Purpose: In this study, we intended to apprehend the Campylobacter contamination level in chicken carcasses from slaughterhouses and to discern which step of slaughtering process is mainly causing the contamination, in order to develop a plan for control of this pathogen.
Methods: Samples were taken from eight chicken slaughterhouses in 2012. Among the total 1150 samples, 1090 samples were collected from two chicken slaughterhouses continually for five months from four sites of slaughtering process. Samples were collected from; 1) anus swab in live bird that was waiting to enter the slaughter line; 2) carcass after removal of intestine; 3) carcass after washing the interior and exterior, and 4) final carcass. Detection and quantification tests were done according to USDA microbial laboratory guidelines. In addition, multiplex PCR was used to identify the colonies as Campylobacter jejuni, C. coli and C. lari. To quantify the colonies, samples were directly spread onto campy-cefex agar. The genetic relationships between the isolates were analyzed by Rep-PCR.
Results: 118 samples were positive for Campylobacter spp. (10.3%). The prevalence of C. jejuni, C. lari and C. coli was 6.1%, 2.4% and 3.0%, respectively. Forty-one percent of total isolates were from the carcass after removal of intestine, and 32.2% of those isolates were more than 103 CFU/ml. The genetic homology of the isolates from the same slaughterhouse was approximately 80%.
Significance: Contamination rate of Campylobacter spp. in final carcasses shows low levels compared to that of other countries. Among the samples, carcasses after removal of intestines had the highest contamination rate. To lower the contamination rate further, it is suggested that the process of removal of intestine needs to be performed without rupture and sufficient washing step must be maintained.