Potential transmission sources of Helicobacter pylori infection: detection of H. pylori in various environmental samples.

Purpose: Helicobacter pylori is one of the most common human infectious agents which may be transmitted via water. This study was designed to test H. pylori presence via molecular methods in various aquatic environments as well as sewage sludge (SS) to understand the role of these environments in the pathogen's transmission.
Methods: specific primers for the 16S rRNA and ure A genes of H. pylori were used in a nested and semi-nested PCR, respectively. Detection sensitivity of H. pylori in environmental samples by semi-nested PCR was also compared with real-time PCR. Analysis of fecal coliforms (FC) as pollution indicator bacteria was also performed.
Results: H. pylori 16S rRNA gene was detected in 36% (14/39) of wastewater samples and 8% (2/25) of water samples, while amplification of ure A gene yielded only two positive result s . None of the SS samples were positive for H. pylori and real-time PCR could not identify H. pylori in any of the samples. The results showed no correlation between the presence of H. pylori and FC.
Conclusions: Our result revealed the widespread presence of H. pylori in wastewater samples which indicates wastewater may be a source for dissemination and transmission of H. pylori infection. Further research is needed to determine the risk of H. pylori in wastewater reuse for irrigation of crops.
Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest.