Fig 3.

Pathologic and histological lesions of the rabbits intranasally inoculated with the 19 isolates. Rabbits were inoculated with 6.0 × 10⁴ CFU of the isolate. Fibrino pleuropneumonia (A) or fibrinopurulent pleuropneumonia (B) was observed in the rabbits that were euthanized during the 15-day experiment period. Pulmonary consolidation with hemorrhagic pneumonia (C) was observed in the rabbits that survived the experiment. No pathologic lesions were observed in the lungs of the intranasal control rabbits (D). Inflammatory exudates in the bronchiole and alveoli, penetration of red blood cells in the bronchiole and alveoli as well as degeneration of the alveolar epithelial cells (E) were observed in the lungs with fibrino pleuropneumonia or fibrinopurulent pleuropneumonia. Inflammatory exudates in bronchiole and alveoli and proliferation of alveolar epithelial cells (F) were observed in the lungs with pulmonary consolidation and hemorrhagic pneumonia. No histopathological lesions (G) were observed in the lungs of the intranasal control rabbits.