Efficacy of filter types for detecting Campylobacter jejuni and Campylobacter coli in environmental water samples by polymerase chain reaction

A PCR assay for the detection of Campylobacter jejuni and Campylobacter coli in water

A PCR assay has been developed for the detection of Campylobacter jejuni and Camp. coli in water samples. The sample is filtered through a membrane which is subjected to sonication to release the impacted cells. After removal of the filter from the cell suspension and a freeze/thaw cell lysis step, a semi-nested PCR is carried out on the filtrate using the primers CF02, CF03 and CF04 (Camp. jejuni flaA and flaB gene sequences). Incorporation of a sonication stage allows removal of the filter membrane since they have been shown to inhibit the PCR. In experiments with spike water samples (20 ml) a theoretical sensitivity of 10-20 campylobacter cells ml-1 was achieved. Using a sample volume of 100 ml this sensitivity can be increased to approximately 2 campylobacter cells ml-1.

Nucleic acid probes for the food industry

Recombinant DNA technology has revolutionised microbiological analysis by providing rapid and sensitive methods for the direct detection and identification of organisms. These advances have been most successfully applied to basic research and to clinical microbiology. Continued improvements in the techniques and in assay formats have now brought them to the stage where they could be useful on an industrial scale. The use of nucleic acid techniques for the identification of bacteria of importance to the food industry is discussed with emphasis on developments in practical applications.