Brucella melitensis mutants and methods

Abstract

Certain attenuated mutants of Brucella, especially B. melitensis, B. abortus, B. suis and B. ovis, when administered to a human or animal trigger a protective immune response such that subsequent challenge with virulent Brucella of the same species does not result in disease or results in much less severe symptoms. Functional inactivation of galE, a virB gene or the operon (ORFs 1087-1090) comprising the gene encoding β-hexosaminidase (BMEI1087) and a lytic murein transglycosylase gene (BMEI1088). A specific example of the attenuated galE mutant which produces a protective immune response is B. melitensis GR024. The specific example of an inactivated ORF1087-1090 operon is B. melitensis GR026; it has an insertion mutation in the promoter region upstream of ORF 1090. Vaccination with live cells of either or both of these mutants results in a T cell response which protects the human or animal against challenge with virulent B. melitensis. Similar strategies for protective immunity using live attenuated mutants are useful for B. abortus, B. suis and B. ovis as well.

Dependencies are inferred from the claim text.