Relation Between Encapsulation of Streptococl of Serological Geroup B and Adherence Properties of The Bacteria To Deae-Sephacel

Abstract

Determination of surface charge of group B streptococci by ~ o nex change chromatography on DEAE-Sephacel revealed that bovine and human group B streptococcal isolates with protein c-xface antigens alone, or bacteria with protein ant~genin combination with polysacharide antigens, adhered strongly to the gel matrix. In contrary, cultures with polysaccharide antigens alone showed no comparable adherence properties. Removal of neuraminic acid ffom bacterial surface enhanced, but pronase treatment reduced the adherence values. The importance of type specific capsular sialylation for group B streptococcal surface charge could be confirmed with group B streptococci of serotype 111 and their transposon mutagenized asialocapsular mutants. In contrary to the encapsulated parent strains the asialo capsular mutants adhered strongly to the gel matrix. Comparable differences were observed with unencapsulated group B streptococcal variant strains and its isogenic encapsulated parent strains. The capsule material seemed to mask the surface proteins responsible for the adherence to the gel matrix. The determlnation of surface charge of group B streptococci by ionexchange chromatography might help to understand the importance of capsular sialylation for individual isolates of this bacterial species.