title: [The isolation and characteristics of variant plague microbes not producing the capsular antigen].
abstract: Fifteen stable variants of Yersinia pestis strains exhibiting different degrees of virulence for white mice and guinea pigs were obtained. Multiple passages of the organisms at 37 degrees C in a fluid nutrient medium containing antiplague agglutinating serum were found to be the most efficient method for obtaining noncapsular forms of the plague agent. Acquisition of the Fra(-) phenotype both by wild and laboratory strains was not associated with a loss of the high-molecular plasmid by cells but was probably a result of mutational alterations in the plasmid genes.
authors.forename: N A
authors.initials: NA
authors.lastname: Gvozdenko
authors.forename: V Iu
authors.initials: VIu
authors.lastname: Ryzhkov
authors.forename: N V
authors.initials: NV
authors.lastname: Pavlovich
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D001431:Bacteriological Techniques; D014644:Genetic Variation / Q000276:immunology*; D006168:Guinea Pigs; D051379:Mice; D010641:Phenotype; D012692:Serial Passage; D014774:Virulence / Q000276:immunology; D015010:Yersinia pestis / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D000942:Antigens, Bacterial
vernacular_title: Poluchenie i kharakteristika variantov chumnogo mikroba, ne produtsiruiushchikh kapsul'nogo antigena.