Evaluation of TECRA® broth, Bolton broth and direct plating for recovery of Campylobacter spp, from broiler carcass rinsates from several commercial processing plants

Authors: Richardson, Larry; Cox Jr, Nelson; Bailey, Joseph; Berrang, Mark; COX, J - NEW SOUTH WHALES; Buhr, Richard - Jeff; Cray, Paula; HARRISON, M - UGA

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2008
Publication Date: 5/1/2009
Citation: Richardson, L.J., Cox Jr, N.A., Bailey, J.S., Berrang, M.E., Cox, J.M., Buhr, R.J., Cray, P.J., Harrison, M.A. 2009. Evaluation of TECRA® broth, Bolton broth and direct plating for recovery of Campylobacter spp, from broiler carcass rinsates from several commercial processing plants. Journal of Food Protection. 72(5):972-977.

Interpretive Summary: Campylobacter spp. are a major cause of human bacterial gastroenteritis in the U.S. However, there is no universally accepted standard Campylobacter spp. recovery method for food samples. The aim of the current study was to evaluate a conventional and newly developed selective enrichment broth along with direct plating for Campylobacter recovery from chicken carcass rinses obtained from several commercial poultry processing plants. The newly developed selective enrichment broth (TECRA® broth) was more sensitive than the conventional broth (Bolton broth) for Campylobacter spp. recovery from carcass rinses but analysis of both enrichment procedures combined allowed for the best sensitivity. Direct plating allowed for the evaluation of the processing steps on reducing the level of Campylobacter spp. on chicken carcasses but severely underestimated the incidence rate of Campylobacter spp. on carcasses after the chilling process. A more sensitive recovery method for Campylobacter spp. was obtained and the findings provided insight into the sensitivity of certain Campylobacter cultural procedures to recover low levels of injured or stressed Campylobacter cells from chicken carcasses.

Technical Abstract: The purpose of this study was to compare a conventional culture broth method (Bolton enrichment broth containing lysed horse blood), a newly developed proprietary broth method (TECRA® Campylobacter enrichment) and direct plating for Campylobacter spp. recovery from chicken carcass rinses. Whole carcass rinses were taken from 140 carcasses at rehang (immediately after defeathering but before evisceration) and 140 carcasses at post-chill from 8 different processing lines in the United States. The samples were ice packed and shipped overnight to the laboratory. An aliquot of the sample rinse was transferred into Bolton and TECRA® enrichment broths and also direct plated. Standard laboratory procedures using Campy-cefex plates were followed for recovery of Campylobacter spp. For rehang carcass rinse samples, 86% of samples were positive for Campylobacter spp. from TECRA® enrichment broth and 74% from Bolton enrichment broth. For post-chill carcass rinse samples, 74% of samples were positive for Campylobacter spp. from TECRA® enrichment broth and 71% from Bolton enrichment broth. Evaluation of non-Campylobacter colonies on Campy-cefex plates revealed that TECRA® enrichment broth significantly suppressed the competing organisms when compared to Bolton enrichment broth. Overall, TECRA® enrichment broth yielded a 7.5% increase in the total number of positive samples compared to Bolton enrichment broth. Campylobacter spp. detection in post-chill samples was significantly greater employing enrichment than direct plating. Direct plating only detected 19% of the samples positive. Analysis of Campylobacter-positive samples by both enrichment procedures revealed that 90% of the carcass rinses obtained at rehang and 87% at post-chill contained Campylobacter spp.