Methods for the detection of Campylobacter in sewage: evaluation of efficacy of enrichment and isolation media, applicability of Polymerase Chain Reaction and Latex Agglutination Assay

In this investigation several combinations of enrichment and isolation media in the conventional Most Probable Number procedure for the isolation of Campylobacter from sewage are compared. Furthermore, the potentials of the Polymerase Chain Reaction (PCR) assay and the Latex Agglutination Assay (LAA) are assessed for rapid detection and identification of Campylobacter in the culturing procedure for sewage samples. No significant difference in efficacy was observed for the various enrichment broths (Preston Broth (PB) and Charcoal Cefoperazone Deoxycholate Broth (CCBD)) and isolation media tested (Columbia Agar Base (CAB +), Campylobacter Blood-Free Selective Medium-Modified CCDA-Preston (CCDA), Campylobacter Blood-Free Selective Medium-modified CCDA improved (CCDA +) and Campylobacter Agar Base Karmali (KAR)). However, the selectivity of the isolation media was not optimal. The LAA had a positive predictive value of 39% and therefore, this assay should not be used as a rapid detection method. The PCR culture assay is suitable for the detection of Campylobacter in sewage enrichments; the method is faster and has a higher detection ability than the conventional culturing procedure, also when including 4 isolation media. For a qualitative analysis by conventional culturing 1 ml of the 10 −1 dilution of sewage is preferably enriched, and for the PCR assay raw sewage can be enriched for qualitatively detecting Campylobacter.