Virulence properties of type VII Streptococcus agalactiae (group B streptococci) and immunochemical analysis of capsular type polysaccharide.
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.
VON Hunolstein
Christina
C
Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
Parisi
Laura
L
Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
Tissi
Luciana
L
Servizio Biologico, Istituto Superiore di Sanità, Rome, Italy.
Recchia
Simona
S
Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
Alfarone
Giovanna
G
Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
Nicolini
Laura
L
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Volpe
Corrado
C
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Wagner
Barbara
B
Institute of Experimental Microbiology, F. Schiller University, Jena, Germany.
Motlova
Jitka
J
National Institute of Public Health, Prague, Czech Republic.
Orefici
Graziella
G
Laboratorio di Batteriologia e Micologia Medica, Rome, Italy.
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
D007106:Immune Sera; D011135:Polysaccharides, Bacterial; D019158:N-Acetylneuraminic Acid