Fig. 3
Histological lesions in the lungs of the rabbits intranasally infected with 6.0 × 104 CFU of the s4 (hematoxylin-eosin staining, × 400). A Inflammatory exudates appeared in the bronchiole and alveoli as well as degeneration of the alveolar epithelial cells in the one rabbit with hemorrhagic pneumonia; B Inflammatory exudates in the bronchiole and alveoli as well as proliferation of alveolar epithelial cells in the two rabbits with pulmonary consolidation and weak hemorrhagic pneumonia; C Proliferation of alveolar epithelial cells in the five rabbits with weak hemorrhagic pneumonia; D The lung tissues from the rabbits of negative control group