Rescue of an intracellular avirulent Rhodococcus equireplication defect by the extracellular addition of virulence-associated proteinA

[摘要] Rhodococcus equi is a facultative intracellular bacterium that canescape from bactericidal mechanisms associated with phagocytosis. Virulence-associatedprotein A (VapA), encoded on a virulence-associated plasmid, is essential forintracellular survival in macrophages, but its function is not known. Here, we show thatthe extracellular addition of recombinant glutathione S-transferase (GST)-VapA fusionprotein rescued the intracellular replication defect of a mutant lacking thevapA gene. Furthermore, the virulence-plasmid-cured strain could alsomultiply to nearly wild-type levels by the addition of GST-VapA. The present data suggestthat VapA can alter the intraphagocytic environment, thereby affecting its suitability forthe growth of R. equi.

[学科分类] 兽医学

[关键词] intracellular growth;Rhodococcus equi;VapA