Back to Search
Start Over
Edwardsiella tarda T6SS component evpP is regulated by esrB and iron, and plays essential roles in the invasion of fish.
- Source :
-
Fish & shellfish immunology [Fish Shellfish Immunol] 2009 Sep; Vol. 27 (3), pp. 469-77. Date of Electronic Publication: 2009 Jun 27. - Publication Year :
- 2009
-
Abstract
- Edwardsiella tarda is a gram-negative pathogen for hemorrhagic septicemia in a broad range of hosts. The type VI secretion system (T6SS) has recently been dissected in E. tarda to secrete EvpC, EvpI and a novel effector protein EvpP. In this study, sequencing and genetic alignments showed that evpP genes from different E. tarda isolates were highly similar and an evpP homolog was also found in Aeromonas hydrophila 0865 isolated from a diseased eel, suggesting the possible lateral gene transfer of evpP or the whole T6SS gene island. With reporter strains carrying gfp gene fused to the evpP promoter region, flow cytometric analysis revealed that transcription of evpP was positively regulated by either the two-component system EsrA-EsrB in E. tarda or the iron concentration in media. Compared with the parental strain, in-frame deletion of evpP in E. tarda EIB202 led to the significantly increased 50% lethal doses in zebrafish (Danio rerio) and Japanese flounder (Paralichthys olivaceus), decreased hemolytic activities, failure to adhere to mucus and reduced serum resistance, and complementation of an intact evpP gene restored these phenotypes in the evpP mutant. Investigation of infection kinetics indicated that the evpP deletion mutant was unable to proliferate in vivo, particularly in immune organs of fish. Moreover, the evpP deletion mutant exhibited incapacity to internalize in EPC cell model in vitro, demonstrating that EvpP in T6SS plays critical roles for invasion mechanism of E. tarda and merits as potential target for attenuated live vaccine construction.<br /> (2009 Elsevier Ltd.)
- Subjects :
- Animals
Bacterial Proteins chemistry
Cell Line, Tumor
Edwardsiella tarda genetics
Enterobacteriaceae Infections microbiology
Enterobacteriaceae Infections mortality
Fish Diseases mortality
Flatfishes microbiology
Hemolysis
Mucus metabolism
Sequence Deletion
Virulence genetics
Zebrafish microbiology
Bacterial Proteins metabolism
Edwardsiella tarda metabolism
Edwardsiella tarda pathogenicity
Enterobacteriaceae Infections veterinary
Fish Diseases microbiology
Iron metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1095-9947
- Volume :
- 27
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Fish & shellfish immunology
- Publication Type :
- Academic Journal
- Accession number :
- 19563898
- Full Text :
- https://doi.org/10.1016/j.fsi.2009.06.013