Isolation and properties of a streptococcal hemolysin formed in the presence of colistin.

The strains of beta-hemolytic streptococci capable of producing streptolysin S, Su and Blackmore, were found to be useful in acquiring CIH (colistin-induced hemolysin), while C203U strain, which produces only streptolysin O, was ineffective in this respect. In these experimental series, much amounts of coccal cells from exponential phase of culture were necessary for obtaining good results and for its reproducibility. Further experiments showed that an oligoribonucleotide, rich in guanylic residu, separated by DEAE-cellulose column chromatography could be favourably compared with RNase-core in production of CIH in the medium. Yield of this hemolysin was fully dependent upon the concentration of K+ (100 mM), Mg2+ (10 mM) ions and maltose (5 mM) contained in the reaction medium, respectively. When one of three components was omitted, CIH was not obtained, even though colistin and oligoribonucleotide were present. Additionally, crude preparation of CIH was fractionated on DEAE-cellulose column, resulting in isolation of two peaks (F-I and F-II) with hemolytic activity. Considering the response of two hemolytic fractions to various inhibitors and activators, F-II is likely to correspond to streptolysin S, while F-I may, at least, be a segment differed from the streptolysin, S and O.