Serological classification of Bacteroides gingivalis and purification of group specific antigens.

Bacteroides gingivalis were serologically investigated by the immunodiffusion technique using autoclave-extracted antigens and antisera against whole cells. Fifteen strains of B. gingivalis used in this study, were classified in two distinct serological groups. Eleven strains include strain 381, ATCC 33277 were classified Group A and four strains include strain Su63 were classified in Group B. The group specific antigens from B. gingivalis strain 381 (Group A) and Su63 (Group B) were partially purified from autoclave extracts by 75% ethanol precipitation and anion exchange chromatography, and were identified as polysaccharides composed of glucose (82.3%, 23.7%), rhamnose (7.1%, 12.7%), galactose (4.9%, 18.2%), mannose (2.3%, 1.7%), glucosamine (0.4%, 28.0%) and galactosamine (3.0%, 15.3%).