Streptokinase is produced from

S.equisimilis produces streptolysin O, streptokinase (antigenically distinct from that produced by S.pyogenes) and other extracellular substances. S.equisimilis is the source of streptokinase used for thrombolytic therapy in patients. Group C streptococci are predominantly animal pathogens. Group C strains isolated from human sources usually belong to the S.equisimilis species. It can cause upper respiratory infections, as well as deep infections such as endocarditis, osteomyelitis, brain abscess, pneumonia and puerperal sepsis. Strains are tolerant to penicillin and serious infections may not respond to penicillin treatment. The addition of gentamycin is recommended in serious cases. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 219