Recovery of salmonella from retail broilers by a whole-carcass enrichment procedure

Abstract

Fresh whole broiler carcasses were purchased from grocery stores over a 20-week period. Carcasses were selected on the basis of their having intact packages and unique U.S. Department of Agriculture (USDA) plant numbers and sell-by dates, such that each bird represented a single processing plant-processing day combination. Carcasses were tested for Salmonella with a rinse aliquot obtained after whole-bird incubation in the rinse media for 24 h. On the basis of the number of unique processing plants (USDA plant numbers) and expiration dates involved, the number of birds available each week ranged from 6 to 17. Over the 20-week period, 251 independent carcasses from 14 processing plants were tested. The percentages of carcasses testing positive for Salmonella ranged from 0 (for 1 week) to >60% (for 3 weeks). For only 4 of the 20 weeks was an incidence of Salmonella-positive carcasses of <20% found. For the entire 20-week study, 85 (33.9%) of the 251 carcasses tested were found to be Salmonella positive. For those processing plants from which >10 carcasses were obtained, the percentages of carcasses testing positive for Salmonella ranged from <20 (two plants) to >40% (four plants). These results indicate that a whole-carcass enrichment may be more sensitive for the detection of Salmonella-positive carcasses than the traditional whole-carcass rinse followed by immediate testing of a subsample aliquot when small numbers of Salmonella are expected.