Salmonella pathogenicity island 2-dependent evasion of the phagocyte NADPH oxidase.

A Vazquez-Torres, Y Xu, J Jones-Carson, D W Holden, S M Lucia, M C Dinauer, P Mastroeni, F C Fang

Index: Science 287(5458) , 1655-8, (2000)

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Abstract

A type III protein secretion system encoded by Salmonella pathogenicity island 2 (SPI2) has been found to be required for virulence and survival within macrophages. Here, SPI2 was shown to allow Salmonella typhimurium to avoid NADPH oxidase-dependent killing by macrophages. The ability of SPI2-mutant bacteria to survive in macrophages and to cause lethal infection in mice was restored by abrogation of the NADPH oxidase-dependent respiratory burst. Ultrastructural and immunofluorescence microscopy demonstrated efficient localization of the NADPH oxidase in the proximity of vacuoles containing SPI2-mutant but not wild-type bacteria, suggesting that SPI2 interferes with trafficking of oxidase-containing vesicles to the phagosome.