Antigens of Streptococcus sanguis: purification and characterization of the b antigen

Abstract

The antigen defining Streptococcus sanguis serotype 2 has been designated the b antigen. This antigen can be detected in extracts, obtained from whole cells by autoclaving (Rantz and Randall extraction), as a single precipitin band using a reference antiserum (M-5). However, the extract can also be shown to contain a teichoic acid using anti-polyglycerol phosphate serum. This teichoic acid does not contain the antigenic determinant for group H specificity. Studies of the b antigen have been hampered because of the difficulty in separating the b antigen from the teichoic acid using ion-exchange and molecular sieve chromatography. However, a relatively pure preparation has been obtained by affinity chromatography using anti-polyglycerol phosphate serum coupled to Sepharose. The isolated b antigen is a typical streptococcal cell wall polysaccharide composed of glucose, rhamnose, and N-acetylglucosamine in a molar ratio of 2.5:1.0:0.1. The antigen appears to have a single antigenic determinant closely related to isomaltose (glucose a-1,6-glucoside) based upon hapten inhibition studies. MATERIALS AND METHODSOrganisms. S. sanguis ATCC 10556 was the principal organism used in this study; stock cultures were maintained at -70°C in brain heart infusion (Difco) broth. S. sanguis M-5 and Lactobacillus casei L324M were used for production of the group-specific (group H, M-5) and anti-polyglycerolphosphate (PGP) serum, 896 on August 5, 2020 by guest http://iai.asm.org/ Downloaded from INFECT. IMMUN. on August 5, 2020 by guest http://iai.asm.org/ Downloaded from

Purification and immunochemical characterization of Streptococcus sanguis serotype I carbohydrate antigen

“…The immunodeterminant of this antigen was most likely terminal a-linked glucosidic bonds. A similar antigen (b antigen) has been obtained from S. sanguis ATCC 10556 by Appelbaum and Rosan (1). They prepared the antigen by hot saline extraction of whole cells of ATCC 10556, which is a reference strain of serotype I S. sanguis.…”

Antigenic determinant of the Lancefield group H antigen of Streptococcus sanguis

“…(ca. 5-by 7.5-cm) glass plates coated with 12 ml of agarose containing group H or anti-teichoic acid serum at a final dilution of 1/50 in a barbital buffer (2). Electrophoresis was carried out at 3 V/cm; this system could detect 0.1 ,ug of teichoic acid per ml with either antiserum.…”