|Line, John - Eric|
Submitted to: Journal of Food Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2004
Publication Date: 5/4/2004
Citation: Siragusa, G.R., Line, J.E., Brooks, L., Hutchinson, T., Laster, J., Apple, R.O. 2004. Serological methods and selective agars to enumerate Campylobacter from broiler carcasses: Data from inter- and intra laboratory analysis. Journal of Food Protection. 67:901-907. Interpretive Summary: We have systematically evaluated the utility of three Campylobacter serological confirmation assays used in conjunction with selective isolation media (Campy-Cefex and Campy-Line agars) for the presumptive estimation of Campylobacter levels in poultry rinses. Based on samples taken from broiler carcasses both before and after chlorinated chilling, our data indicate that for the high sample throughput lab, such as that associated with poultry processing outfits, the pre-measured and dried anti-Campylobacter latex agglutination reagent format (Dryspot Campylobacter test) was superior to liquid latex and a microscopic method for testing antibody reactivity. We also demonstrated that it was possible to obtain Campylobacter counts between labs that were statistically similar even when those counts were determined an entire day after the samples were taken. In summary, this work demonstrates selective agars were efficacious for enumerating Campylobacter levels and when used with subsequent serologic confirmation is a highly practical scheme for accomplishing this analysis in the high sample throughput lab.
Technical Abstract: Routine analytical means to estimate Campylobacter numbers per ml of carcass rinses is needed in high sample throughput poultry laboratories. In this study we compared three serological confirmatory tests that were amenable to such a setting when used in conjunction with Campy-Line and Campy-Cefex Campylobacter selective agars. Pre and post-chlorinated chiller carcass rinse samples were obtained and held on ice then analyzed 24 h later in two separate labs. Presumptive counts on both pre and post chiller samples from between labs on individual agars and between both agars were highly correlated. Agreement between the three serological tests was nearly complete. The use of a pre-measured and dried latex anti-Campylobacter antibody agglutination test format was superior to that of either liquid latex agglutination format or a direct FA microscopic technique in terms of practicality as well as the inclusion of an unarmed latex control to detect auto agglutination. A routine procedure for Campylobacter level estimation was suggested which when used in conjunction with a serologic confirmatory step should provide processors with a means to assess reductions in numbers per ml of carcass rinses vs. strictly presence absence testing.