Spectrum of pathogen- and model-specific histopathologies in mouse models of acute pneumonia
Pathogens were visualized using special stains commonly used for bacterial detection, including the Gram stain for Gram-positive pneumococci (A, dark blue, arrowhead), and Giemsa stain of Klebsiella (B, light blue, arrowhead). Immunohistochemical staining methods were employed to localize specific antigens of S. pneumoniae (C, red, arrowhead) and IAV (D, red, arrowhead). Triamino-tritolyl-methanechloride (Neufuchsin) was used as chromogen (red) and hematoxylin (blue) as counterstain. Bars (a–d), 20 μm.