Comparative Study of Fibrinolytic and Anticoagulating Properties of Streptococcus hemolyticus and Streptococcus fecalis (Enterococcus)

Abstract

Tillett and Garner 1 made the interesting observation that hemolytic streptococci may produce a powerful fibrinolysin. Their findings were corroborated and extended by several authors, including Dart, Dennis and Berberian, Van Deventer, Hare and Colebrook, Hatfield,. Magee and Perry, Lippard, Johnson and Wheeler, Madison, Meyers, Keefer and Holmes, Reich, Schmidt, Stuart-Harris, Tunnicliff and others. The fibrinolysin produced by hemolytic streptococci in vitro has the following main properties: It dissolves human but not animal plasma-clots, with the exception of rhesus plasma, as demonstrated by Van Deventer and Reich 2 ; it is produced in infusion-broth in rather high concentration, and it may be neutralized by strepto-coccal antiserum as well as by serums of patients recovering from streptococcal infections. Besides the fibrinolysin, glucose-broth cultures of hemolytic streptococci may contain a second factor which inhibits coagulation of both human and animal plasma, as observed by Dennis and Berberian, 3 Dart, 4 Witebsky and Neter. 5 Dennis and Berberian demonstrated such an anticoagulant also in a glucose-broth culture of one strain of S. viridans. These authors reported that type-specific (El) antiserum neutralized the El anticoagulant when used in amount of 0.2 cc. or more. They concluded that there is evidence that fibrinolysin and anticoagulant are antigenic and exhibit some degree of type-specificity. The following facts, however, seem to cast doubt on the conception of the antigenic or even type-specific nature of bacterial anticoagulants: (1) Normal serum and heterologous antisera inhibit the streptococcal anticoagulant to about the same degree as does streptococcal antiserum. (2) Normal spinal fluid, known to be rather poor in normal antibody-functions, counteracts anticoagulant as well as normal serum. We, therefore, believe that this type of neutralization of the anticoagulant is due to non-specific factors operative in serum and spinal fluid respectively.