IAFP 2009 Program Book and Abstract Book - AB70

was observed on roast beef without SL/SD and stored at 12°C. Overall, the fate of total microbial populations was similar to that of L. monocytogenes. Significance: These data should be useful in reduction of uncertainties in predictive models used in developing or updating quantitative risk assessments of L. monocytogenes in Ready-to-Eat meats. P1-24 Microwell Format Detection Method for Campylobacter spp. in Foods Using DNA Hybridization PAUL NORTON, Aarti Gupta, Sugathri Velmineti and Mark Mozola Neogen Corporation, Molecular Biology R&D, Lansing, MI, USA Introduction: A microwell format DNA hybridization assay has been developed that employs DNA probes specific to Campylobacter spp. ribosomal RNA sequences in a solution phase hybridization, with detection by means of an enzymatically generated colorimetric endpoint. Purpose: The GeneQuence Campylobacter assay is a DNA hybridization method for the detection of Campylobacter spp. in food samples. The assay has been validated for whole chicken carcasses, and application of the assay to other sample types is currently being developed. Methods: For the currently validated method, Campylobacter recovery was achieved by chicken carcass rinse in 200 ml buffered peptone water. A one milliliter sample was taken from the rinse and enriched for 4 h at 37°C in supplemented Hunt broth under microaerophilic conditions (5% O2, 10% CO2, 85% N2). Cefoperazone was then added for Campylobacter selectivity and incubation was continued at 42°C for 20 h. Campy-Cefex agar plates were then swabbed with the broth and incubated at 42°C for 24 h. Growth was collected from the Campy-Cefex plate into one milliliter buffered peptone water for analysis. Enrichments were treated with lysis reagent and rRNA targets were captured by means of DNA sandwich hybridization in microwell plates. Hybridization required one hour at room temperature and because of the uniqueness of the target sequence, it required no additional specificity control. Following hybridization, the plates were washed and enzyme substrate was added. The presence of Campylobacter spp. was indicated by enzymatic activity resulting in the development of blue color. Sulphuric acid was added to stop the reaction. Results were then obtained by measuring absorbance at 450 nm. Results: Sensitivity of 1000 CFU per chicken carcass has been demonstrated for the assay by analysis of spiked rinses, with inoculation levels determined by MPN. The method may be adapted for lower tolerance limits by adjusting the amount of rinse sampled for enrichment. The assay has been shown to be fully inclusive for C. coli (13 strains), C. jejuni (34 strains), and C. lari (5 strains), and fully exclusive for closely related non-Campylobacter species and other potentially encountered poultry microflora (30 strains across 14 genera). Significance: The development of this assay is applicable to food industry testing of commodities for contamination by Campylobacter spp. P1-25 Campylobacter jejuni Detection in Chicken Grow-out Houses by Environmental Sampling Methods DSC THOMAS KUNTZ, Joseph Eifert, Monica Ponder and David Schmale Virginia Tech, Food Science and Technology, Blacksburg, VA, USA Introduction: Campylobacter and Salmonella are foodborne pathogens commonly associated with raw poultry. Although there has been much research done on isolating these pathogens from the poultry production environment using cloacal swabs, fecal samples, and intestinal tract dissection, there has been less research involving environmental sampling. The use of PCR to analyze environmental samples would minimize the need for organism specific media while also detecting any Campylobacter or Salmonella that may be injured. Purpose: Improved environmental sampling methods provide an easy, convenient, and less time-consuming way to sample the poultry house environment for pathogenic organisms. Coupling this with PCR analysis can provide a relatively simple, rapid, and accurate way to test for these pathogens in a chicken house or flock prior to slaughter. Methods: Air, boot, and sponge samples were collected from three commercial chicken grow-out houses when flocks were three, four, and five weeks old. Air samples were collected onto gelatin filters. Fecal/litter samples were collected from disposable booties. Pre-moistened sponges were used to sample feedpans and drink lines. A PCR method was used to qualitatively detect Campylobacter jejuni and Salmonella spp., simultaneously, in each sample. Results: Campylobacter jejuni positive samples were found at each farm (house), at age three, four, and five weeks, and from each sample type. For all 270 samples, 110 (41%) were positive for Campylobacter and 0% for Salmonella. Collectively, 28% of air, 44% of sponge, and 50% of bootie samples were positive for Campylobacter. Significance: Environmental sampling as a pre-slaughter test for foodborne pathogens attributed to poultry deserves further investigations. The methods used in this study are non-invasive to live animals, relatively rapid and specific, and could enable poultry processing facilities to coordinate scheduled processing of flocks with lower pathogen incidence, as a way to reduce post-slaughter pathogen transmission. P1-26 Occurrence of Campylobacter spp. in Beef Carcasses and in Retail Chicken Cuts in São Paulo, Brazil Graciela Lopes, Eb Chiarini, Mariza Landgraf, Bernadette Franco and MARIA TERESA DESTRO University of São Paulo, São Paulo, Brazil Introduction: Campylobacter spp. is a relevant foodborne bacterial pathogen linked to undercooked meat consumption. Slaughtering operations have been determined as the main source of meat contamination by thermophilic Campylobacter species. In addition, the pathogen has been found to survive during chilled storage of meats. Purpose: The aim of this study was to evaluate the prevalence and population of thermophilic Campylobacter species (C. jejuni, C. coli and C. lari) in beef carcasses and chicken cuts obtained from a Brazilian slaughterhouse and retail, respectively. Poster 70 — Abstract Book

IAFP 2009 Program Book and Abstract Book

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