Enumeration of Campylobacter in New Zealand recreational and drinking waters

Aims: To use a published polymerase chain reaction (PCR) method for the det ection and identification of thermotolerant Campylobacter species (Camp. je juni, Camp. coli and Camp. lari) in tandem with a Most Probable Number (MPN ) technique to enumerate these species in water samples. Methods and Results: An initial study of 42 river water samples compared th e use of conventional culture and PCR methods for the detection of Campylob acter in MPN enrichment tubes. It was found that all samples positive by cu lture were also positive bit PCR. Thirty-seven percent more MPN tubes were positive by PCR compared with culture. The MPN/PCR technique nias subsequen tly applied to 96 additional samples collected fi om rivers, drinking, roof and shallow ground water. Campylobacter was especially prevalent in river water (60% positive) and shallow ground n ater (75% positive) samples. Drin king water (29.2% positive) and roof water (37.5% positive) also contained Campylobacter, but the numbers detected were very low (maximum 0.3 and 0.56 MPN 100 ml(-1), respectively). Conclusions: River waters contained Campylobacter at higher levels than any other water type and in a high percentage of the samples. Although Campylo bacter was present in treated drinking water, the levels detected were low. Significance and Impact of the Study: These results suggest that water may act as a significant transmission route for human campylobacteriosis.