FIG. 5.

Modified inoculation procedure for mouse colonization by wild-type (WT) and isogenic napA mutant H. pylori X47. Mice were inoculated with H. pylori two times, with the second inoculation 2 days after the first. Each time, the inoculum contained 2 × 10⁸ dead wild-type cells and 4 h later 2 × 10⁸ live test cells (i.e., either live wild-type cells or live napA mutant cells). Colonization was examined 3 weeks after the first inoculation. Data collection and analysis were done as described in the legend to Fig. 4. Panels A and B show results from two independent experiments. In both experiments, the napA mutant strain data are significantly lower (less colonization) than those of the wild type at a 99% confidence level, according to Wilcoxon rank test analysis.