Roles of three TonB systems in the iron utilization and virulence of the Aeromonas hydrophila Chinese epidemic strain NJ-35

文献类型： 外文期刊

第一作者： Dong, Yuhao

作者： Dong, Yuhao;Geng, Jinzhu;Liu, Jin;Awan, Furqan;Lu, Chengping;Liu, Yongjie;Pang, Maoda

作者机构：

关键词： Aeromonas hydrophila; TonB systems; Iron acquisition; Virulence; Environmental survival

期刊名称：APPLIED MICROBIOLOGY AND BIOTECHNOLOGY （ 影响因子：4.813； 五年影响因子：4.697 ）

ISSN： 0175-7598

年卷期： 2019 年 103 卷 10 期

页码：

收录情况： SCI

摘要： The TonB system functions in iron transport and has been identified in certain Gram-negative bacteria. Recently, we reported three TonB systems in the Aeromonas hydrophila Chinese epidemic strain NJ-35, but the functions of these systems have not been thoroughly elucidated to date. In this study, we investigated the role of these TonB systems in A. hydrophila iron utilization and virulence. We found that tonB1 and tonB2 were preferentially transcribed in iron-chelated conditions, where gene expression levels were approximately 8- and 68-fold higher compared with iron-rich conditions, respectively; tonB3 was consistently transcribed at a low level under iron-repleted and iron-depleted conditions. Only the TonB2 system was required to utilize iron-binding proteins. The tonB123 mutant showed increased susceptibility to erythromycin and roxithromycin. In addition, all three tonB genes were involved in A. hydrophila virulence in zebrafish, and various phenotypes associated with environmental survival were changed with varying degrees in each tonB mutant. TonB2 plays a relatively major role in adhesion, motility, and biofilm formation, while TonB3 is more involved in the anti-phagocytosis of A. hydrophila. In each observed phenotype, no significant difference was found between the single- and double-deletion mutants, whereas the triple-deletion mutant exhibited the most serious defects, indicating that all three TonB systems of A. hydrophila coordinately complement one another. In conclusion, this study elucidates the importance of TonB in iron acquisition and virulence of A. hydrophila, which lays the foundation for future studies regarding the survival mechanisms of this bacterium in iron-restricted environments.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序