Journal of Microbiology

Research Support, Non-U.S. Gov'ts

NOTE] Comparative Assessment of the Intracellular Survival of the Burkholderia pseudomallei bopC Mutant: Varintip Srinon , Sunsiree Muangman , Nithima Imyaem , Veerachat Muangsombut , Natalie R. Lazar Adler , Edouard E. Galyov , Sunee Korbsrisate; J. Microbiol. 2013;51(4):522-526. Published online August 30, 2013; DOI: https://doi.org/10.1007/s12275-013-2557-3

Abstract: Burkholderia pseudomallei, the causative agent of melioidosis, is a Gram-negative saprophytic bacterium capable of surviving within phagocytic cells. To assess the role of BopC (a type III secreted effector protein) in the pathogenesis of B. pseudomallei, a B. pseudomallei bopC mutant was used to infect J774A.1 macrophage-like cells. The bopC mutant showed significantly reduced intracellular survival in infected macrophages compared to wild-type B. pseudomallei. In addition, the bopC mutant displayed delayed escape from endocytic vesicles compared with the wild-type strain. This indicates that BopC is important, and at least in part, needed for intracellular survival of B. pseudomallei.

Expression and Characterization of an Iron-Containing Superoxide Dismutase from Burkholderia pseudomallei: Min-Hee Cho , Yong-Woo Shin , Jeong-Hoon Chun , Kee-Jong Hong , Byoung-Kuk Na , Gi-eun Rhie , Baik-Lin Seong , Cheon-Kwon Yoo; J. Microbiol. 2012;50(6):1029-1033. Published online December 30, 2012; DOI: https://doi.org/10.1007/s12275-012-2267-2

Abstract: A superoxide dismutase (SOD) gene from Burkholderia pseudomallei, the causative agent of melioidosis, was cloned and expressed in Escherichia coli, and its product was functionally and physically characterized. The gene has an open-reading frame of 579 bp. The deduced amino acid sequence has 192 residues with a calculated molecular mass of ~22 kDa. Sequence comparison with other bacterial SODs showed that the protein contains typical metal-binding motifs and other Fe-SOD-conserved residues. The sequence has substantial similarity with other bacterial Fe-SOD sequences. The enzymatic activity of the expressed protein was inhibited by hydrogen peroxide but not by sodium azide or potassium cyanide, attributes that indeed are characteristic of typical bacterial Fe-SODs. Western blotting with antiserum against the recombinant Fe-SOD revealed that it is expressed in B. pseudomallei. Transformed E. coli that expressed the Fe-SOD had significantly increased SOD activity and was highly tolerant to paraquat-mediated replication inhibition, compared to transformed cells carrying an empty vector. Our results provide a basis for further biochemical characterization of the enzyme and elucidation of its role in the pathogenesis of B. pseudomallei.

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