Detection of Salmonella Serotypes by Overnight Incubation of Entire Broiler Carcass

Abstract

AbstractThere are multiple ways to sample broiler chicken carcasses for the prevalence of Salmonella. A common method in the USA is a whole carcass rinse and culture of an aliquot of the rinse. The objective of this study was to compare the sensitivity of the rinse aliquot method to overnight enrichment of the entire carcass in the rinse liquid. Fourteen replicate samplings of eight carcasses each were done at two commercial broiler processing plants. Carcasses were subjected to a whole carcass rinse in buffered peptone from which 30 mL was removed and added to 30 mL fresh buffered peptone (rinse aliquot sample). The aliquot sample and the carcass, in the remaining buffered peptone, were incubated overnight prior to standard selective enrichment and plating for Salmonella detection. Salmonella was detected in 15% of rinse aliquot samples and 59% of whole carcass enrichment samples. When detected by both methods, for the most part, the same serotypes were found on individual carcasses. Whole carcass enrichment was shown to be more sensitive than rinse aliquot method, and likely detects Salmonellae even when tightly bound to the carcass or present in very low numbers. As such, whole carcass enrichment is a useful research tool to determine Salmonella prevalence.Practical ApplicationsWhole broiler carcass enrichment is a more sensitive method for detection of Salmonella than whole carcass rinse and aliquot incubation. Logistical requirements, however, make it impractical for routine or large scale investigations. Whole carcass enrichment has utility for research purposes to determine relative sensitivity of other methods or for testing of broiler processing microbial interventions.