The presence of diphosphopyridine nucleotidase (DPNase) in filtrates of cultures of hemolytic streptococci was first described in 1956.1,2 Among several bacterial species studied, only streptococci of Groups A, C, and G produced this extracellular enzyme. The capacity to release DPNase during growth of different types of Group A strains varied markedly; many strains produced no enzyme, while others elaborated large amounts. In general, DPNase production appeared to be restricted to those serological types of Group A streptococci now known to be associated with acute glomerulonephritis.3,4
DPNase destroys the coenzyme, diphosphopyridine nucleotide (DPN), thus interfering with the oxidative metabolism of mitochondria in vitor.1 In addition, Wilson4 has observed a close association between the capacity of Group A streptococci to kill leukocytes in vitro after phagocytosis and the capacity of the strain to produce DPNase. Ayoub and Wannamaker5 have observed higher titers of neutralizing antibodies against DPNase