State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, Faculty of Food Science and Engineering, Beijing University of Agriculture, Beijing, 102206, China.
FEMS Microbiol Lett. 2018 Jul 1;365(14). doi: 10.1093/femsle/fny137.
Edwardsiella piscicida is an infectious Gram-negative bacterium that causes great losses to the aquaculture industry worldwide. Based on pattern analysis of conditional essentiality (PACE), a new method for transposon insertion sequencing (Tn-seq) data analysis, we investigated the genome-wide genetic requirements during the dynamic process of infection and colonization in turbot in this study. As a result, disruption of ETAE_1437 was discovered to lead to substantially reduced colonization, which was similar to the in vivo dynamic patterns of the mutants of T3SS or T6SS. Bioinformatics analysis indicated that ETAE_1437 is a YebC/PmpR family regulator. Moreover, we found that ETAE_1437 not only regulated quorum sensing by directly binding to the edwR promoter region but also activated T3SS expression by directly binding to the promoter region of the T3SS gene ETAE_0873. In addition, ETAE_1437 mutants exhibited substantial colonization defects and significantly decreased virulence in turbot. Overall, this study identified ETAE_1437 as a novel virulence regulator in E. piscicida and enriched our understanding of the pathogenesis of E. piscicida in fish. We thus reannotated ETAE_1437 as YebC.
爱德华氏菌是一种传染性革兰氏阴性菌，它给全球水产养殖业造成了巨大损失。基于条件必需性模式分析（PACE），一种新的转座子插入测序（Tn-seq）数据分析方法，我们在这项研究中研究了大菱鲆感染和定植过程中的全基因组遗传需求。结果发现，ETAE_1437 的缺失导致定植能力显著降低，这与 T3SS 或 T6SS 突变体的体内动态模式相似。生物信息学分析表明，ETAE_1437 是 YebC/PmpR 家族调控因子。此外，我们发现 ETAE_1437 不仅通过直接结合 edwR 启动子区域来调节群体感应，还通过直接结合 T3SS 基因 ETAE_0873 的启动子区域来激活 T3SS 的表达。此外，ETAE_1437 突变体在大菱鲆中的定植缺陷和毒力显著降低。总之，这项研究鉴定了 ETAE_1437 是爱德华氏菌中的一种新型毒力调控因子，丰富了我们对鱼类爱德华氏菌发病机制的认识。因此，我们将 ETAE_1437 重新注释为 YebC。
