[A study on acid resistance of Helicobacter pylori]

Abstract

Physiological saline solutions, each adjusted to pH 1.0, pH 2.0 and pH 7.2, and added urea and urease inhibitor (Acetohydroxamic acid), were inoculated with a culture solution of Helicobacter pylori NCTC11637 strain derived from man, and allowed to react for 10, 30, 60 and 120 minutes. After five days of incubation on a blood agar medium, remaining viable H. pylori was counted. Survival of H. pylori was inadequate under the conditions of pH 1.0 and pH 2.0, but survival up to 120 min was observed on addition of urea. Further, on addition of urease inhibitor the survival time was reduced. H. pylori survived under the condition of pH 7.2 independent of addition of urea and urease inhibitor. Urea is essential for survival of H. pylori under strongly acidic conditions, and utility of urease inhibitor was observed for inhibition of survival of H. pylori.