FIG 3.

Acid sensitivity of H. pylori strains. All strains were grown to an OD₆₀₀ of 0.3 and subjected to acid shock at pH 5.0 for 1 h (A), at pH 3.0 for 0.5 h (B), or at pH 3.0 for 1 h (C). The values are the percent cell survival after treatment, relative to the survival at pH 7.0. The data are means, with standard error bars, from three independent determinations, analyzed by Student's t test. **, P < 0.01; ***, P < 0.001; NS, no significant difference (P > 0.05); 26695 Dioc-treated and HP159 Dioc-treated denote cells grown with 50 μM dioctylamine before acid shock.