Vibrio cholerae mutants which are soft-agar penetration defective and lack a functional CtxA subunit
AssigneePresidents and Fellows of Harvard College
InventorsJohn J. Mekalanos, Claudette L. Gardel, Andrew Camilli
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Abstract
V. cholerae vaccine strains which have a soft agar penetration-defective phenotype and methods for making such strains are described. Also described are methods for identifying new genes involved in V. cholerae motility and the cloning, identification, and sequencing of V. cholerae motB and fliC genes.
Claims26
A genetically stable vaccine comprising a nontoxinogenic genetically stable mutant strain of Vibrio cholerae, said mutant strain being a mutan:
- of a parental strain, said mutant strain comprising a deletion ot DNA encoding the CtxA subunit such that said strain lacks a subunit A of cholera toxin, and said mutant strain further exhibiting a soft agar penetration-defective phenotype relative to said parental strain wherein said vaccine is in a physiologically acceptable carrier.
A genetically stable vaccine comprising a nontoxinogenic genetically stable mutant strain of Vibrio cholerae, said mutant strain being a mutant of a parental strain, said mutant strain comprising a deletion of DNA encodine the CtxA subunit such that said strain lacks a reactogenic subunit A of cholera toxin, wherein at least 25% of the cells of said strain are capable of forming filamentous structures of 15 nM or greater under conditions of stationary phase growth wherein said vaccine is in a physiologically acceptable carrier.
A method of making a killed Vibrio cholerae vaccine, said method comprising the steps of
- providing at least one mutant strain exhibiting a soft agar penetration-defective phenotype, which strain has been killed;
- adding to said killed strain cholerae toxin B subunit produced by said strain wherein said toxin B subunit is obtained from the medium in which said strain was propagated;
- and
- suspending said killed strains and said toxin B subunit in a physiologically acceptable carrier.
Dependencies are inferred from the claim text.