Listeria in matrici alimentari [Articolo su rivista]
Messi, Patrizia; Casolari, Chiara; Fabio, A.; Fabio, Giuliana; Gibertoni, C.; Menziani, Giovanna; Quaglio, Giampaola
abstract

Gli A.A. riportano i risultati di una ricerca svolta nell’arco di un decennio (1989-1999) per valutare la presenza e l’incidenza di microrganismi appartenenti al genere Listeria in diverse matrici alimentari. Sono stati complessivamente esaminati 1366 campioni tra derivati del latte (494), carne e derivati (509), prodotti ittici (183), alimenti vegetali (180). Dai 494 campioni di prodotti caseari sono stati isolati 67 (18%) stipiti appartenenti al genere Listeria di cui 40 (8%) L.monocytogenes. Dai 509 campioni di carne e derivati sono stati isolati 321 (63%) stipiti appartenenti al genere Listeria di cui 77 (15%) L.monocytogenes. Dai 183 campioni di origine marina sono stati isolati 44 (24%) stipiti appartenenti al genere Listeria di cui 14 (7,6%) L.monocytogenes. Nei 180 campioni di alimenti vegetali sono stati rinvenuti complessivamente 6 stipiti (3,3%) appartenenti al genere Listeria, ma non è stato isolato alcun ceppo di L.monocytogenes. La più alta percentuale di isolamento di L.monocytogenes è stata trovata nel salmone affumicato (38%), seguito dalle salsicce (28%) e mozzarelle (16%).

2000 - Sopravvivenza di Listeria monocytogenes in campioni di salmone affumicato artificialmente contaminati [Articolo su rivista]
Quaglio, Giampaola; Messi, Patrizia
abstract

Tra i vari alimenti segnalati quali potenziali sorgenti di listeriosi sta aumentando l'importanza di quelli di origine ittica. Nell'ambito di uno studio sulle infezioni a trasmissione alimentare, ci e' sembrato interessante valutare la sopravvivenza e la velocita' di moltiplicazione di L. monocytogenes, contaminando artificialmente confezioni di salmone affumicato. I risultati preliminari ottenuti sembrano confermare anche in questo alimento la capacita' di sopravvivenza e di moltiplicazione in ambiente refrigerato, con un aumento di 1 log gia' a partire dalla seconda settimana, mentre i valori piu' elevati si sono registrati dalla terza e quarta settimana (2 log). In nessun caso si e' avuta l'inattivazione dei microrganismo, ne' una drastica riduzione riconducibile alla concorrenza vitale di microrganismi deterioranti eventualmente presenti

2000 - Virulence profiles and other biological characters in water isolated Aeromonas hydrophila [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Guerrieri, Elisa; F., Bitonte
abstract

Thirty water isolates of A. hydrophila were tested for potential virulence profiles, antibiotic resistance and Bacteriocin-Like Substances (BLS) production. Cytotoxic activity was present in all strains tested, 87% were hemolytic and 70% adhesive. Lysine decarboxylase reactions (LDC) positivity was correlated with virulence factors: 100% versus cytotoxicity, 84% versus adherence, 76% versus hemolytic activity. The correlation was also present in the LDC-negative strains. Hemolytic and cytotoxic activities were frequently associated: high cytotoxicity, corresponding to high hemolytic activity and vice versa. The in vitro susceptibility of A. hydrophila to 28 antibacterial agents showed that cefotaxime was the most active beta -lactam antibiotic, and Cefuroxime inhibited 90% of the strains. Isolates were resistant to Penicillin G, Ampicillin, Carbenicillin, Amoxicillin, Cephalotin and Cefaclor. Tetracycline, Chloramphenicol, Nitrofurantoine, the quinolones and the aminoglycosides (except Streptomycin) were consistently active. BLS production never emerged against closely-related microorganisms, On the contrary A. hydrophila presented a heteroinhibitory activity against non-taxonomically related genera such as Listeria spp. (L. seeligeri NCTC 11856, L. welshimeri NCTC 11857, L. ivanovii NCTC 11846) and S aureus ATCC 25923. Although a large number of strains showed virulence determinants together with other biological characters such as antibiotic resistance and BLS production, it was not possible to relate these factors to the observed plasmids.

