Comparison of Campylobacter populations isolated from a free-range broiler flock before and after slaughter

Abstract

Relatively little is known about the Campylobacter genotypes colonizing extensively reared broiler flocks and their survival through the slaughter process, despite the increasing demand for free-range and organic products by the consumer. Campylobacter isolates from a free-range boiler flock, sampled before and after slaughter, were genotyped by MLST (multilocus sequence typing) and sequence analysis of the flaA short variable region (SVR). The Campylobacter genotypes isolated before and after slaughter were diverse, with up to five sequence types (STs) (seven-locus allelic profiles resulting from MLST) identified per live bird, up to eight STs identified per carcass and 31 STs identified in all. The majority (72.0%) of isolates sampled from carcasses postslaughter were indistinguishable from those isolated from the live flock before slaughter by ST and flaA SVR type, however, sampling 'on-farm' failed to capture all of the diversity seen postslaughter. There were statistically significant increases in the genetic diversity of Campylobacter (p=0.005) and the proportion of C. coli (p=0.002), with some evidence for differential survival of genotypes contaminating the end product. C. coli genotypes isolated after slaughter were more similar to those from free-range and organic meat products sampled nationally, than from the live flock sampled previously. This study demonstrated the utility of MLST in detecting genetic diversity before and after the slaughter process.

Duck Liver–associated Outbreak of Campylobacteriosis among Humans, United Kingdom, 2011

“…The presence of multiple Campylobacter strains ( 6 ) in individual outbreaks linked to chicken liver is consistent with documentation that chickens harbor multiple strains ( 8 ), that pâté is prepared from multiple livers ( 5 , 6 ), or both. We describe epidemiologic evidence for a duck liver pâté–associated outbreak and compare sequence types (STs) of isolates with animal and food isolate datasets.…”

Comparison of Genotypes and Antibiotic Resistances of Campylobacter jejuni and Campylobacter coli on Chicken Retail Meat and at Slaughter

“…This observation is supported by a recent study from the United Kingdom where the predominant strains in poultry flocks were also the predominant strains found on the final carcass (12), but it is in contrast to other studies where differential survival of genotypes was observed (13,14).…”

Genotype and Antibiotic Resistance Analyses of Campylobacter Isolates from Ceca and Carcasses of Slaughtered Broiler Flocks

“…Statistical analysis indicated that this is a highly significant association and that the majority of samples obtained from the neck skin originated from the slaughtered flock itself. Given the fact that only single colonies were analyzed and that both species and various genotypes can be present in the flock, the true number of self-contaminated carcasses can be quite large (5,52). The remaining nonmatching isolates that were obtained from the neck skin could have come from other contaminated sources, such as previously slaughtered batches, equipment, working surfaces, or water (19,36,49).…”