FIG. 3.

Exposure of WT and the rocF::aphA3 mutant of H. pylori 26695 to acid. H. pylori strains were treated with 0.1 M citrate-phosphate buffer at the pHs indicated in the presence or absence of 5 mM urea. After 30 min, bacteria were washed, diluted, and plated for viable CFU. A representative experiment of six experiments, each conducted in duplicate, is shown. Data are presented as the log₁₀ CFU killed, which is the log₁₀ CFU that survived at time = 0 min (T₀, 10⁸ to 10⁹) minus the log₁₀ CFU that survived at 30 min under the condition indicated.