title: Urease plays an important role in the chemotactic motility of Helicobacter pylori in a viscous environment.
abstract: Helicobacter pylori exhibits chemotactic responses to urea, flurofamide, acetohydroxamic acid, and sodium bicarbonate. In buffer, the chemotactic activities of a urease-positive strain were higher than those of the isogenic urease-negative strain. Moreover, the chemotactic activities of the urease-positive strain were increased in a viscous solution containing 3% polyvinylpyrrolidone, whereas those of the urease-negative mutant were not. These results are in accordance with the fact that the mutant strain did not show swarming in motility agar regardless of having flagella. Incubation of the wild-type strain with flurofamide resulted in partial inhibition of the chemotactic activities in the viscous solution. In addition, incubation with acetohydroxamic acid, a low-molecular-weight, diffusible urease inhibitor, resulted in complete loss of chemotactic activity in the viscous solution. The inhibition of the chemotactic activity by urease inhibitors paralleled the inhibition of urease. The chemotactic activity of H. pylori was also inhibited by the proton carrier carbonyl cyanide m-chlorophenylhydrazone, showing that H. pylori utilizes proton motive force for motility. These results indicate that cytoplasmic urease plays an important role in the chemotactic motility of H. pylori under a condition that mimics the ecological niche of the bacterium, the gastric mucous layer.
authors.affiliation: Department of Microbiology, Yamaguchi University School of Medicine, Ube, Yamaguchi 755-8505, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Yoshiyama
authors.forename: H
authors.initials: H
authors.lastname: Takeuchi
authors.forename: T
authors.initials: T
authors.lastname: Mizote
authors.forename: K
authors.initials: K
authors.lastname: Okita
authors.forename: T
authors.initials: T
authors.lastname: Nakazawa
mesh_terms: D001549:Benzamides / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016480:Helicobacter pylori / Q000187:drug effects / Q000502:physiology*; D011205:Povidone / Q000494:pharmacology; D018892:Proton-Motive Force; D014475:Uncoupling Agents / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology; D014510:Urease / Q000037:antagonists & inhibitors / Q000502:physiology*; D014783:Viscosity
chemical_list: D001549:Benzamides; D004791:Enzyme Inhibitors; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C032764:flurofamide; D014508:Urea; D014510:Urease; D011205:Povidone