Variation of type Antigens of Group-B Streptococci

Abstract
Serological typing of Group-B streptococci isolated on different occasions during the course of natural intramammary infections revealed no shifts between polysaccharide types, but showed that polysaccharide antigens and the protein Ibc antigen may be lost and regained. Pure X-strains may arise from strains previously typed as IIIX or III, or from non-typeable strains, and possibly from Ibc, Ia and Ib strains as well. Such strains may later revert to their original types.