Evaluation of two commercial real-time PCR assays for detecting campylobacter in broiler carcass rinses

• Published in: Journal of food safety 2010-08, Vol.30 (3), p.732-739
• Main Authors: Englen, Mark D, Berrang, Mark E, Meinersmann, Richard J, Fedorka-Cray, Paula J
• Format: Article
• Language: English
• Subjects: Assaying; bacterial contamination; Bioassays; Biological and medical sciences; broiler carcass rinses; broiler chickens; Broths; Campylobacter; carcass evaluation; carcass quality; Carcasses; chicken carcasses; Comparative analysis; equipment performance; Food industries; Food products; Food safety; Foods; Fundamental and applied biological sciences. Psychology; General aspects; Gram-negative bacteria; Hygiene and safety; Meat and meat product industries; microbial detection; microbiological risk assessment; Plating; Polymerase chain reaction; Poultry; Real time; real time polymerase chain reaction; washing
• ISSN: 0149-6085; 1745-4565
• DOI: 10.1111/j.1745-4565.2010.00237.x

Traditional plating methods are reliable means for Campylobacter identification from poultry samples but automated gene-based detection systems now available can reduce assay time, data collection and analysis. Bio-Rad and DuPont Qualicon recently introduced Campylobacter assays for their real-time polymerase chain reaction (PCR) instruments. We evaluated the utility of these assays compared with standard plating and enumeration methods routinely used in our laboratory. Two replicates of 40 broiler carcass rinses collected before and after defeathering at a commercial processing plant were tested. All samples were positive for Campylobacter by direct plating of rinses: log₁₀ cfu values ranged from 0.24 to 4.61. In contrast, the Bio-Rad iQ-Check assay returned 60-72.5% positives on direct rinses; the Qualicon BAX Q7 test produced 60-85% positives with direct rinse samples. Using aliquots of 24 h enrichment broth from rinses in the real-time assays significantly improved detection: the Bio-Rad test had 95-100% positive while the Qualicon assay found 90-95% positive. Traditional detection methods for Campylobacter are time-consuming, requiring as much as 5 days to complete. The recent introduction of commercial real-time PCR instruments for the identification of Campylobacter offer more rapid, simplified alternatives to standard culture-based techniques.