Interaction of wheat-germ agglutinin with streptococci and streptococcal cell wall polymers

Wheat-germ agglutinin agglutinates all strains of group A and group C streptococci, a part of the strains tested of groups B and E and some strains of other streptococcal groups. It also agglutinates peptidoglycan of several streptococcal groups and precipitates some group-specific carbohydrates of streptococcal cell walls as well as some teichoic acid extracts. The basis for agglutination and precipitation of streptococci and streptococcal cell wall polymers appears to be the interaction of the combining sites of the agglutinin with N-acetyl-D-glucosamine residues present in the cell wall polymers, either in terminal or in internal positions respectively.