1999 - Allergic and infective risk correlated with workplace envirhonment [Relazione in Atti di Convegno]
Bondi, Moreno; Messi, Patrizia; Fantuzzi, Guglielmina
abstract

1999 - Antimicrobial properties and morphological characteristics of two Photorhabdus luminescens strains [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Sabia, Carla; Contri, Miranda; Manicardi, Giuliano
abstract

The biological properties of two Photorhabdus luminescens isolates (MU1 and MU2) of environmental source and the activity of antimicrobial agar diffusible agents (AADA) produced by the same are reported. With regard to cultural features, two variant forms for P. luminescens MU1 and three for P. luminescens MU2 (including an intermediate phase I-like form) have been found. These three forms differ in biological and biochemical properties: P-lactamase, urease, bioluminescence and antimicrobial agar diffusible substance production associated with the phase I form, were less evident in the intermediate phase I-like MU2 and were absent in phase II form. Antimicrobial activity was present in both strains, with the production of a large amount of a diffusible compound with a wide spectrum of action against bacteria of other genera; a reduced activity against correlated species was also observed. Examination by electron microscopy of MU1 and MU2 purified broth cultures revealed the presence of particles belonging to the class of the phage tail-like bacteriocins, described in recent studies as responsible for antibacterial activity against correlated bacteria, a result never confirmed in vitro. A plasmid of 21 Mdal was observed in all the form variants of P. luminescens MU2, suggesting that plasmids are not involved in the transition from primary to secondary phase; no plasmid was detected in P. luminescens MU1.

1999 - Diffusione del genere Yersinia in diverse matrici alimentari [Articolo su rivista]
Messi, Patrizia; Aggazzotti, Gabriella; A., Fabio; Mantovani, Gabriella; Quaglio, Giampaola
abstract

Yersinia enterocolitica è un microrganismo abbondantemente diffuso nell'ambiente. Sierotipi patogeni sono in grado di infettare l'uomo attraverso la catena alimentare. La caratteristica psicrofilia del microrganismo associato al frequente isolamento da prodotti alimentari giustifica la sua classificazione fra i cosiddetti"patogeni emergenti". Gli Autori riportano i risultati di una indagine effettuata nel modenese su diversi substrati: campioni di alimenti di origine animale, di origine vegetale ecampioni di acqua. Da 736 campioni analizzati sono stati isolati 94 ceppi appartenenti al genere Yersinia spp.: la specie più rappresentata è risultata Y. enterocolitica (40 ceppi, 42.55%) seguita da Y. intermedia (30 ceppi, 31.91%), Y. fredericksenii (13, 13.83%) e Y. kristensenii (4, 4.26%). Sono stati inoltre isolati 7 (7.45%) ceppi atipici. Per quanto concerne la distribuzione all'interno dei biotipi, sierotipi e lisotipi, i più rappresentati sono risultati: il biotipo 1 in tutti i campioni analizzati, i sierotipi 0:4, 16 e 0:4, 10,16 negli stipiti provenienti da alimenti carnei e da campioni d'acqua, 0:10, kl, 34 in quelli di origine vegetale. Il lisotipo Xo è quello riscontratocon frequenza più elevata in tutti i ceppi isolati. In un campione proveniente da alimenti carnei è stato isolato un ceppo di Y. enterocolitica 0:3, lisotipo VIII, considerato patogeno per l'uomo.

1999 - Studio della chemio-antibiotico resistenza in ceppi di Aeromonas hydrophila di provenienza idrica [Relazione in Atti di Convegno]
Messi, Patrizia; Bondi, Moreno; Guerrieri, Elisa
abstract

1996 - Contenitori per rifiuti solidi urbani "R.S.U.":Studio qualitativo e quantitativo della flora microbica. [Articolo su rivista]
Bondi, Moreno; C., Sevignani; Neglia, Rachele Giovanna; Messi, Patrizia; Manicardi, Giuliano; P., Bigliardi
abstract

Gli autori hanno valutato dal punto di vista qualitativo e quantitativo la composizione della flora microbica di campioni prelevati da cassonetti per R.S.U.

