The occurrence of Campylobacter subtypes in environmental reservoirs and potential transmission routes

Aims: To identify potential reservoirs and transmission routes of human pathogenic Campylobacter spp. Methods and Results: An enrichment PCR method for the detection and identification of Campylobacter jejuni and/or Campylobacter coli in faecal, food and river water samples was applied to 1450 samples of 12 matrix types obtained from a defined geographical area. PCR-positive samples were cultured to yield isolates for typing, and the data for 616 C. jejuni isolates obtained. Serotyping and SmaI macrorestriction profiling using pulsed field gel electrophoresis revealed a high level of diversity within the isolates from each matrix. Campylobacter jejuni and C. coli subtypes indistinguishable from those obtained from human cases were detected in most of the matrices examined. No Campylobacter isolates were isolated from possum faeces. Conclusions: Ten of the 12 matrices examined may be involved in the transmission of human campylobacteriosis as they contained Campylobacter subtypes also isolated from clinical cases. Significance and Impact of the Study: Results indicate that, for this rural population, a range of potential transmission routes that could lead to campylobacteriosis exist. Their relative importance needs to be assessed from an exposure assessment standpoint.