Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2008
Publication Date: 11/20/2009
Citation: Debretsion, A., Habtemariam, T., Wilson, S., Wesley, I.V., Yehualashet, T. 2009. Comparative Assessment of Standard Culture and Real-Time PCR to Detect Campylobacter jejuni in Retail Chicken Samples. Journal of Food Safety. 29(4):588-600. Interpretive Summary: Campylobacter is the major cause of bacterial gastroenteritis with consumption of contaminated poultry recognized as a major risk factor. We screened retail poultry carcasses for Campylobacter using a newly developed real-time PCR (rtPCR) assay and compared it to routine bacteriology. The sensitivity of the rt PCR when compared to conventional culture as the reference standard (100% sensitivity) was 81%. However, the rtPCR assay with a detection limit of 1 CFU/ml can be completed in less than three hours from sampling to final detection of C. jejuni whereas conventional culture methods require three to five days. Application of a rapid and sensitive rtPCR for detection and enumeration of C. jejuni is important for the maintenance of a safe poultry supply.
Technical Abstract: Contamination of poultry by Campylobacter is a significant source of human diarrheal illness. Conventional bacteriological methods to detect and speciate Campylobacter jejuni (C. jejuni) from chicken samples are labor-intensive and time-consuming. The purpose of this study was to compare standard culture-based methods and real-time PCR (rtPCR) for detection of C. jejuni from retail chicken samples. Culture methods (modified Campy-Cefex Agar, Charcoal cefoperazone deoxycholate agar and Brucella broth) were compared with real-time PCR (rtPCR without enrichment) for detection of C. jejuni in naturally contaminated chicken samples. Retail purchased chicken samples (n=43) were collected from four supermarkets. C. jejuni was detected by Direct Plating to Selective Agar (5/43, 11.6% DPSA), rtPCR (15/43, 34.9%), and Bolton’s enrichment (8/43, 41.9%, BE). Fifteen chicken samples were concordant by rtPCR and BE whereas three samples were positive only by BE. The sensitivity of the real-time PCR and DPSA, when compared to BE as the reference standard (100% sensitivity) were 81% and 29%, respectively. However, the rtPCR assay with a detection limit of 1 CFU/ml can be completed in less than three hours from sampling to final detection of C. jejuni. In contrast, conventional culture methods (BE and DSPA) require three to five days to speciate C. jejuni. Application of a rapid and sensitive rtPCR for detection and enumeration of C. jejuni is important for the maintenance of a safe poultry supply.