1996 - Ricerca di salmonelle in alimenti di origine animale [Articolo su rivista]
Quaglio, Giampaola; Messi, Patrizia; Fabio, Giuliana; C., Gibertoni
abstract

Sono stati ricercati batteri appartenenti al genere Salmonella in diversi alimenti di origine animale

1995 - Effect of PVP (Polyvinylpyrrolidone-iodine) on the conjunctival bacterial flora in cataract surgery: a comparison of two different ways of application [Abstract in Rivista]
Cavallini, G. M.; De Iaco, A.; Delvecchio, G.; Bondi, M.; Messi, P.
abstract

To minimize the conjunctival bacterial flora before cataract surfery, it is recommended the use of PVP-I as a disinfectant on the skin and in the conjunctival sac.

1994 - Caratterizzazione di ceppi di Listeria monocytogenes isolati da alimenti di origine animale [Articolo su rivista]
Casolari, Chiara; Fabio, A.; Menziani, G.; Messi, Patrizia; Quaglio, Giampaola
abstract

E' stata ricercata la presenza di L.monocytogenes in differenti alimenti di origine animale, per studiare la diffusione di questo patogeno

1994 - Caratterizzazione di stipiti di Yersinia enterocolitica di derivazione suina. [Articolo su rivista]
Messi, Patrizia; Licata, E.; Manicardi, Giuliano; Fabio, A.; Bondi, Moreno; Quaglio, Giampaola
abstract

Da uno studio condotto su 214 campioni di origine suina sono stati isolati 15 stipiti di Yersinia enterocolitica, tutti appartenenti al biotipo 4, sierotipo O:3, lisitipo VIII.

1994 - Contenitori per rifiuti solidi urbani "RSU": studio qualitativo e quantitativo della flora microbica [Articolo su rivista]
Bondi, Moreno; C., Sevignani; Neglia, Rachele Giovanna; Messi, Patrizia; Manicardi, Giuliano; P., Bigliardi
abstract

Gli autori hanno valutato dal punto di vista quali-quantitativo la composizione della flora microbica di campioni prelevati da contenitori per R.S.U. in differenti condizioni: ubicazione, tipo di utenza servita, e composizione merceologica del rifiuto.

1994 - MICROBIOLOGIA PER SCIENZE INFERMIERISTICHE [Traduzione di Libro]
Bondi, Moreno; Messi, Patrizia
abstract

Questo testo, rivolto in particolare agli studenti ad indirizzo infermieristico, è una traduzione di una recentissima edizione anglosassone (1993). Poichè in questi paesi la Legislazione Sanitaria è più articolata che in Italia, anche le attività infermieristiche che ne fanno parte sono diverse e vengono attuate da un più ampio complesso di figure,con competenze e specializzazioni differenti. Nello scorrere il testo lo studente si troverà in qualche caso ad incontrare sia situazioni che nel nostro paese non sono contemplate, sia una serie di organismi, comitati e presidi specialistici che, non trovando riscontro nel nostro Sistema Sanitario Nazionale, vengono riportati in lingua originale.

1994 - Metodi di identificazione di stipiti di Y.enterocolitica portatori di plasmidi di virulenza [Articolo su rivista]
Quaglio, Giampaola; Messi, Patrizia; A., Fabio; Manicardi, Giuliano
abstract

In 19 ceppi di Y. enterocolitica biotipo4, sierotipo O3, lisotipo VIII sono stati effettuati tests di laboratorio correlati alla presenza di plasmidi. Nessuna valutazione singolarmente è risultata un reale indicatore di questo fattore d virulenza

1994 - Ricerca di frazioni tossiche in ceppi di Clostridium isolati da campioni di miele [Articolo su rivista]
A., Fabio; Messi, Patrizia; Quaglio, Giampaola
abstract

