Effect of Staphylococcus aureus Coagulase on the Hemophilia Type A Plasma

Background and aim: Clotting occurs when fibrinogen is converted into fibrin by thrombin. under physiological conditions, the proteolytic activation of the inactive precursor prothrombin into thrombin is the final step in the tightly regulated coagulation cascade. Staphylocoagulase secreted by Staphylococcus aureus directly binds to prothrombin to form the staphylothrombin complex and thus by passes the coagulation cascade and its physiological regulation. The aim of this study is effect of staphylococcus aureus coagulase on the hemophilia type A plasma Materials and Methods: The coagulase test examined on 15 hemophilia type A plasma, 15 human normal plasma and 15 rabbit plasma. Factor VIII in the blood samples of hemophilia were determined, then S. aureus ATCC 8325/4 col were incubated in all of the samples. There were two conroll , possetive and negative .For negative control S. epidermidis was inoculated in citrated plasma of hemophilia sample and for positive control Staphylococcus aureus ATCC 8325/4 col was inoculated in citrated rabbit plasma. Coagulse test Plasma coagulation was checked after 1, 2, 4, 8, 20 and 24 h of aerobic incubation at 37°C.. Results: coagulase clotted all 15 cases of hemophilia plasma with different levels of factor VIII whitin less than 24h . there is no relationship between time of Coagulation and rate of factor VIII. Conclusion: It seems that the coagulase have a successful role for clotting of blood in patients with Factor VIII deficiency (hemophilia) in which blood clots don't form properly. coagulase enzyme don't use factor VIII in the path of blood coagulation so clotting blood in hemophilia Patient with coagulase can be a vision to help these patients in this process.