ARS | Publication request: A Comparison of Methods for the Speciation of Campylobacter

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2007
Publication Date: December 17, 2007
Citation: Cray, P.J., Plumblee, J., Englen, M.D. 2007. A comparison of methods for the speciation of campylobacter. 2nd Symposium on Antimicrobial Resistance in Animals and the Environmnet(ARAE2007), December 17-19, 2007, Tours, France.

Technical Abstract: Introduction: Infection with Campylobacter is of global public health concern as one of the leading causes of enteric illness. Campylobacter is a fastidious organism and conventional culture from food or other samples can take several days, particularly if numbers are low and competing flora is high. Further, culture results in a recovery bias towards certain species. Once recovered, speciation is further problematic therefore several PCR-based systems have been developed for the speciation of Campylobacter isolates. Purpose: The purpose of this study was to compare the BAX® system assay (DuPont Qualicon), which is followed by gel electrophoresis for differentiating between C. jejuni and C. coli with a real-time PCR assay that runs on the BAX® Q7 instrument and differentiates between C. coli, C. lari, and C. jejuni. Methods: A total of 1,214 Campylobacter isolates were speciated using both gel based and real-time methods. Isolates originated from a variety of animal, human, and environmental sources. Cell lysates were prepared according to manufacturer’s directions and subjected to either the traditional PCR/gel based assay or to the real-time PCR/Q7 instrument. Results: The majority (n=1057, 87.1%) of the tested samples generated identical results by both methods. Of the 157 isolates (12.9%) that exhibited different results between the methods, two-thirds (n=100) were attributed to identification of mixed species (more than one species) by one of the methods. Additionally, the real-time assay identified seven C. lari isolates which cannot be done by the gel based system and time to result using the BAX® Q7 was less than half compared to the gel based assay. Significance: Use of the BAX® Q7 real-time assay accurately and reliably identified C. coli, C. lari, or C. jejuni in less time demonstrating its superiority compared to the BAX® gel based system.