Resistance to apramycin of Salmonella and E.coli isolated from swine

The aim of this study was to determine the prevalence of aminoglycosides antibiotic resistance in Salmonella spp. and E. coli strains. 32 E. coli, and 47 Salmonella spp., isolated from cases of enteritis in growers and fatteners from 1998 to 2002 in Umbria and Marche regions, were tested. Susceptibility to gentamicin, tobramycin and streptomycin was determined by Kirby-Bauer method, apramycin by microdilution method. 92,4 % of the strains tested were susceptible to apramycin, 77,2 % to gentamicin, 67,1 % to tobramycin and 35,4 % to streptomycin. A positive statistical association between gentamicin and apramycin (RR = 7,63; p = 0,014), tobramycin and apramycin (RR = 9,22; p = 0,027) was demonstrated. There is no difference between the association apramycin-streptomycin, suggesting a mechanism of resistance related to the presence of the aminoglycoside acetyltranspherase IV enzyme. The trend based on estimated OR from the resistance of the strains for every year considered was significant (p = 0,00049), showing a progressive decrease from 1998 (OR = 1) to 2002 (OR = 0,3)

ASPETTI COMPORTAMENTALI, PRESTAZIONI PRODUTTIVE E QUALITÀ DELL'UOVO IN GALLINE ALLEVATE CON IL METODO BIOLOGICO

The aim of this trial was to study the effect of organic housing system on the behaviour, productive performance and the qualitative characteristics of eggs. The experiment was conduced directly in the field on Hy-Line laying hens from the beginning of the productive period (17 weeks of age) till the end of productive career. The animals were divided in two homogeneous groups and assigned to the following housing system: control, conventional cage (18 bird/m2) and organic 6 birds m2 in a covered straw-bedded house with access to a paddock (4 m2/bird). A standard feed with the same nutritive characteristics was given ad libitum to the chickens. For the organic, more than 80% of the ingredients (maize, wheat and whole soybean) were organically grown, as established by Regulation 1804/99. Ethological parameters (first impact, tonic immobility and behavioural patterns) and the plumage conditions showed better welfare conditions in organic laying hens. The greater movement of those animals lowered productive performances (lighter and less eggs); on the contrary the higher welfare and the minor overexploitation of organic animals permitted a longer productive life. The microbiological safety of eggs showed low levels of mesophila bacteria even though the organic system increased their mean value. There were few enterobacteria (< 100 CFU) and Salmonella spp. not present in any of the eggs analysed

Bdellovibrio bacteriovorus to control Escherichia coli on meat matrices

Bdellovibrio bacteriovorus is a predator micro-organism towards other Gram-negative bacteria. We tested B.&nbsp;bacteriovorus to control Escherichia coli growth on chicken slices and canned beef. Moreover, we analysed B.&nbsp;bacteriovorus's lytic ability on eight toxigenic or multidrug-resistant E.&nbsp;coli strains. In chicken slices, the predator induced the highest prey reduction (4.3 log) respect to control at 6&nbsp;h. In canned beef, the predator induced the highest prey reduction (2.1 log) respect to control at 6&nbsp;h. Moreover, B.&nbsp;bacteriovorus showed lytic ability towards all tested E.&nbsp;coli strains. B.&nbsp;bacteriovorus could control E.&nbsp;coli and other pathogenic and spoilage bacteria in those meat-based foods that have a shelf life &lt;10&nbsp;days. It could integrate modified atmosphere packaging (MAP) to prolong the shelf life and improve the safety of pre-packed fresh meat, meat preparations and meat products. In future applications on meat-based foods, B.&nbsp;bacteriovorus could also minimise the use of additives

