title: Downregulation of Na(+)-NQR complex is essential for Vibrio alginolyticus in resistance to balofloxacin.
abstract: Increasingly isolated frequency of antibiotic-resistant V. alginolyticus strains in clinic and aquaculture has been reported, but the mechanisms of V. alginolyticus antibiotic resistance are largely absent. In the present study, native/SDS-PAGE based proteomics, which may provide information on protein-protein interaction, was utilized to investigate differential proteins of V. alginolyticus in resistance to balofloxacin. Ten proteins were altered, in which V12G01_04671, V12G01_00457, V12G01_15927, V12G01_15240, NqrA (spot 26), and NqrF (spot 30) were downregulated, while V12G01_22043, TolC, V12G01_15130, V12G01_19297 were upregulated. Importantly, the two components of Na(+)-NQR complex, NqrA and NqrF, were vertically lined and was further investigated. Western blotting assay indicated that downregulation of the two proteins contrasted sharply with upregulation of a control protein TolC, which was consistent with the result obtained from 2-DE gel analysis. Furthermore, overexpression of NqrA, NqrF and TolC resulted in decrease and elevation of bacterial survival ability in medium with balofloxacin, respectively. These results indicate that downregulation of Na(+)-NQR complex is essential for V. alginolyticus resistance to balofloxacin. This is the first report on the role of Na(+)-NQR complex in antibiotic resistance. This finding highlights the way to an understanding of antibiotic-resistant mechanisms in content of metabolic regulation.
authors.affiliation: Center for Proteomics, State Key Laboratory of Bio-Control, Moe Key Laboratory of Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
authors.forename: Peipei
authors.initials: P
authors.lastname: Li
authors.forename: Xianjie
authors.initials: X
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Xuan-Xian
authors.initials: XX
authors.lastname: Peng
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D015536:Down-Regulation; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005420:Flavoproteins / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology*; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics*; D011808:Quinone Reductases / Q000235:genetics*; D044149:Vibrio alginolyticus / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D005420:Flavoproteins; D024841:Fluoroquinolones; D009247:NADH, NADPH Oxidoreductases; C099916:Nqrf protein, Vibrio alginolyticus; D011808:Quinone Reductases; C077155:balofloxacin