The Extra Cytoplasmic Function Sigma Factor σE Is Essential for Mycobacterium tuberculosis Virulence in Mice

The virulence of a Mycobacterium tuberculosis H37Rv sigE mutant was studied in immunodeficient and immunocompetent mice. The mutant was strongly attenuated in both animal models and induced formation of granulomas with different characteristics than those induced by the wild-type strain.