FIG. 3.
Histopathological (A to C) and immunohistochemical (D to F) analyses of liver. Histology sections were stained with hematoxylin II and eosin, while specific staining of E. chaffeensis-infected mononuclear cells was achieved using alkaline phosphatase-conjugated secondary antibodies with Fast Red TR/napthol AS-MX as the substrate (Sigma Chemical Co.). (A) Representative inflammatory response at day 8 postinfection. Several inflammatory cells and lesions are present (magnification, ×10; H&E staining). (B) Inflammatory response focus containing neutrophils and an apoptotic body (magnification, ×100; H&E staining). (C) Granulomatous inflammation on day 16 (magnification, ×40, H&E staining). (D) Control mouse liver; there is no immunostaining (magnification, ×100; hematoxylin staining). (E) E. chaffeensis-positive red staining in the cytoplasm of inflammation cells and mononuclear cells in hepatic sinusoids (magnification, ×100; hematoxylin staining). (F) E. chaffeensis-positive red staining in macrophage foci and mononuclear cells in hepatic sinusoids (magnification, ×100; hematoxylin staining).