CTXphi immunity: application in the development of cholera vaccines.

ABSTRACT: CTXphi is a filamentous bacteriophage that encodes cholera toxin, the principal virulence factor of Vibrio cholerae. CTXphi is unusual among filamentous phages because it encodes a repressor and forms lysogens. CTXphi can infect the existing live-attenuated V. cholerae vaccine strains derived from either the El Tor or classical V. cholerae biotypes and result in vaccine reversion to toxinogenicity. Intraintestinal CTXphi transduction assays were used to demonstrate that El Tor biotype strains of V. cholerae are immune to infection with the El Tor-derived CTXphi, whereas classical strains are not. The El Tor CTXphi repressor, RstR, was sufficient to render classical strains immune to infection with the El Tor CTXphi. The DNA sequences of the classical and El Tor CTXphi repressors and their

SUBMITTER: Kimsey HH 

PROVIDER: S-EPMC22729 | biostudies-literature | 1998 Jun

REPOSITORIES: biostudies-literature