title: The vir locus and phase-variation in Bordetella pertussis.
abstract: By a phenomenon known as phase-variation Bordetella pertussis is capable of changing between a virulent-phase in which multiple virulence-associated determinants are expressed, and an avirulent-phase in which the virulence-associated determinants are not expressed. Mutations in the vir locus of B. pertussis have a similar effect. We have examined the state of the vir locus in each of a series of strains derived one from the other by phase-variation. We have found that a single base-pair change is associated with the change between the virulent and avirulent phases. This single base-pair change corresponds to a frameshift mutation in the vir locus.
authors.affiliation: Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD.
authors.forename: S
authors.initials: S
authors.lastname: Stibitz
authors.forename: W
authors.initials: W
authors.lastname: Aaronson
authors.forename: D
authors.initials: D
authors.lastname: Monack
authors.forename: S
authors.initials: S
authors.lastname: Falkow
mesh_terms: D001886:Bordetella pertussis / Q000235:genetics* / Q000472:pathogenicity; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D009154:Mutation; D014774:Virulence / Q000235:genetics
chemical_list: D004269:DNA, Bacterial