Enumeration of Salmonella and Campylobacter spp. in Environmental Farm Samples and Processing Plant Carcass Rinses from Commercial Broiler Chicken Flocks

Abstract

ABSTRACTA prospective cohort study was performed to evaluate the prevalences and loads ofSalmonellaandCampylobacterspp. in farm and processing plant samples collected from 55 commercial broiler chicken flocks. Environmental samples were collected from broiler houses within 48 h before slaughter, and carcass rinses were performed on birds from the same flocks at 4 different stages of processing.Salmonellawas detected in farm samples of 50 (90.9%) flocks and in processing samples of 52 (94.5%) flocks.Campylobacterwas detected in farm samples of 35 (63.6%) flocks and in processing samples of 48 (87.3%) flocks. There was a significant positive relationship between environmental farm samples and processing plant carcass rinses with respect to bothSalmonellaandCampylobacterprevalences and loads.Campylobacterloads were significantly higher thanSalmonellaloads, and the correlations between samples collected from the same flocks were higher forCampylobacterthan they were forSalmonella. Boot socks were the most sensitive sample type for detection ofSalmonellaon the farm, whereas litter samples had the strongest association withSalmonellaloads in pre- and postchill carcass rinses. Boot socks, drag swabs, and fecal samples all had similar sensitivities for detectingCampylobacteron the farm, and all were more strongly associated withCampylobacterloads in carcass rinses than were litter samples. Farm samples explained a greater proportion of the variability in carcass rinse prevalences and loads forCampylobacterthan they did forSalmonella. SalmonellaandCampylobacterprevalences and loads both decreased significantly as birds progressed through the processing plant.