A defined O-antigen polysaccharide mutant of Francisella tularensis live vaccine strain has attenuated virulence while retaining its protective capacity.

ABSTRACT: Francisella tularensis, the causative agent of tularemia, has been designated a CDC category A select agent because of its low infective dose (<10 CFU), its ready transmission by aerosol, and its ability to produce severe morbidity and high mortality. The identification and characterization of this organism's virulence determinants will facilitate the development of a safe and effective vaccine. We report that inactivation of the wbtA-encoded dehydratase of the O-antigen polysaccharide (O-PS) locus of the still-unlicensed live vaccine strain of F. tularensis (LVS) results in a mutant (the LVS wbtA mutant) with remarkably attenuated virulence. Western blot analysis and immune electron microscopy studies associate this loss of virulence with a complete lack of surface O-PS expression. A like

SUBMITTER: Sebastian S 

PROVIDER: S-EPMC1865767 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature