STUDIES ON THE EFFECT OF NUCLEIC ACID UPON THE SYNTHESIS OF OXYGEN STABLE STREPTOLYSIN BY CERTAIN STRAINS OF STREPTOCOCCUS PYOGENES

Abstract

The hemolysin produced by Streptococcus pyogenes has long been the subject of many researchers. (For early literature see M'Leod, 19121), Hellens, 19132), and Kruif and Ireland, 19203).) Recent work by Todd, and by Weld are particularly noteworthy: Weld (19344), 19355)) found that a powerful hemotoxin might be extracted from living hemolytic streptococci by agitating the organisms in normal serum and subsequently filtering the serum. In a satisfactory experiment the filtrate has a very high hemolytic titre and is lethal to mice in small doses intravenously. On the other hand, it has been demonstrated by Todd (19346), 19387), 19398)) that group A hemolytic streptococci produce two distinct varieties of streptolysin:(a) Streptolysin O which is oxygen sensitive and antigenic.(b) Streptolysin S which is serum-extractable and apparently non-antigenic.Although much work has been done in the research concerning streptolysin, all these experiments were carried out with the filtrate hemolysin or the supernatant fluid of the culture; thus making more difficult the most essential points in the study of streptolysin, that is its isolation and purification.In 1939, the phenomenon of “the high promotion by nucleic acid of the production of hemolytic toxin of Streptococcus pyogenes, streptolysin, ” was discovered by Okamoto.9) For the first time, it then became possible to carry out studies on streptolysin uncomplicated by the presence of serum.Within a short time, the study on this phenomenon lifted our knowledge of the streptolysin (S') (the term “streptolysin S'”was designed by Bernheimer to indicate its similarity in properties to Todd's streptolysin S. See below.) from the status of “bacterial toxin of chemically unknown nature” to a point, where the essential quality of this toxin could be almost fully understood.Thus, we are able to establish the isolation method10)11)15)19) of the streptolysin in relatively pure form from the culture of hemolytic streptococci grown in 1% Nucleic-Acid-Broth.It was found that the streptolysin (S') is not protein in nature, and it therefore probably follows that this toxin possesses no antigenic property. Further chemical investigations of the purified streptolysin-fraction (minimum hemolytic concentration=1: 200, 000, 000), finally led to the discovery that this hemotoxin is a nucleic acid derivative of polynucleotidic form.12)13)16)17)On the other hand, it was found that the dyestuff of trypan blue series possesses a distinct specific antidotal activity against this streptolysin.The excised intestine (or uterus) suspended in Ringer's solution is aroused to contracture by streptolysin.18)Our observations have been quickly confirmed and extented by Alan W. Bernheimer of the Department of Microbiology, College of Medicine, New York University**.20)24)Bernheimer reported in his paper20) as follows: “Streptolysin S”.-The sodium salt of yeast nucleic acid has been shown by Okamoto to induce the formation of a potent hemolysin in infusion broth cultures of hemolytic streptococci. The observations of Okamoto have been confirmed in this laboratory using the C203S strain of Streptococcus pyogenes. The hemolysin obtained by Okamoto's procedure was found to differ from streptolysin O in several respects among which were failure to be activated by cysteine and failure to be inhibited by cholesterol or by antistreptolysin O. Its properties, so far, as they have been studied agree in all respects with those of streptolysin S21) but since complete proof of its identity with streptolysin S is lacking, it may provisionally be designated streptolysin S'.