Previous studies on the antigenic composition of group A hemolytic streptococci have shown that the majority of matt variants contain at least two antigens related to type-specificity and designated as M and T (1). In a preceding paper, a new method of separating these two antigens was described (2). It was found that short exposure of group A streptococci to the action of proteotytic enzymes destroyed the M substance but left the T substance apparently analtered. In most instances, therefore, immunization of rabbits with enzymetreated streptococci led to the production of T antibodies. In the case of certain strains, however, the injection of suspensions so treated failed to induce the formation of T antibodies.

No abstract

No abstract

Most investigators who have used the slide agglutination technique for typing group A hemolytic streptococci have found particular difficulty in distinguishing certain apparently closely related strains. Griffith, in 1934, described a "group agglutination" among types 15, 17, and 18 (1). Other workers have reported difficulty in distinguishing types included in this study (2)(3)(4)(5)(6)(7)(8). By means of the precipitin reaction, however, these types are readily differentiated on the basis of the type-specific M substance.In this laboratory, agglutination experiments have shown that types 15, 17, 19, 23, and 30 compose a series of related types, and that members of a second series comprising types 4, 24, 26, 28, 29, and 46 are also closely related.Previous study of the relationship of strain C 203 to type 1 demonstrated that strains which contained distinct M antigens might, nevertheless, give cross agglutination due to a common T antigen (9). This finding suggested that, since the M antigens of the types concerned in the present investigation were distinct, similar T antigens might be responsible for the cross agglutination observed among these types. Experiments were undertaken to test this hypothesis.

No abstract