The PhoP-PhoQ two-component regulatory system of Photorhabdus luminescens is essential for virulence in insects.

ABSTRACT: Photorhabdus luminescens is a symbiont of entomopathogenic nematodes. Analysis of the genome sequence of this organism revealed a homologue of PhoP-PhoQ, a two-component system associated with virulence in intracellular bacterial pathogens. This organism was shown to respond to the availability of environmental magnesium. A mutant with a knockout mutation in the regulatory component of this system (phoP) had no obvious growth defect. It was, however, more motile and more sensitive to antimicrobial peptides than its wild-type parent. Remarkably, the mutation eliminated virulence in an insect model. No insect mortality was observed after injection of a large number of the phoP bacteria, while very small amounts of parental cells killed insect larvae in less than 48 h. At the molecular level,

SUBMITTER: Derzelle S 

PROVIDER: S-EPMC344422 | biostudies-literature | 2004 Mar

REPOSITORIES: biostudies-literature