Frazioni tossiche sono state ricercate in clostridi isolati da mieli italiani

1994 - Strategie di intervento per la disinfezione dei conte¬nitori per rifiuti solidi urbani (R.S.U.) [Articolo su rivista]
Bondi, Moreno; C., Sevignani; Messi, Patrizia; Neglia, Rachele Giovanna; Manicardi, Giuliano; P., Bigliardi
abstract

Gli autori mettono a confronto alcune delle possibili strategie di intervento per la disinfezione di contenitori di rifiuti solidi urbani (R.S.U.) mediante la valutazione di parametri microbiologci prima e dopo i diversi trattamenti.

1993 - Il PVP-I nella prevenzione delle infezioni postoperatorie intraoculari. [Altro]
M., Bondi; Messi, Patrizia; Cavallini, Gian Maria; P., Caruso; A., De Iaco
abstract

Valutazione dell'utilizzo del PVP-I nella prevenzione delle infezioni postoperatorie intraoculari.

1993 - Infezioni cervico-vaginali da Chlamydia trachomatis in un campione di donne asintomatiche: confronto di quattro differenti [Articolo su rivista]
Messi, Patrizia; Rivasi, Francesco; Fabio, A.; Provvisionato, Alberto; Turci, M.
abstract

In campioni cervico-vaginali di 150 donne asintomatiche sono state messe a confronto 4 metodiche in uso per la ricerca di Chlamydia trachomatis. I risultati hanno confermato che l'immunofluorescenza diretta rappresenta la tecnica in grado di rilevare il maggior numero di casi positivi anche in assenza di sintomi

1993 - Microonde nella disinfezione odontoiatrica [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; E., Cantoni; S., Caramaschi; Aggazzotti, Gabriella
abstract

Gli autori hanno valutato l'efficacia di sterilizzazione di un nuovo apparecchio ad emissione di micro-onde di prossima introduzione in campo biomedico. Allo scopo sono stati contaminati artificialmente alcuni strumenti ad uso odontoiatrico in seguito sottoposti a cicli di sterilizzazione di diversa durata.Alla luce dei risultati ottenuti si ipotizzano a nostro parere buone prospettive di utilizzo in campo sanitario per le strumentazioni a micro-onde.

1993 - Presenza di Listeria monocygenes in alimenti di origine marina [Articolo su rivista]
Fabio, Giuliana; Gibertoni, C.; Messi, Patrizia; Quaglio, Giampaola
abstract

Su 83 campioni di alimenti ittici pronti al consumo la presenza di Listeria spp è stata rilevata nel 24% dei campioni e la specie più rappresentata è risultata L.monocytogenes (9 stipiti), ritrovata principalmente in campioni di salmone affumicato.

1993 - Valutazione di tests associati alla virulenza in microrganismi appartenenti al genere Yersinia isolati da alimenti di origine animale e da campioni clinici [Articolo su rivista]
Fabio, A.; Messi, Patrizia; Quaglio, Giampaola
abstract

Su 30 ceppi di Yersinia isolati da carne e su 7 di provenienza clinica sono stati effettuati i principali test di virulenza riportati in letteratura. Nella maggior parte dei casi è emersa una buona concordanza tra alcuni tests che sembrano rappresentare le prove più utilizzabili nella normale routine di laboratorio

1993 - Variazioni degli indici microbici in contenitori per R.S.U. sottoposti a diversi trattamenti di disinfezione [Articolo su rivista]
Bondi, Moreno; C., Sevignani; Messi, Patrizia; Neglia, Rachele Giovanna; Manicardi, Giuliano; P., Bigliardi
abstract

E' stato condotto uno studio comparativo tra alcune metodologie di disinfezione per contenitori di rifiuti solidi urbani (RSU) al fine di mettere a punto uno schema pratico e funzionale, applicabile alla routine operativa dell'Azienda Municipalizzata Igiene Urbana di Modena. Sono state pertanto valutate l'efficacia e la persistenza dell'attivtà antimicrobica su alcuni indici microbici utilzzando vari schemi di trattamento.

