Chemical composition and immunological specificity of cell wall polysaccharide group antigens of streptococcal groups P and U.

The group antigens of streptococcal groups P and U were extracted with formamide and purified on diethylaminoethyl-Sephadex A-25 and Sephadex G-200. The antigens were shown to be polysaccharides located in the cell walls of the organisms. In a precipitin test, the P and U group antigens did not cross-react with homologous sera of each other, nor with specific antiserum of the group antigen of group E streptococci. The polysaccharide comprising the group P antigen contained rhamnose, glucose, galactose, glucosamine, and galactosamine; the group U antigen was similar in composition but lacked galactosamine and contained more galactose.