文献类型：期刊文献

英文题名：Systematic mutation analysis of two-component signal transduction systems reveals EsrA-EsrB and PhoP-PhoQ as the major virulence regulators in Edwardsiella tarda

作者：Lv, Yuanzhi[1];Xiao, Jingfan[1];Liu, Qin[1];Wu, Haizhen[1];Zhang, Yuanxing[1];Wang, Qiyao[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2012

卷号：157

期号：1-2

起止页码：190

外文期刊名：VETERINARY MICROBIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000303903500025)】；

基金：We thank Edward G. Ruby for critical reading of the manuscript. This work was supported by grants from the National High Technology Research and Development Program of China (2008AA092501), Ministry of Agriculture of China (CARS-50), the National Special Fund for State Key Laboratory of Bioreactor Engineering (No. 2060204) as well as Shanghai Leading Academic Discipline Project (No. B505).

语种：英文

外文关键词：Edwardsiella tarda; Two-component system; Virulence; EsrB; PhoP; Antimicrobial peptide

摘要：Edwardsiella tarda is a Gram-negative broad-host-range pathogen that causes hemorrhagic septicemia in many commercially important fish species. Its ability to adapt to and thrive in diverse environments outside and inside of its hosts prompts us to investigate the roles of the previously identified 33 putative two-component signal transduction systems (TCSs) in E. tarda. In this work, we successfully constructed deletion mutations in each of the response regulator genes, suggesting that none of the TCSs are essential for cell viability in E. tarda. The mutants were further examined for roles in biofilm formation, antibiotic resistance, stress response, expression and secretion of proteins involved in either the type III secretion system (T3SS) or type VI secretion system (T6SS), as well as virulence. Through these assays, we identified four regulators of biofilm development, two regulators of antibiotic resistance, and four regulators involved in stress responses. We found that two regulators, EsrB and PhoP, are essential for the pathogenicity of E. tarda and further demonstrated that these two regulators have codependent and independent contributions to E. tarda virulence. Mutation of EsrB resulted in the complete loss of both the T3SS and T6SS proteins, while PhoP partially regulated the expression of T3SS and T6SS genes through EsrB, and was essential for resistance to antimicrobial peptides. This work suggested that these two response regulators are involved in the regulation of the complex virulence network of this bacterium and merit as candidate genes for live attenuated vaccine construction. (C) 2011 Elsevier B.V. All rights reserved.