Prolonged survival and cytoplasmic pH homeostasis of Helicobacter pylori at pH 1.

Prolonged Survival and Cytoplasmic pH Homeostasis of Helicobacter pylori at pH

Energetics of Helicobacter pylori and its implications for the mechanism of urease-dependent acid tolerance at pH 1.

In the presence of urea the neutrophilic human pathogen Helicobacter pylori survives for several hours at pH 1 with concomitant cytoplasmic pH homeostasis. To study this effect in detail, the transmembrane proton motive force and cytoplasmic urease activity of H. pylori were determined at various pH values. In the absence of urea, the organism maintained a close-to-neutral cytoplasm and an inte...

Effect of physical environment on survival of Helicobacter pylori.

AIMS To determine the effects of physical conditions on survival of Helicobacter pylori in aquatic environments. Survival for prolonged time intervals would implicate environmental water as a possible source of infection. METHODS The effect of ionic strength, pH, urea, protein and composition of incubation atmosphere on the survival of H pylori NCTC 11637 and two clinical isolates (CI 82 and ...

Role of the Helicobacter pylori sensor kinase ArsS in protein trafficking and acid acclimation.

Helicobacter pylori survives and grows at low pHs via acid acclimation mechanisms that enable periplasmic pH homeostasis. Important components include a cytoplasmic urease; a pH-gated urea channel, UreI; and periplasmic α-carbonic anhydrase. To allow the rapid adjustment of periplasmic pH, acid acclimation components are recruited to the inner membrane in acid. The ArsRS two-component system, i...

Expression of the Helicobacter pylori ureI gene is required for acidic pH activation of cytoplasmic urease.

ureI encodes an integral cytoplasmic membrane protein. It is present in the urease gene cluster of Helicobacter pylori and is essential for infection and acid survival, but its role is unknown. To determine the function of UreI protein, we produced H. pylori ureI deletion mutants and measured the pH dependence of urease activity of intact and lysed bacteria and the effect of urea on the membran...