title: Colonial opacity variations among the choleragenic vibrios.
abstract: Cultures of Vibrio cholerae 01, biotype El Tor, from the current epidemic of cholera in the Western Hemisphere, and of the new V. cholerae serogroup O139, from the current outbreak in India and Bangladesh, revealed marked colonial heterogeneity when received by the authors. By comparison with reference colony types, using a stereoscope and transmitted oblique illumination, colonies of approximately 10 different degrees of opacity could be distinguished. In contrast, strains freshly isolated from patients and rapidly and carefully preserved were more homogeneous although still differentiable by this technique. These (and older) observations prompted the questions: (1) why is a V. cholerae colony opaque or translucent? and (2) what benefit is it to the vibrios to vary their colonial appearance? The observed changes in colonial opacity, which are reversible, are sometimes (rarely) accompanied by changes in virulence for infant rabbits and, more frequently, by other phenotypic variations including the ability to produce poly-beta-hydroxybutyrate inclusion bodies on glycerol-containing medium, the degree of encapsulation in 0139, changes in outer-membrane proteins, alteration in lipopolysaccharide structure, changes in expression of glycolytic pathways, and differences in ability to survive under adverse conditions. Colonial variations in choleragenic vibrios are phenotypically multifactorial. The genetic mechanisms(s) underlying the observed phenotypic changes remain to be defined.
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Finkelstein
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Boesman-Finkelstein
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
authors.forename: Dilip K
authors.initials: DK
authors.lastname: Sengupta
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9.
authors.forename: William J
authors.initials: WJ
authors.lastname: Page
authors.affiliation: Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Stanley
authors.affiliation: Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Phillips
mesh_terms: D000569:Americas; D000818:Animals; D016667:Bacterial Capsules; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001459:Bangladesh; D002771:Cholera / Q000382:microbiology*; D004196:Disease Outbreaks; D018740:Genetic Heterogeneity; D006801:Humans; D006885:Hydroxybutyrates / Q000032:analysis; D007091:Image Processing, Computer-Assisted; D007194:India; D011091:Polyesters / Q000032:analysis; D011817:Rabbits; D014734:Vibrio cholerae / Q000472:pathogenicity / Q000648:ultrastructure*; D000094122:Polyhydroxybutyrates
chemical_list: D001425:Bacterial Outer Membrane Proteins; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates