Thermophilic campylobacters in surface water: a potential risk of campylobacteriosis

Campylobacteriosis caused by Campylobacter jejuni, Campylobacter coli and Campylobacter lari is one of the most frequently occurring acute gastroenteritis diseases in humans. An important risk factor is untreated drinking water. Thermotolerant campylobacters were isolated from Bo River water using 100-ml filtrate samples. Campylobacters were isolated from 32 of 60 samples (53.3%). Of the 75 strains isolated, 47 (62.7%) were detected using the enrichment procedure and 28 (37.2%) by direct plating of the filter. Campylobacter coli was the dominating species (44%) followed by Campylobacter jejuni (34.6%) and Campylobacter lari (14.7%). Five isolates (6.7%) could not be classified. Campylobacter were isolated without the occurrence of fecal coliforms indicating that fecal coliforms cannot be used as index bacteria to predict the occurrence of campylobacters. Case-control studies have indicated untreated drinking water and barbecuing as important risk factors, and waterborne campylobacteriosis has been caused by the three species isolated. The virulence factors of isolated environmental strains are not fully known. It was concluded that it is hazardous to use untreated surface water for drinking. Special efforts should be taken to avoid contamination of agricultural products from irrigation.