STUDY OF AN ARTIFICIAL VAGINA TO REDUCE THE MICROBIAL CONTAMINATION OF RABBIT SEMEN

[EN] Aim of the work was to evaluate and improve the efficiency of an artificial vagina with a short body which permits to collect semen almost directly into the test-tube (with the least contact with the elastic sheath). At the same time, also the test-tube is not in contact with the sheath. Ten adult hybrid bucks were collected during 10 weeks. The experiment consists of 2 successive phases: 1) analysis of microbial flora naturally present in the semen; 2) evaluation of effect of exogenous contamination. Each time, 2 collections were done, using alternatively the prototype and the standard vagina (as a control) at intervals of 20 minutes (maximum 5 times). Throughout the experiment data were collected, concerning operational activities (ejaculation time and reduced sheath temperature from 45 to 35 ºC), biological quality of semen (volume, sperms concentration, live sperms) and microbial contamination rate (specific and total flora). The results showed that the time employed to collect the semen was not significantly affected by the different models of artificial vagina used. The microbial contamination of the semen collected with the prototype was lower than the other (phase a, b). The number of collections done using the same vagina did not affect biological characteristics of semen whereas increased progressively the microbiological contamination. A reduction of the contamination at the least 40% can be realized when the prototype is used (phase b).[FR] Le but de ce travai/ est d'évaluer et d'améliorer l'efflcacité d'un vagin artificiel assez court pour permettre la collecte presque directe dans le tube 8 essai de la semence (avec le moins de contact possible avec la gaine élastique). De plus le tube 8 essai lui-mfJme n'est pas en contact avec la gaine. Des récoltes ont été effectuées sur 10 máles adultes hybrides pendant 10 semaines. L'expérience comporte deux phases successives : 11 analyse de la flore microbienne naturelle contenu dans la semence. 21 évaluation de /'effet d'une contamination exogéne. A chaque prélévement deux récoltes ont été effectuées, en utilisant altemativement le prototype et le vagin artificiel standard (controle) a 20 minutes d'intervalles (5 fois maximum). Pendant /'expérimentation les données concemant les conditions opérationnelles (durée de /'éjaculation, température de la gaine allant de 45 a 35ºC) la qualité biologique du sperme (volume, concentration du sperme, vie des spermatozordes) et le taux de contamination microbienne (spécifique et flore totale) ont été enregistrées. Les résultats montrent que le temps consacré a la collecte n'est pas significativement différent que/que soit le type de vagin utilisé. La contamination microbienne de la semence collectée avec le vagin prototype est plus faible qu'avec le vagin standard (phase a, b). Le nombre de collectes effectuées avec le mfJme vagin n'affecte pas les caractéristiques biologiques de la semence bien que la contamination microbienne augmente progressivement. Une réduction de la contamination d'au moins 40 % peut fJtre obtenu en utilisant le vagin prototype (phase b).Research partly supported by MURST 60%Dal Bosco, A.; Scuota, S.; Castellini, C.; Cenci, T. (1996). STUDY OF AN ARTIFICIAL VAGINA TO REDUCE THE MICROBIAL CONTAMINATION OF RABBIT SEMEN. World Rabbit Science. 04(4). doi:10.4995/wrs.1996.295SWORD04

ANOMALOUS BLUE COLOURING OF MOZZARELLA CHEESE INTENTIONALLY CONTAMINATED WITH PIGMENT PRODUCING STRAINS OF PSEUDOMONAS FLUORESCENS

In summer 2010 a large outbreak of anomalous blue coloration of mozzarella cheese was recorded in Italy and some northern European countries. Official laboratory analysis and health authorities linked the outbreak to the contamination of processing water with strains of Pseudomonas fluorescens, although several expert raised the question of how to unequivocally link the blue coloring to the presence of the micro-organism. In an attempt to set-up a method to determine whether a given Pseudomonas spp. strain is responsible of the defect, an in vitro system for the evaluation of blue colouring of mozzarella cheese intentionally contaminated with strains of Pseudomonas fluorescens. was developed The system is aimed to ascertain whether P. fluorescens strains, isolated from mozzarella cheese with anomalous blue coloration, are able to reproduce the blue coloration under controlled experimental condition. 96 trials of experimental inoculation of mozzarella cheese in different preservation liquids, were conducted using various suspension of Pseudomonas spp. (P. fluorescens ATCC 13525, P. fluorescens CFBP 3150, one P. fluorescens field strain isolated from blue-colored mozzarella cheese and P. aeruginosa ATCC 10145 as positive control) at different concentrations and incubated at different temperatures. Growth curve of all Pseudomonas spp. strains tested demonstrated that after three days of incubation the concentration was generally higher than 106 CFU/g of mozzarella cheese incubated in Tryptic Soy Broth (TSB), and higher than 105 CFU/g of mozzarella cheese incubated in preservation liquid. All mozzarella cheeses inoculated with the field strain of Pseudomonas fluorescens showed the characteristic anomalous blue coloration, which is often associated with Pseudomonas fluorescens contamination of water used during mozzarella cheesemaking. With the proposed system, which enabled a considerable amount of samples to be analysed under controlled experimental conditions and a large number of data to be generated in a short time, we demonstrated that the presence of Pseudomonas fluorescens in blue coloured mozzarella cheese is a necessary and sufficient condition

