An intracellular hemolysin of group A streptococci. I. Influence of sonic energy and pH on hemolytic potency

In a previous paper, Schwab (1955) described a bemolysin of group A streptococci which is con-fined to the bacterial cell and released upon breakdown of the cell structure by sonic oscilla-tion. The studies reported here were undertaken to determine if the hemolytic activity of the cellular extracts could be ascribed to streptolysin 0 or 5, or whether it is a distinct hemolytic product of the streptococcus. The results indicate that the intracellular hemolysin can be readily distinguished from streptolysin 0 and has certain properties which differentiate it from streptolysin S. Thus, at least several strains of group A streptococci possess an endotoxin unrelated to the exotoxins which hav