Helicobacter pylori Requires TlpD-Driven Chemotaxis To Proliferate in the Antrum

Abstract

ABSTRACTDifferent disease outcomes ofHelicobacter pyloriinfection correlate with distinct inflammation patterns. These different inflammatory distributions may be initiated by differences in bacterial localization. OneH. pyloriproperty known to affect murine stomach localization is chemotaxis, the ability to move in response to chemical cues. In this report, we used nonchemotactic mutants (Che−) to analyze whether chemotaxis is required for initial colonization of particular stomach regions or for subsequent growth therein. We found thatH. pyloribehaves differently in the corpus, antrum, and corpus-antrum transition zone subregions of the stomach. This outcome suggests that these regions contain unique chemotactic signals. In the corpus,H. pyloriutilizes chemotaxis for initial localization but not for subsequent growth. In contrast, in the antrum and the corpus-antrum transition zone, chemotaxis does not help initial colonization but does promote subsequent proliferation. To determine which chemoreceptor is responsible for the corpus-antrum phenotypes, we infected mice with strains lacking each chemoreceptor. Strains lacking TlpA, TlpB, or TlpC displayed only modest deviations from the wild-type phenotype, while strains lacking TlpD resembled the Che−mutant in their antral colonization defect and fared even worse than the Che−mutant in the corpus. Additional analysis showed that inflammation is worse in the antrum than in the corpus in both wild-type and Che−mutant infections. These results suggest that chemotaxis, specifically, that controlled by TlpD, is necessary forH. pylorito survive or grow in the environment of increased inflammation in the antrum.