Figure 3

Pathogenicity analyses. A Survival rates of mice infected with wild strain PmCQ2, ΔqseC and C-qseC, respectively, n = 10 mice/group. B–D Histopathology in lung of mice 24 h after infection with PmCQ2, ΔqseC and C-qseC, respectively. B Serious dilation and congestion in veins and alveolar wall capillaries, with inflammatory cell infiltration; C Slight dilation and congestion in alveolar wall capillaries, with a small number of red blood cells in some alveolar cavities; D Hyperemia and bleeding, with large number of red blood cells and cellulose exudation in the alveolar cavity. E–G Bacterial loads in the mice lungs at 8, 16, and 24 h after infection with PmCQ2, ΔqseC and C-qseC, respectively. Panels B–G: values are expressed as the mean ± SD, n = 6. * P < 0.05; *** P < 0.001; **** P < 0.0001.