Quantification of Campylobacter spp. in chicken carcass rinse by real-time PCR

In this study, a real-time quantitative polymerase chain reaction (PCR) method was examined for its ability to quantify Campylobacter spp. in chicken carcass rinses and compared with bacteriological culturing. The linearity of the real-time PCR quantification protocol was assessed on pure DNA. The amplification efficiency was 100% and the square regression coefficient (R-2) was 0.998. Quantification was linear over at least 7 log units. Using a crude cell lysate gave the highest sensitivity and the detection limit of the method was 3.3 log CFU per carcass. The statistical correlation between the bacteriological enumeration and the real-time quantitative (Q)-PCR determined using chicken carcasses sampled at the end of the slaughter line was 0.733. The difference in detection levels was probably because of the detection of stressed, dead or viable but not culturable cells by Q-PCR. The real-time Q-PCR method described in this study is a powerful tool for determining the number of Campylobacter cells on carcasses. The real-time Q-PCR method is available to quantify the Campylobacter contamination at the slaughterhouse level and could be used to evaluate primary production.