title: Eha, a regulator of Edwardsiella tarda, required for resistance to oxidative stress in macrophages.
abstract: Edwardsiella tarda is distributed widely in a variety of hosts. Eha has recently been found to be its virulence regulator. In order to explore the mechanism of its regulation, we investigated the survival rates of wild type strain ET13, and its eha mutant and complemented strains in RAW264.7 macrophages under light microscopic observation as well as by counting bacterial CFUs on the plates. All of the different strains could live within the macrophages; however, the intracellular numbers of the wild type were significantly higher than the mutant when the incubation time extended 4 h or 6 h (P < 0.05). Furthermore, more ROS were produced by the mutant-infected cells, indicating that Eha may enhance ET13's capacity to detoxify ROS. In agreement with this, we found that the mutant exhibited more sensitivity by H2O2disk inhibitory assay and less survival ability with H2O2treatment. We further demonstrated that the bacterial antioxidant enzymes SodC and KatG were regulated by Eha with qRT-PCR and β-galactosidase assay. Collectively, our data show Eha is required for E. tarda to resist the oxidative stress from the macrophages.
authors: Department of Pathogenic Microbiology and Immunology, Southeast University School of Medicine, Nanjing, China dgao2@seu.edu.cn.
authors: Daqing
authors: D
authors: Gao
authors: Department of Pathogenic Microbiology and Immunology, Southeast University School of Medicine, Nanjing, China.
authors: Yuhong
authors: Y
authors: Li
authors: Department of Pathogenic Microbiology and Immunology, Southeast University School of Medicine, Nanjing, China.
authors: Enjin
authors: E
authors: Zheng
authors: Department of Pathogenic Microbiology and Immunology, Southeast University School of Medicine, Nanjing, China.
authors: Nian
authors: N
authors: Liu
authors: Department of Clinical Lab, Southeast University School of Medicine, Nanjing, China.
authors: Zeye
authors: Z
authors: Shao
authors: NanJing Agricultural University, College of Veterinary Medicine, Nanjing, China.
authors: Chengping
authors: C
authors: Lu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D002374:Catalase / Q000235:genetics; D002460:Cell Line; D020609:Edwardsiella tarda / Q000235:genetics* / Q000472:pathogenicity*; D006460:Hemolysin Proteins / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D014157:Transcription Factors; D037521:Virulence Factors; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Edwardsiella tarda; eha gene; ROS; regulator