Figure 7.

Bacterial colonization and survival of infected mice

(a) Nasopharyngeal colonization of mice (n = 6 per group) infected with the indicated strains at 2 × 10⁷ CFU intranasally and collected from the nasopharyngeal lavage fluid 48 h post-infection. CFU of infected bacteria present in (b) lung homogenates, (c) blood, and (d) spleen homogenates. (e) Survival of mice (n = 12 for each group) after intranasal infection with 1 × 10⁷ CFU. Survival was analyzed using log-rank comparisons. ***P < 0.001 (f) Photomicrographs of H&E-stained lung tissues of mice 48 h after challenge with the indicated strains with the same challenge dose as the colonization experiments.