Biofilms in drinking water systems - a possible reservoir for Helicobacter pylori

Helicobacter pylori is a major bacterial pathogen involved in several gastrointestinal diseases. Transmission routes and reservoirs of H pylori are not well understood despite several studies. In contrast to many other infectious diseases, clinical symptoms allowing definitive diagnosis of infection are absent. Person-to-person transmission with faecal-oral and oral-oral routes have been proposed with socio-economic status and density of living as associated factors. Studies have shown that H pylori can survive in water for prolonged periods leading to a waterborne transmission route being proposed but not conclusively identified. This paper describes studies using mature heterotrophic mixed-species biofilms grown under oligotrophic conditions using a continuous-culture chemostat system. The biofilms were challenged with Helicobacter pylori (NCTC 11637). Results indicate the presence of H pylori associated with the biofilm for up to 192h post-challenge, suggesting that biofilms in water distribution systems could be a possible and as yet unrecognised reservoir of H pylori.