Cultivability and viability of enterohepatic and gastric Helicobacter spp. in water: implications for transmission

Abstract

The fact that Helicobacter pylori resides in the human stomach and has a low cultivability in water have been two of the main arguments for discarding rivers and drinking water distribution systems as possible vectors for the transmission of this gastric pathogen. On the other hand, most enteric bacterial pathogens, such as Campylobacter spp., are well-known for being able to use water as a vehicle of transmission and have accordingly longer cultivability times in water. Taking advantage of the fact that there are both gastric and enterohepatic Helicobacter spp., we have devised the following hypothesis: if only enterohepatic Helicobacter spp. are waterborne agents, then these bacteria should demonstrate longer cultivability and viability in water when compared to gastric Helicobacter spp. As such, we have exposed 13 strains from eight different species of Helicobacter to water and tracked their survival by standard plating methods and membrane integrity assessment. The species that survived for longer in water was H. pylori, whereas Helicobacter felis appeared to be the most sensitive. There is no correlation between the enterohepatic nature of Helicobacter spp. and an increased survival time in water, which implies that the role of water in transmission is likely to be similar for all species. This is the first work where the cultivabiliy and viability of non-pylori Helicobacter spp. in water has been assessed.