FIGURE 5.

Lung histology 36 h following tracheal inoculation of PBS and inactivated S. haemolyticus at increasing load 10⁶, 10⁷, and 10⁸ CFU. LIS is represented as median values and interquartile 25th–75th range and extreme values (>2 SD). LIS is significantly different between groups: Kruskal–Wallis p = 0.0004; ^∗indicates p < 0.05 for 10⁸ CFU versus PBS and 10⁶ CFU. Thirty-six hours after tracheal inoculation of inactivated S. haemolyticus at 10⁶ and 10⁷ CFU, inflammatory cells infiltrate interalveolar septae, respecting alveolar space and lung architecture. The inoculation of 10⁸ CFU of inactivated S. haemolyticus induced invasion of inflammatory cells within alveolar space, hyaline membrane formation, and lung consolidation.