文献类型：期刊文献

英文题名：Comparative analysis of the roles of catalases KatB and KatG in the physiological fitness and pathogenesis of fish pathogen Edwardsiella tarda

作者：Xiao, J.[1];Chen, T.[1];Wang, Q.[1];Zhang, Y.[1]

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

年份：2012

卷号：54

期号：5

起止页码：425

外文期刊名：LETTERS IN APPLIED MICROBIOLOGY

收录：;EI(收录号：20231113722728);WOS:【SCI-EXPANDED(收录号:WOS:000302615600008)】；

基金：This work was supported by grants from the Ministry of Agriculture of China (no. CARS-50), the National High Technology Research and Development Program of China (no. 2008AA092501) and the National Special Fund for State Key Laboratory of Bioreactor Engineering (no. 2060204).

语种：英文

外文关键词：catalase; Edwardsiella tarda; katB; katG; virulence

摘要：Aims: The aim of this study was to reveal functional redundancy and variation of the two catalases KatB and KatG in Edwardsiella tarda. Methods and Results: Genome sequencing of fish pathogen Edw. tarda EIB202 reveals that it contains two genes putatively encoding catalases, katB (ETAE_1368) and katG (ETAE_0889). Under free-living conditions, single disruption in katB or katG resulted in no growth impairment, whereas double mutation of the two genes led to moderate decrease in growth, indicating that these two catalases were together essential for the physiological fitness by dissipating the endogenous H2O2. katG mutant exhibited much more elevated sensitivity to exogenous H2O2 than katB mutant did, indicating that KatG was quasi-essential in detoxifying external reactive oxygen species (ROS) in Edw. tarda EIB202. Further comparative analysis indicated that katB or katG disruption showed different effects on the virulence-related processes of Edw. tarda such as haemolysin production, bile and serum resistance, as well as the internalization within fish epithelial cells. Moreover, both of the katB and katG mutants exhibited incapacity to replicate in murine macrophage J774 cell model, although the deficiency was seen much severe for Delta katB/katG mutant. With regard to in vivo virulence, katB and katG mutants displayed delayed lethality and increased LD50 values for zebrafish. Conclusions: KatB and KatG in Edw. tarda serve for the physiological fitness, and pathogenesis related the bacterial survival in macrophage and in vivo of fish. Significance and Impact of the Study: Counteracting ROS for systemic infection, Edw. tarda catalase KatG and KatB merits as potential targets for attenuated live vaccine construction.