The Brucella abortus Cu Zn Superoxide Dismutase Is Required for Optimal Resistance to Oxidative Killing by Murine Macrophages and Wild-Type Virulence in Experimentally Infected Mice

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Jason Gee (Creator)

Vanessa Grippe (Creator)

Michael Kovach (Creator)

Wai-Leung Ng (Creator)

John Richardson (Creator)

Gregory Robertson (Creator)

Martin II Roop (Creator)

Michelle Valderas (Creator)

Malcolm Winkler (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Two-dimensional gel electrophoretic analysis of cell lysates from Brucella abortus 2308 and the isogenic hfq mutant Hfq3 revealed that the RNA binding protein Hfq (also known as host factor I or HF-I) is required for the optimal stationary phase production of the periplasmic Cu Zn superoxide dismutase SodC. An isogenic sodC mutant designated MEK2 was constructed from B. abortus 2308 by gene replacement and the sodC mutant exhibited much greater susceptibility to killing by O2 generated by pyrogallol and the xanthine oxidase reaction than the parental 2308 strain supporting a role for SodC in protecting this bacterium from O2 of exogenous origin. The B. abortus sodC mutant was also found to be much more sensitive to killing by cultured resident peritoneal macrophages from C57BL6J mice than 2308 and the attenuation displayed by MEK2 in cultured murine macrophages was enhanced when these phagocytes were treated with gamma interferon (IFN- ). The attenuation displayed by the B. abortus sodC mutant in both resting and IFN- - activated macrophages was alleviated however when these host cells were treated with the NADPH oxidase inhibitor apocynin. Consistent with its increased susceptibility to killing by cultured murine macrophages the B. abortus sodC mutant also displayed significant attenuation in experimentally infected C57BL6J mice compared to the parental strain. These experimental findings indicate that SodC protects B. abortus 2308 from the respiratory burst of host macrophages. They also suggest that reduced SodC levels may contribute to the attenuation displayed by the B. abortus hfq mutant Hfq3 in the mouse model. Originally published in Infection and Immunity Vol. 73 No. 5.

Additional Information

Publication

Other

INFECTION AND IMMUNITY May 2005 p. 2873–2880

Language: English

Date: 2011

Keywords

Brucella abortus, RNA binding protein, isogenic mutants

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