title: [Correlation between the virulence of streptococci for mice and their IgG FcR activity in in vivo experiments].
abstract: The immunological analysis of 24 spontaneous Strr, Rifr and Kanr mutants of streptococcal strain IP, highly virulent for mice and capable of binding polyclonal human IgG (IgG FcR+), was made. The characteristic feature of all these mutants was decreased virulence, restored after their passage in vivo. 23 mutants were capable of binding polyclonal IgG; one Strr mutant had no such capacity, but acquired it, together with an increase in virulence, after its passage in vivo. When stored in meat-peptone agar without antibiotics, 5 out of 10 Strr mutants lost their capacity for binding polyclonal human IgG. After passage in vivo they regained this property simultaneously with virulence.
authors.forename: E I
authors.initials: EI
authors.lastname: Katser
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors; D004352:Drug Resistance, Microbial; D007074:Immunoglobulin G / Q000276:immunology*; D051379:Mice; D009154:Mutation; D011961:Receptors, Fc / Q000276:immunology*; D017452:Receptors, IgG; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG
vernacular_title: Korreliatsiia mezhdu virulentnost'iu streptokokkov dlia mysheĭ i IgG FcR-aktivnost'iu v opytakh in vivo.