THE SALMONELLA-TYPHIMURIUM FLGM GENE, WHICH ENCODES A NEGATIVE REGULATOR OF FLAGELLA SYNTHESIS AND IS INVOLVED IN VIRULENCE, IS PRESENT ANDFUNCTIONAL IN OTHER SALMONELLA SPECIES

FlgM inhibits the flagella-specific sigma factor FliA and is involved in the mouse-virulence of Salmonella typhimurium. In recent experiment s, we observed that: (i) a flgM gene that could function to negatively regulate flagella synthesis was present in a variety of salmonellae; and (ii) the flgM gene derived from Salmonella species that are not no rmally virulent in mice could complement the S. typhimurium flgM mutan t for virulence. Our results suggest that a functional flgM has been r etained in most, and perhaps all, Salmonella species, regardless of th e motility or virulence phenotype of the strain.