Resistance to apramycin of Salmonella and E.coli isolated from swine

The aim of this study was to determine the prevalence of aminoglycosides antibiotic resistance in Salmonella spp. and E. coli strains. 32 E. coli, and 47 Salmonella spp., isolated from cases of enteritis in growers and fatteners from 1998 to 2002 in Umbria and Marche regions, were tested. Susceptibility to gentamicin, tobramycin and streptomycin was determined by Kirby-Bauer method, apramycin by microdilution method. 92,4 % of the strains tested were susceptible to apramycin, 77,2 % to gentamicin, 67,1 % to tobramycin and 35,4 % to streptomycin. A positive statistical association between gentamicin and apramycin (RR = 7,63; p = 0,014), tobramycin and apramycin (RR = 9,22; p = 0,027) was demonstrated. There is no difference between the association apramycin-streptomycin, suggesting a mechanism of resistance related to the presence of the aminoglycoside acetyltranspherase IV enzyme. The trend based on estimated OR from the resistance of the strains for every year considered was significant (p = 0,00049), showing a progressive decrease from 1998 (OR = 1) to 2002 (OR = 0,3).</p

“Applicazione di un metodo biomolecolare per la ricerca rapida di Yersinia enterocolitica patogena in carcasse di suini regolarmente macellati”

A multiplex PCR method for simultaneous detection of Yersinia enterocolitica and ail gene has been applied on samples from slaughtered pig carcasses. The method was effective, fast and simple, capable of detecting pathogenic Yersinia enterocolitica in 48-72 hours. It offers significant advantages over the microbiological methods of isolation, allowing shorter response times and early detection of strains carrying the pathogenicity factor

ANALYTICAL INVESTIGATIONS DURING A HACCP PROGRAMME APPLIED TO SCHOOL CATERING OF THE PERUGIA MUNICIPALITY: YEARS 2008-2010

This paper reports the results obtained during the analyses performed to evaluate the correct implementation of an HACCP plan in the school catering services of Perugia operating with the Istituto Zooprofilattico Sperimentale dell&rsquo;Umbria e delle Marche (IZSUM). The microbiological analyses concern the years 2008-2010 for a total of 4050 determination relative to 79 facilities. The analytical results show the risks are kept at an acceptable level in all the canteens sampled. In the time period considered no foodborne diseases were reported

Salmonella enterica adhesion: Effect of Cinnamomum zeylanicum essential oil on lettuce

Salmonella is a foodborne pathogen able to adhere and persist on biotic and abiotic surfaces, including vegetables, which are even more linked to foodborne outbreaks. In this work, first we investigated the capability of Salmonella to adhere on different surfaces (stainless steel, polypropylene and lettuce), then we evaluated the potential effect of essential oils in reducing the adhesion and persistence of the pathogen on lettuce. Eight essential oils (EO)were tested on five Salmonella enterica strains (serovars Derby, Thompson, Napoli, Kasenyi and Veneziana). Cinnamomum zeylanicum EO (CEO)was the most effective, according to Minimal Inhibitory Concentration (MIC 1.25–1.87 μL/mL)and to growth/inhibition dynamics. To simulate real conditions, a cocktail of Salmonella Kasenyi, S. Veneziana and S. Napoli was applied on the three surfaces, but it adhered only on lettuce, starting from 1 h of contact (4.59 ± 0.34 Log UFC/cm 2 ). Five μL/mL CEO, applied on lettuce, immediately reduced the loosely and strongly attached cells (reduction of 0.78 Log and 0.63 Log CFU/cm 2 , respectively), with significant effect up to 120 h. CEO also inhibited the Polyphenol Oxidase activity, thus preserving lettuce colour during storage. Cinnamon EO could therefore help to improve safety and appearance of fresh-cut lettuce during storage