1992 - Controllo statistico di qualità e le sue finalità nell'analisi delle acque [Articolo su rivista]
M., Cassinadri; Manicardi, Marcella; Tampieri, Auro; Tartoni, Pier Luigi; Manicardi, Giuliano; Bondi, Moreno; Messi, Patrizia
abstract

Gli autori inquadrano il problema del controllo statistico di qualità riferito alle analisi delle acqua potabiliquale premessa ad uno studio che li ha visti impegnati a svilupparew questa esperienza per oltre due anni.

1992 - Controllo su isolamenti ed identificazioni batteriche [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Manicardi, Giuliano; M., Manicardi; M., Tassinari; Tartoni, Pier Luigi; Tampieri, Auro
abstract

207 campioni di acqua provenienti dalla provincia di Reggio E., sono stati analizzati per la determinazione degli indici di inquinamento fecale (coliformi) utilizzando entrambe le tecniche (MPN ed MF) previste per legge. Pur nel ritretto numero di campioni analizzati gli A.A. confermano l'effettiva affidabilità delle due metodiche suggerendo però l'uso di terreni liquidi (MPN) nel caso di acque precedentemente sottoposte a trattamenti di clorazione.

1992 - Presenza di sostanze mutagene in acque superficiali sottoposte a trattamento di potabilizzazione [Articolo su rivista]
Messi, Patrizia; Bondi, Moreno; N., Fontani; Manicardi, Giuliano
abstract

Allo scopo di valutare se il torrente Enza (RE) possa essere preso in considerazione quale futura fonte alternativa di approvigionamento idrico, sono stati determinati i caratteri chimoio-fisici e batteriologici su campioni prelevati nella sezione di Cerezzolo del medesimo corso d'acqua.

1992 - Valutazione "in vitro" dell'attività antibatterica di ipoclorito e biossido di cloro in acque destinate ad uso potabile [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; N., Fontani; M., Algeri; Neglia, Rachele Giovanna; M., Cassinadri; M., Manicardi; Tampieri, Auro; Tartoni, Pier Luigi
abstract

Gli autori hanno intrapreso uno studio sull'attività antibatterica dei due disinfettanti attualmente più in uso nel trattamento delle acque potabili: ipoclorito e biossido di cloro. L'indagine è stata condotta utilizzando quali germi test, tre ceppi batterici appartenenti a specie di possibile isolamento idrico.

1992 - Valutazione dei parametri di contaminazione ambientale e di sterilità [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Manicardi, Giuliano; M., Manicardi; Tampieri, Auro; Tartoni, Pier Luigi; F., Stella
abstract

Gli autori prendono in considerazione lo studio di alcuni parametri microbiologicvi ed ambientali che devono essere valutati in tutti i casi in cui ci si appresti all'allestimento di un nuovo laboratorio di batteriologia o si intenda operare una vigilanza microbiologica continua in locali adibiti ad analisi di questo genere.

1991 - Streptococcus mutans: classification in bacteriocin-types [Articolo su rivista]
Bondi, Moreno; Neglia, Rachele Giovanna; Messi, Patrizia; Manicardi, Giuliano; Fabio, Ugo
abstract

A sample of S. mutans bacteriocins was studied to obtain a useful outline of strain typing since their synthesis has proved stable and not under plasmidial control. The inhibiting effectiveness against 9 oral streptococci and the sensitivity of mutacins produced by 49 S. mutans strains to heat, chloroform and proteasic activity were evaluated. On the basis of our results the producing strains are classified into five different types. We examine the possibility of obtaining a useful typing with bacteriocins and we discuss the choice of the most suitable number of indicators to arrange the strains in a limited cluster number for epidemiological purpose, or to classify freshly isolated S. mutans strains into bacteriocin-types.

