Antibodies against Coa and vWbp block the clotting of blood by staphylococcal coagulases.

(A) His6-Coa and His6-vWbp were purified by affinity chromatography from E. coli and analyzed on Coomassie-stained SDS-PAGE. (B) Rabbit antibodies were raised against His6-Coa or His6-vWbp, affinity purified and analyzed by ELISA for immune reactivity with purified coagulases. Data are averaged from three independent experimental determinations. (C) Lepirudin-treated mouse blood was treated with PBS (mock), irrelevant antibodies (αV10) or antibodies directed against Coa (αCoa), vWbp (αvWbp) or both coagulases (αCoa/αvWbp) prior to infection with S. aureus Newman and incubation for 48 hours at 25°C. (D) Lepirudin-treated mouse blood was treated with antibodies as above. Blood samples were then incubated with functionally active Coa or vWbp and coagulation time recorded.