[Biological properties of Streptococcus group B: the interrelations of the virulence in mice, the adhesion to human epithelial cells and the production of type-specific antigen].

The results presented in this work confirm the possibility of selecting the subpopulations of group B streptococci by the passage of these microorganisms through mice. This process was accompanied by the accumulation of cells with a high level of type-specific antigen (TSA). The passage of group B streptococci in the presence of type-specific antibodies led to the selection of avirulent microorganisms with low TSA production and high adhesiveness. These data may be considered to be the indirect evidence of the screening effect of TSA contained in the capsule of group B streptococci with respect to the ligand structures of these microbes. This suggestion is confirmed by the behavior of the variants of group B streptococci, obtained in the course of this investigation, on virus-infected tissue when TSA+ strains lost their ability to recognize viral polypeptides serving as receptors for TSA- variants of the streptococci.