1990 - Use of recent technologies in Chlamydia trachomatis diagnosis: utility and different applications [Articolo su rivista]
Messi, Patrizia; C. A., Provvisionato; Coppini, Maurizio; L., Piccinini
abstract

The authors report the results obtained usin "in situ" hybridization and immunoperoxidase assay to identify Chlamydia trachomatis in samples of man affected by non-gonococcal urethritis

1989 - Chlamydia trachomatis infections in asymptomatic women. Results of a study employing different staining techniques [Articolo su rivista]
Ghirardini, Carla; Boselli, F; Messi, Patrizia; Rivasi, Francesco; Trentini, G. P.
abstract

A total of 300 cervical smears randomly collected from asymptomatic women in a mass-screening program for the detection of cervical carcinoma was investigated for Chlamydia trachomatis infection by the use of Papanicolaou and immunofluorescence staining. Features of chlamydial infection detected in 18 cases by Papanicolaou-stained smears were confirmed in 11 cases with immunofluorescence; not a single case that was negative in the Papanicolaou-stained smears was positive by immunofluorescence. The presence of Chlamydia in the Papanicolaou-stained smears in ten cases, including two cases that were negative by immunofluorescence, was also proven by either immunoperoxidase staining or in situ hybridization. On the other hand, either immunoperoxidase or in situ hybridization gave false-negative results in two of the ten cases. Therefore, the combined use of different techniques demonstrated that false-negative results occurred with all techniques, except with Papanicolaou-stained smears, whose sensitivity is apparently the highest.

1989 - Presenza di batteri appartenenti al genere Yersinia in acque superficiali e di falda [Articolo su rivista]
Quaglio, Giampaola; Aggazzotti, Gabriella; Fabio, A; Messi, Patrizia; Mantovani, G.
abstract

After reviewing national and international writing regarding the prevalence of yersiniae in surface waters and ground waters, the Authors report data about a research carried out in the province of Modena (Italy). Over a period of 16 months (february 1986-may 1987) 89 water samples were examined (55 samples collected from rivers and streams and 34 from wells). During every sampling session two samples were collected; one was taken in a sterile bottle (1000 cm3), one by means of the Moore tampon, allowed to float in the stream for 48 h. Yersinia strains were isolated from 37% of thewater samples; 33 samples gave a positive result. Forty one strains were isolated on the whole; filtration method by Millipore membrane appeared the most suitable technique in order to obtain a good recovery rate. Y. enterocolitica appeared the most represented species (43.8%), followed by Y. intermedia (21.9%) and Y.fredericksenii (17.1%). Five atypical strains were isolated, while no strain belonging to the species Y. kristensenii has been evidenced. No relevant difference in Yersinia presence appeared between surface waters and ground waters. No human pathogenic strain has been evidenced and all the isolates appeared belonging to environmental biogroups, serogroups and phage-types.

1988 - Indagine sulla presenza di stipiti batterici del genere Clostridium in campioni di miele. [Articolo su rivista]
Quaglio, Giampaola; Messi, Patrizia; A., Fabio
abstract

Sono stati presi in esame 20 ceppi di clostridium spp isolati da campioni di miele per quel che riguarda la possibilità di produrre tossine. Quatto stipiti hanno mostrato di possedere attività tossica quando introdotti per via peritoneale su topino albino

1988 - Indagini sul contenuto in fluoro nelle acque profonde del modenese [Articolo su rivista]
Aggazzotti, Gabriella; Fantuzzi, Guglielmina; Messi, Patrizia
abstract

E' stata effettuata una indagine conoscitiva sulle acque della Provincia di Modena relativamente al contenuto dello ione fluoro. La concentrazione dello ione fluoro è risultata inferiore al limite ritenuto valido ai fini della prevenzione della carie dentaria, analogamente a quanto riscontrato nella maggior parte delle regioni italiane

1988 - Presenza di Yersinia spp. in campioni di latte e di feci bovine [Articolo su rivista]
Quaglio, Giampaola; Aggazzotti, Gabriella; Messi, Patrizia; G., Mantovani; A., Fabio
abstract

In 350 campioni di latte e 77 di feci bovine è stata ricercata la presenza di Yersinia spp. La frequenza di contaminazione del latte è risultata dell'1,1%, mentre quella delle feci del 5,2%. In nessun caso è stata isolata Y.enterocolitica

