Introduction: The study objective was to develop and evaluate a new TaqMan multiplex real-time PCR method for Salmonella, L. monocytogenes, and verotoxigenic Escherichia coli (VTEC) detection in slaughtered animal carcasses.

Introduction: The study objective was to develop and evaluate a new TaqMan multiplex real-time PCR method for Salmonella, L. monocytogenes, and verotoxigenic Escherichia coli (VTEC) detection in slaughtered animal carcasses.Material and Methods: The procedure included an enrichment step, DNA extraction, and two multiplex real-time PCRs. The first PCR detected the invA and hly genes of Salmonella and L. monocytogenes respectively, the second the vtx1, vtx2, and eae genes of VTEC.Results: The validation of this method resulted in 100% relative sensitivity, specificity, and accuracy as compared to the reference ISO methods. The limit of detection per swab sample was established at 1 cfu for Salmonella and L. monocytogenes and 2 cfu for VTEC. The authors analysed 265 slaughterhouse-collected swabs from cattle, pig, and poultry carcasses. Among 125 from cattle, 51 were positive for VTEC, 29 for Salmonella, and 1 for L. monocytogenes. Among swabs from pig carcasses (n = 95), three, two, and one sample were positive for these pathogens respectively. None of the microorganisms tested for was identified in 45 samples of poultry origin.Conclusion: The obtained results showed that the method developed can rapidly identify the main bacterial pathogens that may contaminate carcasses of food-producing animals.

This study was conducted to investigate whether dietary enzymes alter the caecal microbial profile of broilers fed sorghum-based diets. Four sorghum-based diets (918 g sorghum/kg diet) were prepared. One was the control diet and three had enzymes (xylanase, phytase andprotease) added. Broilers, 35-day-old, were reared (8 birds/cage) in an environmentally controlled shed and randomly allocated to replicated (n=4) assay diets and free access to feed and water all time. On day-42, birds were euthanized and caecal contents collected, pooled on a per/pen basis and frozen (-20 °C). The DNA was extracted from caecal samples using a bead-beating protocol and the V2V3 regionof the bacterial 16S rRNA gene amplified by PCR. Amplicons were separated on sequence difference using Denaturing Gradient Gel Electrophoresis (DGGE) and microbial profiles generated and compared.The DGGE profiles, when analysed, indicated that there was approximately 80% similarity between caecal microflora in all types of the diet treatments. This suggests that there was no overalldifference between any of the profiles and therefore the addition of different types of feed enzymes in a sorghum-based diet had no impact on the overall composition of the broiler caecal microflora.