Comparison of weep and carcass rinses for recovery of Campylobacter from retail broiler carcasses

Abstract

Campylobacter is frequently recovered from broiler carcasses. Carcass rinsing is a commonly used procedure for isolating Campylobacter from poultry. A viscous fluid, or weep, exudes from broiler carcasses that have been packaged. This fluid can contain bacteria that were attached to the carcass and represents a potential means of detecting Campylobacter-contaminated carcasses through cultural analysis. Experiments were conducted to compare the efficacy of a weep sampling method with that of a carcass rinse method. For both trials, retail carcasses were purchased. Packages were opened, and 0.1-ml aliquots of weep fluid from the retail packages were plated onto Campy-cefex agar. Carcasses were removed from the package and rinsed in 100 ml of sterile water. Next, 0.1-ml aliquots of the rinsate were plated onto Campy-cefex agar and incubated. In a second experiment, samples were both directly plated and enriched in Bolton enrichment broth. In the first experiment, 35 of 60 carcass rinses tested positive for Campylobacter, while 29 of 60 weep samples yielded Campylobacter isolates with levels of 1.0 and 1.1 log CFU/ml, respectively. In the second experiment, Campylobacter was recovered from 9 of 40 rinse samples and from 13 of 40 weep samples by direct plating, while the organism was recovered from 28 of 40 rinses samples and from 23 of 40 carcass samples by enrichment. There was no significant difference between the two methods with respect to Campylobacter prevalence as determined by the chi-square test. Campylobacter levels recovered by both methods averaged 0.9 log CFU/ml. The sampling of weep fluid was a simple, effective means of detecting this important human enteropathogen on broiler carcasses.