Immunochemical Analysis of Streptococcus bovis, Strain s19, Cell Walls

SUMMARY Two antigens, a glucose-rich capsular polymer and a cell wall carbohydrate consisting of N-acetylglucosamine, glucose and rhamnose, were isolated from Streptococcus bovis, strain s 19. N-acetylglucosamine and a haptenic fraction rich in glucosamine inhibited approximately 56 and 63% of the quantitative precipitin reaction between the s 19 cell wall carbohydrate and its homologous antiserum, respectively. A cross-reactivity between a preparation of azo-protein, which consisted of terminal β-N-acetylglucosaminide residues, and s 19 antiserum substantiated the fact that N-acetylglycosamine is one of the major antigenic determinants of the s 19 cell-wall carbohydrate. Haptenic inhibition studies have not revealed any structural feature of the antigenic determinant of the glucose-rich capsular polymer.