Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2019
Publication Date: 7/10/2019
Citation: Berrang, M.E., Meinersmann, R.J., Cox Jr, N.A. 2019. Campylobacter subtypes detected in broiler ceca and livers collected at slaughter. Poultry Science. https://doi.org/10.3382/ps/pez340.
Interpretive Summary: There have been multiple outbreaks of foodborne campylobacteriosis caused by undercooked chicken liver dishes. We know that Campylobacter can be found in chicken livers at retail but we do not know what the prevalence is at slaughter. This project was designed to answer that question. We collected liver and gut from commercially slaughtered chicken carcasses, cultured Campylobacter from both samples and subjected the isolates to whole genome DNA sequence based subtyping. We tested 70 broiler carcasses, each from a unique flock, over the course of 12 months. We detected Campylobacter in at least one sample from 58 of 70 (83%) carcasses/flocks; 41 ceca, 57 liver surface samples and 19 liver internal tissue samples were positive. In some carcasses, the Campylobacter detected in liver and ceca were identical. In others, different subtypes were found. In seven carcases/flocks one subtype of Campylobacter predominated on the surface of the liver and a different subtype predominated inside the liver. Livers from a large percentage of broiler carcasses/flocks can have multiple subtypes of Campylobacter within minutes of evisceration. This information can be used to design effective intervention strategies to be employed at broiler slaughter plants to lessen Campylobacter contamination of chicken livers.
Technical Abstract: Foodborne campylobacteriosis has been linked to under cooked chicken liver. We have detected Campylobacter in chicken livers available for sale at retail. The objective of the current project was to determine the prevalence and subtype of Campylobacter associated with livers and ceca of broiler carcasses at commercial slaughter. Within 120 s of commercial evisceration, we collected liver and ceca of one broiler carcass from each of 70 discreet flocks over a 12-month period. Liver surface, liver internal tissue and cecal contents were cultured for Campylobacter using standard methods. One example of the predominant colony type was selected from each positive sample for whole genome sequencing and multilocus sequence typing. We detected Campylobacter in at least one sample from 58 of 70 (83%) carcasses/flocks; 41 ceca, 57 liver surface samples and 19 liver internal tissue samples were positive. For 11 of 18 carcasses from which all samples were positive, the predominant colony types were indistinguishable. However, some carcasses did have multiple subtypes of Campylobacter. Of carcasses with Campylobacter on the surface of the liver and within the ceca, it was more likely that the subtypes be the same than different (P<0.01). However, Campylobacter subtypes detected in internal liver tissue were not more likely to be the same as those detected in ceca (P>0.05). We detected different subtypes of Campylobacter from internal liver tissue and liver surface of seven broiler carcasses/flocks. Livers from a large percentage of broiler carcasses/flocks can have multiple subtypes of Campylobacter within minutes of evisceration.