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

A laboratory model system was utilised to investigate the persistence of He licobacter pylori in mixed-species heterotrophic biofilms. A single-stage c ontinuous culture vessel was linked to a modified-Robbins device (mRD) inco rporating removable stainless steel coupons. The system was innoculated wit h H. pylori (NCTC 11637) and the fate of the organism monitored by polymera se chain reaction (PCR) analysis. Helicobacter pylori was detected in biofi lm material for a period of up to 192 h. Theoretical washout would have occ urred at around 48 h thus detection of H, pylori for a prolonged period aft er theoretical washout suggested that the organism possessed the ability to persist in the mixed-species heterotrophic biofilm. Preliminary studies us ing heat-inactivated H. pylori showed that the organism was not detected in biofilm material at any time post-challenge suggesting that the persistenc e of H. pylori in such material was a phenomenon requiring the organism to be in a viable state. Further investigations to assess the biological basis for the association of H. pylori with drinking water biofilms and the risk that this may pose to public health are being undertaken.