Helicobacter pylori: longer survival in deep ground water and sea water than in a nutrient-rich environment.

Helicobacter pylori can infect the human stomach through the ingestion of water. Only a few studies on the morphological changes and viability of this bacteria in DGW (deep ground water) have been reported and none in natural seawater (SW). Morphological changes and the culturability of H. pylori after storage in DGW or SW for a week were examined to see if they could be a factor associated with the high infection rate in Japan. An H. pylori strain, ATCC 43504, stored in DGW and in SW at 4 degrees C for 7 days, was examined daily for any ultrastructural changes and culturability. The same H. pylori strain was also cultured in conventional Brucella broth culture liquid medium as control and was similarly observed. Bacteria kept in DGW and SW were found not only to retain their spiral form but also to show better culturability than those kept in the control nutrient-rich medium (p<0.01). Thus, natural waters were found to be more conducive to H. pylori survival than a nutrient-rich medium.