CLOT FORMATION BY GROUP-A STREPTOCOCCI

Group A streptococci of several different M serotypes can cause human plasma to clot in nutrient-poor media. Addition of glucose to the medi um prevents dot formation. Once formed, clots are stable for several d ays and can be lysed on addition of exogenous streptokinase or urokina se, Clot lysis can also be achieved by addition of glucose to a clot c ontaining wild-type group A streptococci but not clots containing an i sogenic mutant in which the ska gene was inactivated.