Figure 4

Representative histopathological images (A–F) and immunohistochemistry (IHC) stainings (G–H) of caprine respiratory tissues. Tissues are derived from goats experimentally infected with Mycoplasma capricolum subsp. capripneumoniae (C–F) and from a mock-infected control group (A, B no histopathological lesions present). C, D Lesions of the acute form of contagious caprine pleuropneumonia; airways filled with neutrophilic granulocytes (asterisk), edema, hemorrhage and fibrinoid degeneration and necrosis of vascular wall (arrow). E, F Lesions of the chronic form of CCPP; abscess formation with central coagulative necrosis and fibrous encapsulation (arrow) and the beginning of bronchiolitis obliterans in a bronchiole (clover). G Mycoplasma capricolum subsp. capripneumoniae-positive IHC staining on apical cell border of ciliated respiratory epithelial cells in the trachea. H Mycoplasma capricolum subsp. capripneumoniae-positive IHC staining in alveoli associated with neutrophilic granulocytes infiltration. Size standards are displayed in the lower right corner of each picture: A = 1 mm; B = 200 µm, C = 200 µm, D = 50 µm, E = 1 mm; F = 100 µm; G + H = 20 µm.