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[The heterogeneity of Streptococcus pyogenes strains isolated from clinically healthy and sick children in an organized collective].

Experiments on typed strains used as an example revealed that kinetic curves obtained in the lysis by endo-N-aretylmuramidase of virulent strains greatly differed from those obtained from nonvirulent ones: the lysis rate of M+ variants was less than that of M- variants; M- strains gave rather steep kinetic curves of lysis, while those of M+ strains were more declivous. In this study group A S. pyogenes cultures isolated from healthy and sick children in a summer camp were used. The study revealed that cultures, newly isolated from healthy and sick children, were heterogeneous with respect to the M+ and M- state of group A S. pyogenes strains, the amino acid composition of pepsin fragments of M-proteins in the cultures of streptococcus M 1 under study being also heterogeneous.

Amino Acids↗
PubMed1959

Studies on Streptococcus pyogenes. IV. Effect of whole cells, M and C antigens, and other components of the cell on adrenalectomized rats.

Heat-killed cells of Group A streptococci caused death of the adrenalectomized rat. While the adrenalectomized rat readily succumbed to intraperitoneal infection with living cells, death was due primarily to toxicity. The normal rat was highly resistant under either condition. For studies on the toxic materials, the cells of numerous serological types of group A streptococci, and of a Group B and a Group D streptococcus, were extracted with 0.1 N HCl at 100 degrees C. or by sonic oscillation. The extracts, containing macromolecular components, were subjected to chemical fractionation and purification. C substance and M protein of Group A streptococci released from the cell by sonic oscillation were toxic to the adrenalectomized rat in quantities of 1 mg./100 gm. rat. Death usually occurred within 2 hours. On the other hand, C substance and M protein released from the cell with HCl at 100 degrees C. were relatively non-toxic to the adrenalectomized rat. The sonic-extracted C substance of streptococcal Groups B, C, and D was also toxic. The toxic property of the C and M preparations was neutralized in vitro in each case by group and type-specific rabbit antiserum. Heterologous antiserum was without effect. Adrenalectomized rats which received homologous antiserum 18 hours before challenge were also resistant to the toxicity of the C and M preparations. Trypsin destroyed the toxic effect of the M protein preparations and was without effect on the toxicity of the C substance. The R antigen and a nucleoprotein component of Group A streptococci, preparations of protein from Groups B and D streptococci, and coagulase from Staphylococcus aureus were all found to be essentially non-toxicic for the adrenalectomized rat. Large quantities of peptone, crystalline albumin, and rabbit serum were also without effect.

Adrenalectomy↗