title: Correlation of the polysaccharide antigens of Francisella tularensis with virulence in experimental mice.
abstract: Francisella tularensis gives rise to two distinct colony types, acriflavine agglutination test-positive (acf+) and -negative (acf-) colonies. The acf+ variants were exclusively low virulent in mice, while the acf- variants were shown to be either high or low virulent. Three fractions, phosphate-buffered saline-extractable without heating, with heating at 60 C, and with heating at 100 C, were obtained from cultures of both the acf+ and acf- variants on agar media, and the polysaccharide antigens in those fractions were quantitated. All of the highly virulent acf- variants possessed a large amount of the polysaccharide antigen in the fraction extractable with heating at 60 C. This antigen was not, however, detected in any of the acf+ variants and one low-virulent acf- variant. It was also detected in a very low amount in some other acf- variants with low virulence. The amount of this polysaccharide antigen was therefore shown to be correlated with bacterial virulence in mice.
authors.affiliation: Ohara Research Laboratory, Fukushima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fujita
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Ohara
authors.forename: M
authors.initials: M
authors.lastname: Homma
mesh_terms: D000167:Acriflavine / Q000494:pharmacology; D000372:Agglutination Tests; D000818:Animals; D000942:Antigens, Bacterial / Q000302:isolation & purification; D005604:Francisella tularensis / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity*; D006358:Hot Temperature; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D014774:Virulence / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; D000167:Acriflavine