title: Strain specificity of opsonins for group B streptococci types II and III.
abstract: Strains of types II and III group B streptococci do not appear to be uniformly susceptible to opsonization by antibody-containing human sera, as studied using both a chemiluminescence and a radiolabeled bacterial uptake technique. We could not demonstrate a correlation of serum-sensitive or resistant strains with capsular antigen quantities, although serum absorption studies with whole organisms and HCl, trichloroacetic acid, and saline extracts indicated that the antibody to type-specific capsular polysaccharide is important in opsonizing both serum-resistant and serum-sensitive strains. Since trypsin treatment produced significantly enhanced opsonization of serum-resistant and serum-sensitive strains, proteins present on some group B streptococci may be important antiphagocytic factors.
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D009895:Opsonin Proteins / Q000276:immunology*; D010587:Phagocytosis; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013045:Species Specificity; D013292:Streptococcus agalactiae / Q000276:immunology*; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D009895:Opsonin Proteins; D011135:Polysaccharides, Bacterial; D014357:Trypsin