1988 - Presenza di batteri appartenenti al genere Yersinia in alimenti carnei in vendita al dettaglio [Articolo su rivista]
Quaglio, Giampaola; Aggazzotti, Gabriella; Messi, Patrizia; A., Fabio; Mantovani, Gabriella
abstract

E' stata effettuata la ricerca di Yersinia spp in 206 campione di carne cruda. Sono stati isolati 28 stipiti e la specie più rappresentata è risultata essere Y.enterocolitica, di cui 1 appartenente al biotipo 4, sierogruppo 0:3 lisotipo VIII, considerato patogeno per l'uomo

1987 - Production of bacteriocin-like substances by human oral streptococci. [Articolo su rivista]
Fabio, U.; Bondi, Moreno; Manicardi, G.; Messi, P.; Neglia, R.
abstract

A sample of human streptococci (mainly Streptococcus mutans species) from dental plaques was examined in order to evaluate the production frequency and activity spectrum of bacteriocin-like substances (mutacins). 89% of the 55 Streptococcus mutans strains produced substances with a wide spectrum of antibacterial activity. The bacteriocins produced showed a marked inhibitory activity against Gram-positive bacteria. Among the Gram-negative species tested, only Neisseria sicca was inhibited by 25% of Streptococcus mutans strains. Also, 16 strains belonging to oral streptococci other than Streptococcus mutans, were examined for their inhibitory capacity against the same indicator. The authors stress the importance of mutacins production in oral ecology and Streptococcus mutans pathogenicity.

1987 - Valutazione di alcuni tests di virulenza su ceppi di Yersinia isolati da prodotti vegetali [Articolo su rivista]
Quaglio, Giampaola; Aggazzotti, Gabriella; Messi, Patrizia; A., Fabio
abstract

Da 350 prodotti ortensi sono stati isolati 21 ceppi appartenenti al genere Yersinia, di cui 5 appartenenti alla specie Y.enterocolitica. Non è emersa corrispondenza significativa tra i test di virulenza eseguiti sugli isolati

1984 - Conjugal plasmids in group D streptococci [Articolo su rivista]
Bondi, Moreno; Messi, Patrizia; Borghi, V.; Manicardi, G.
abstract

159 strains of group D streptococci isolated from clinical specimens were examinated for plasmids content. Our objective was to study some characters carried by plasmids: drug-resistance, hemolysins and bacteriocin activity. 73,6% of the strains were antibiotic resistant and in 69% of these, the drug-resistance was transferable by conjugation. In mating of S. faecalis subsp. zymogenes strains we could also isolate three different types of transconjugants in hemolytic activity. The interpretation of this observation was facilitated by the research of bacteriocin activity. We also classified the bacteriocins found in our strains into different types.

1984 - Plasmids in Streptococcus faecalis subsp. zymogenes: Transferability and molecular properties [Articolo su rivista]
Manicardi, G.; Messi, Patrizia; Borghi, V.; Bondi, Moreno
abstract

Seven strains of Streptococcus faecalis subsp. zymogenes were studied. Plasmids originally harboured by these bacteria, codifing for drug resistance, hemolysin and gelatinase activity, were transferred to a recipient strain ( JH2 -2) by conjugation. Studies on bacteria in mating showed the formation of protoplasmatic bridges between donors and recipients; these bridges should provide for the passage of genetic material. Kinetics of acquisition of the transferable resistance were carried out in liquid medium. Plasmids harboured in donor and transconjugant strains, responsable for antibiotic-resistance, for hemolysin and gelatinase activity, were analyzed later by agarose gel electrophoresis. These analysis permitted us to demonstrate the presence of many plasmids, some conjugative with a high molecular weight and others small and non-conjugative.

1982 - R factors in group D streptococci: Classification by compatibility [Articolo su rivista]
Messi, P.; Bondi, Moreno; Borghi, V.; Piccinini, L.; Manicardi, G.
abstract

Università degli studi di Modena e Reggio Emilia

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