Immunochemical studies on the group and type antigens of group F streptococci and the identification of a grouplike carbohydrate in a type II strain with an undesignated group antigen.

Two antigens, the group-specific carbohydrate and the Type II carbohydrate, have been isolated by cellulose column chromatography from a formamide extract of a Group F streptococcus. Chemical and immunologic analyses indicate that both antigens are free of other cellular components. Both antigens are components of the cell wall although the Type II antigen is probably more superficial than the group antigen. The Type II antigen is composed of rhamnose, glucose, galactose, and galactosamine. The Group F antigen is composed of rhamnose, glucose, galactosamine and a small percentage of glucosamine. A grouplike carbohydrate and the Type II carbohydrate have been isolated from a streptotoccal strain which lacks a serologically detectable streptococcal group antigen. This grouplike carbohydrate, which does not cross-react immunologically with Group F serum, is composed of rhamnose, galactose, and glucosamine. No chemical or immunological differences were observed between the Type II antigen isolated from the Group F strain and the Type II antigen isolated from the nongroupable strain.