Localization of prothrombin, fibrinogen, coagulase (Coa), and von Willebrand factor binding protein (vWbp) in staphylococcal abscesses.

BALB/c mice infected by intravenous inoculation with 1×107 CFU S. aureus Newman were killed 5 days post infection. Kidneys were removed and serial thin-sections stained by immunochemistry using rabbit antibodies (α) specific for mouse prothrombin (A, C), mouse fibrinogen/fibrin (B, D), S. aureus Coa (E, G) or S. aureus vWbp (F, H). Antibody deposition is revealed as brown pigment in tissues counterstained with hematoxylin. Displayed images are representative of three sampled kidneys. Panels C, D, G, and H illustrate antibody staining within a single abscess analyzed as four sequential sections, enlarged from an area in panels A, B, E, and F that is defined by a box with white margins. In panel C, the black box designates the area of the eosinophilic pseudocapsule surrounding the staphylococcal abscess community (SAC), which is marked by the black arrowhead. The SAC is surrounded by a zone of dead PMNs (white box), a zone of apparently healthy PMNs (red box), and a rim of necrotic PMNs (green box), separated through an eosinophilic layer from healthy kidney tissue.