Beta-hemolytic Streptococci with Group a and Type Ii Carbohydrate Antigens.

Jablon, James M. (National Children's Cardiac Hospital, Miami, Fla.), Betty Brust, and Milton S. Saslaw. beta-Hemolytic streptococci with group A and type II carbohydrate antigens. J. Bacteriol. 89:529-534. 1965.-Ten strains of beta-hemolytic streptococci with unusual somatic antigens were isolated from excised tonsils or throat cultures or both. Acid extracts of these strains reacted with commercial group A and group F antisera, but gave no reaction when tested with 35 type-specific group A antisera. Serum cross-absorption and agar-gel diffusion studies established the identity of the reactive antigens as the specific carbohydrates of group A and of type II. The latter antigen has been found in many strains of group F streptococci. The organisms do not possess the group-specific carbohydrate of group F, and the reaction with the commercial group F antiserum is due to the presence of type II antibody in the antiserum. The organisms give a stronger reaction to fluorescein-conjugated type II antiserum than to group A. However, the organisms have only one group-specific carbohydrate, that of group A, and, tentatively, should be classified as such.