Rhodococcus equi virulence-associated protein A is required for diversion of phagosome biogenesis but not for cytotoxicity.

ABSTRACT: Rhodococcus equi is a gram-positive facultative intracellular pathogen that can cause severe bronchopneumonia in foals and AIDS patients. Virulence is plasmid regulated and is accompanied by phagosome maturation arrest and host cell necrosis. A replacement mutant in the gene for VapA (virulence-associated protein A), a major virulence factor of R. equi, was tested for its activities during macrophage infection. Early in infection, phagosomes containing the vapA mutant did not fuse with lysosomes and did not stain with the acidotropic fluor LysoTracker similar to those containing virulent wild-type R. equi. However, vapA mutant phagosomes had a lower average pH. Late in infection, phagosomes containing the vapA mutant were as frequently positive for LysoTracker as phagosomes containing plas

SUBMITTER: von Bargen K 

PROVIDER: S-EPMC2786453 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature