Fibrinolysis of Hemolytic Streptococci and Their Variability

Abstract

Our interest in the above correlation takes origin as follows: For the past 8 or 9 years one of us (Mellon) has studied with encouraging results a new serum approach to the therapeusis of hemolytic streptococcal infections. Treatment of the cases has been conducted exclusively in this hospital. Accompanying the serum's use we have frequently observed an in vivo dissociation of smooth (or smoothmucoid) cultures into more saprophytic colony types—sometimes characterized by rough-colonied hemolytic streptococci, sometimes by typical non-hemolytic diphtheroids, wholly avirulent.

Of special significance is the fact that such dissociation seems to be a direct sequence of a clinical crisis on the part of the severe cases, whose ultimate recovery is thereafter no longer in doubt. Obviously, a serum approach that would transform virulent organisms into their non-virulent phases, is rather different from the conventional bactericidal or antitoxic ones.

Only an occasional observer (Hadfield, et al. 1 ) in the field of fibrinolysis has directed attention to a correlation of virulence (as indicated by colony type) and fibrinolysis. Recently Tunnicliff 2 has shown correlation in a general way between R and S streptococci with respect to the increasing lysis and virulence as one proceeds from R to S. Reich 3 has shown that serial animal passage transformed a fibrinolytic strain of human origin into a non-fibrinolytic one suggesting a bovine origin; (Lancefield classification 4 ), and which on serial subculture returned to its original fibrinolytic state. Accordingly, we have wondered if this correlation might extend to certain variants such as the above; more particularly to diphtheroids whose in vivo dissociation from the streptococci had been confirmed by their occurrence in vitro, under controlled conditions.