Group A Streptococcal Polysaccharide Antigens

Abstract

Cold trichloroacetic acid extracts of group A, type 3 streptococci were fractionated on Sephadex G50 and ECTEOLA cellulose columns. A glucose- N -acetylglucosamine polymer was isolated and shown by chemical, electrophoretic, and antigenic analysis to be distinct from the group A polysaccharide. The antigenic specificity was due to the glucosamine. A glycerol-phosphate-alanine-glucosamine teichoic acid polymer was isolated. The antigenic specificity was due to N -acetylglucosamine and d -alanine methyl ester, with the former possessing principal responsibility. The glucosamine and ester-linked alanine appear to be labile to the method of extraction and fractionation. Group A streptococcal whole cell antiserum, after adsorption with cells of a heterologous serological group and group A polysaccharide antigen, contained antibodies against both polymers.