Interaction of Group A Streptococci with Human Plasmin(ogen) under Physiological Conditions

A series of methods for analyzing the interaction of group A streptococci with the human plasminogen system are described. Examples of group A streptococcal isolates capable of assembling surface plasminogen activator activity when grown in human plasma are presented and the key requirements for this process are evaluated. The stabilities of cell-associated plasmin and plasminogen activator complexes are compared and a model for the interaction of group A streptococci with the plasminogen system in an infected host is presented.