Chiang Mai Journal of Science

Helicobacter pylori is a causative agent of gastroduodenal and hepatobiliary diseases. Waterborne transmission of this bacterium has been suggested but has not been demonstrated in Thailand. The aims of this study were to determine the prevalence of H. pylori in environmental water and drinking water samples in northeastern Thailand by culture, nested PCR, real-time PCR, reverse transcription (RT)-nested PCR and RT-real-time PCR, and also indirect fluorescent antibody (IFA) assay. We also determined the prevalence of the virulence gene, cytotoxin-associated gene A (cagA).  The limits of detection of H. pylori in pure culture were 6 x 10² CFU/PCR and 1 CFU/PCR according to our newly developed RT-nested PCR and RT-SYBR green qPCR assays, respectively. The overall prevalence of H. pylori was 48% (39/81 samples). The bacterium was found in 76% of environmental water samples (16/21) and was especially common in waste water (80%). It was also found in 35% (23/60) of drinking water samples, according to the criteria adopted. Sixty-two percent (24/39) of H. pylori-positive samples were positive for cagA. Only 1% of samples  was positive for H. pylori by culture, 47% by nested PCR, 41% by real-time PCR, 43% by RT-nested PCR, 37% by RT-real-time PCR and 31% by IFA.  There was a high prevalence of virulent H. pylori in the water samples in this region, implying that drinking water and environmental water may be important sources for this pathogen, potentially leading to gastroduodenal or hepatobiliary diseases.