From a wild type strain Challis of the group H streptococcus, greening (Challis α) and β‐hemolytic (Challis β) colonies were isolated on horse blood agar. Both colonies formed greening on sheep blood agar, and no significant differences were found in their biological, serological and chemical analyses. They, however, showed clear differences on the transformability. Transformability, the producibility of competence‐provoking factor (CPF) and competency which have been reported on the Challis strain were all found in Challis β strain. On the other hand, Challis α strain did not produce antibiotic‐resistant transformants with the addition of CPF, and could not produce CPF even when the cells were cultured under various conditions of incubation or treated with lysozyme or detergents. The transformabilities of antibiotic‐resistant mutants obtained from the Challis β strain were lower than those of the original Challis β strain, as pointed out by other investigators, while the Challis α strain became transformable on antibiotic resistance only when it acquired streptomycin resistance. In the Challis β strain and the antibiotic‐resistant mutants of Challis α strain, the separate markers of streptomycin, penicillin, tetracycline, mitomycin C, as well as the combinations of these markers were found to be transformed at the highest rate in the strains having transformation of streptomycin resistance. The findings are discussed with respect to incorporation of deoxyribonucleic acid into recipient cells and to the reports of other workers.
Two types of hemolysis, α and β were formed by group H streptococcus wild type strain Challis on horse blood agar, and both of the hemolytic markers could be transformed in each. α‐Hemolysis‐acquired transformants lost the competence‐provoking factor producibility (CPF–). When DNAs, obtained from strains Challis α, dihydrostreptomycin sulfate‐resistant Challis α, and Wicky, were used CPF– transformants appeared in high frequencies. DNAs from incompetent β cells grown in ET3 medium for 6 hr or in heated ET3 medium for 2 hr also transferred the CPF–. CPF producibility (CPF+) was transformed with DNA from competent Challis β, while it was not transformed to Challis β with DNA from Wicky cells in competent and incompetent phases. Among β transformants obtained there were (1) those having CPF+ and competency, (2) those having competency but CPF–, and also (3) those defective in both. Based upon these results, the transformability is discussed regarding close relation to DNA receptor site or CPF attachment and also on the probable transfer of itself by transforming DNA.
Transfers of Streptococcus pyogenes strain T12 in Todd–Hewitt broth containing stepwise increases in amounts of mitomycin C (MC) gave rise to slight changes of their colonial appearances. Variants thus obtained were examined for antibiotic and bile resistances; production of streptolysin‐S, ‐O and deoxyribonuclease; growth in alkaline medium, high salt concentration, and at 10 C and 45 C; sugar fermentations, and precipitin reactions. Four strains retained group A antigen, but some of them lost the ability to produce hemolysins and deoxyribonuclease, and acquired resistance to bile, penicillin and streptomycin as well as MC, and to physical environments. Four other strains lost group A antigen and acquired new antigens common to cells of group C, group D, or highly antibiotic‐resistant mutants reported previously. A variant which reacted with group C antiserum contained galactosamine, but not glucosamine, while the parent strain showed the reverse pattern. Many other variants contained both hexosamines. Even a variant, strain TL3‐2, reacted strongly only with group A antiserum, but contained glucose and both hexosamines. These strains having galactosamine possessed uridine diphosphate (UDP)‐N‐acetylglucosamine‐4‐epimerase activity which converted the substrate into UDP‐N‐acetylgalactosamine, while the parent strain failed to demonstrate the existence of this enzyme. The variants were discussed with respect to the group A streptococcal variations possessing no more original characteristics.
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