title: Virulence properties of type VII Streptococcus agalactiae (group B streptococci) and immunochemical analysis of capsular type polysaccharide.
abstract: Strains of a new polysaccharide type of group B streptococci (GBS), type VII, have been isolated from human carriers and invasive infections. Some of these strains bear the protein antigen c or R, as do other GBS serotypes. The capsular type polysaccharide is sialylated and this residue is involved in the immunodeterminant structure. All type VII strains examined were virulent in CD-1 mice; the LD50 after intraperitoneal (i.p.) challenge was 4.57 (SD 0.12) x10(7) cfu for the reference strain and 5.49 (SD 1.5) x10(7) cfu for clinical isolates. A particular feature of this serotype was the ability to induce septic arthritis not only when injected intravenously (i.v.), but also when injected i.p. Rabbit antiserum against the capsular type VII polysaccharide exhibited opsonic activity in a phagocytosis assay and protective activity against infection.
authors.affiliation: Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
authors.forename: Christina
authors.initials: C
authors.lastname: VON Hunolstein
authors.affiliation: Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Parisi
authors.affiliation: Servizio Biologico, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Tissi
authors.affiliation: Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Recchia
authors.affiliation: Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Alfarone
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Nicolini
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Volpe
authors.affiliation: Institute of Experimental Microbiology, F. Schiller University, Jena, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wagner
authors.affiliation: National Institute of Public Health, Prague, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Motlova
authors.affiliation: Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
authors.forename: Graziella
authors.initials: G
authors.lastname: Orefici
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001170:Arthritis, Infectious / Q000382:microbiology*; D016667:Bacterial Capsules / Q000737:chemistry / Q000276:immunology*; D003429:Cross Reactions; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D051379:Mice; D016253:Microscopy, Immunoelectron; D019158:N-Acetylneuraminic Acid / Q000032:analysis; D010587:Phagocytosis; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology*; D011817:Rabbits; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000276:immunology / Q000472:pathogenicity* / Q000648:ultrastructure; D014774:Virulence
chemical_list: D007106:Immune Sera; D011135:Polysaccharides, Bacterial; D019158:N-Acetylneuraminic Acid