FIG. 3.
Mouse colonization results of H. pylori X47 and its isogenic HP1553 mutant. The mice were inoculated with H. pylori two times (2 days apart), with a dose of 1.5 × 108 viable cells administered per animal each time. Colonization of H. pylori in mouse stomachs was examined 3 weeks after the first inoculation. Conditions that minimized oxygen exposure were used during stomach homogenization and homogenate dilution (see the text). Data are presented as a scatter plot (at log scale) of CFU per gram of stomach, as determined by plate counts. Each point represents the CFU count from one mouse stomach, and the solid line represents the geometric mean of the colonization number for each group (WT or HP1553 mutant). The baseline (log10 CFU/g = 2.7) is the detection limit of the assay, which represents a count below 500 CFU/g stomach.