OXYGEN-STABLE HEMOLYSINS OF GROUP A STREPTOCOCCI

Abstract
The relationship of the streptococcal hemolysin which is recognized on incubation of RBC with streptococcal cells (cell-bound hemolysin, CBH), to RNA hemolysin, a representative of oxygen-stable hemolysin (streptolysin S) has been studied. A number of similarities have been found in the conditions for optimal production of each of these hemolysins, a requirement for cysteine, Mg++, and glucose; maximal production by streptococci in the stationary phase; similar curves of pH-dependence. In both systems, the production of hemolysin was inhibited by certain antibiotics, by ultraviolet irradiation, and by sonic disruption and was absent in the same streptococcal mutant strain. The hemolytic activity of both systems was inhibited by lecithin, trypan blue, and papain. Similarities were also found in relative susceptibilities to the two hemolytic systems of erythrocytes of a number of animal species.