MOLECULAR CHARACTERIZATION AND GASTROINTESTINAL TRACT ECOLOGY OF COMMENSAL HUMAN FOOD-BORNE BACTERIAL PATHOGENS IN THE CHICKEN
Location: Poultry Microbiological Safety Research
Title: Carcass enrichment detects Salmonella from broiler carcasses found to be negative by other sampling methods
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2010
Publication Date: January 24, 2011
Citation: Cox Jr, N.A., Buhr, R.J., Cray, P.J., Cason Jr, J.A., Cosby, D.E., Rigsby, L.L., Bourassa, D.V. 2011. Carcass enrichment detects Salmonella from broiler carcasses found to be negative by other sampling methods. International Poultry Scientific Forum. 259P, P.75 (ABST)..
The most frequently used methods to recover Salmonella from processed broiler chicken carcasses involve carcass rinsing or neck skin maceration. These methods are nondestructive and practical, but have limited sensitivity. The standard carcass rinse method uses only 7.5% of the residual rinsate and the standard neck skin method samples approximately 4% of the skin by weight. Should it be necessary to detect the presence of low numbers or firmly attached Salmonella, the rinse and neck skin methods may result in many false negatives. The objective of this study was to compare the sensitivity of a carcass enrichment method to the most commonly used procedures in the United States (rinse) and the European Union (neck skin) for the detection of naturally occurring Salmonella on broiler carcasses. In the first experiment, 80 broilers grown for 6 wk on Salmonella-contaminated litter were processed and rinsed with 400 mL of 1% buffered peptone water. After 30 mL were removed and incubated separately, the remaining rinsate and carcass were incubated together at 37oC for 24 h. The carcass rinse method recovered Salmonella from 7/80 (8.8%) while the carcass enrichment procedure detected Salmonella on 24/80 (30%). In a second experiment broiler carcasses were obtained from a commercial processing plant and each carcass was sampled by three methods (carcass rinse, neck skin, carcass enrichment). From the 40 carcasses analyzed by three methods, Salmonella were detected on 10, 17 and 39 from the carcass rinse, neck skin, and carcass enrichment, respectively. Only one Salmonella serogroup was isolated from the carcass rinse method (C3), two from the neck skin (B, C2) and five from the carcass enrichment (B, C2, C3, D, E). Carcass enrichment finds more Salmonella-positive carcasses and a greater number of serotypes.