FIG 1.

H. pylori responds to arginine, fumarate, and cysteine as TlpA-dependent chemoattractants in the temporal chemotaxis assay. Cultures of H. pylori PMSS1 WT and ΔtlpA strains were grown overnight, back-diluted, and then incubated until an OD₆₀₀ of 0.12 to 0.15 was reached. Cultures were treated with water (Mock) or various concentrations of compounds, as indicated. For panels C and E, the pH of cysteine, thiamine, malic acid, and α-ketoglutarate stocks was adjusted using NaOH to match the pH of the water used for the untreated control. The cells were immediately filmed, and direction changes were counted over a 3-s swimming period in at least 100 cells per treatment from 3 biological replicates. Data are normalized to the values for the untreated control for each strain, as described in Materials and Methods. Error bars represent the standard errors of the means. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (comparisons to the untreated control per strain using two-way ANOVA with Dunnett’s multiple-comparison test).