Isolation and immunochemical characterization of carbohydrate antigens prepared from group A Streptococcus pyogenes.

Group A carbohydrate antigens were prepared from isolated cell walls or whole cells of Streptococcus pyogenes strain Sv (group A, M type 3). Cell walls were lysate by the enzymatic action of M1 endo-N-acetylmuramidase. The cell wall lysate was concentrated and chromatographed on a Sephadex G-100 column. Two fractions reactive with group A antisera were obtained. These were composed of N-acetylglucosamine, rhamnose, and peptidoglycan components such as glutamic acid, lysine, alanine, N-acetylmuramic acid and N-acetylglucosamine. For comparison, hot TCA extract of the cell walls (TCAgA) or Rantz and Randall extract of the whole cells (RRgA) was purified chromatographically. The latter two also contained rhamnose and glucosamine, and were reactive with group A antisera. The molecular weights of M1gA antigens were larger than those of TCAgA and RRgA. Hapten inhibition study indicated that N-acetylglucosamine was the most potent inhibitor.