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The serine protease autotransporter Tsh contributes to the virulence of Edwardsiella tarda.
- Source :
-
Veterinary microbiology [Vet Microbiol] 2016 Jun 30; Vol. 189, pp. 68-74. Date of Electronic Publication: 2016 Apr 25. - Publication Year :
- 2016
-
Abstract
- The temperature-sensitive hemagglutinin (Tsh), identified as serine protease autotransporters of the Enterobacteriaceae (SPATEs) proteins, is an important virulence factor for avian-pathogenic Escherichia coli (APEC) and uropathogenic E. coli. However, little is known about the role of Tsh as a virulence factor in Edwardsiella tarda, a severe fish pathogen. In this study, we characterized the Tsh of E. tarda (named TshEt) and examined its function and vaccine potential. TshEt is composed of 1224 residues and has three functional domains typical for autotransporters. Quantitative real-time reverse transcriptase-PCR analysis showed that expression of tshEt was upregulated under conditions of high temperature, increased cell density, high pH, and iron starvation and during the infection of host cells. A markerless tsh in-frame mutant strain, TX01Δtsh, was constructed to determine whether TshEt participates in the pathogenicity of E. tarda, Compared to the wild type TX01, TX01Δtsh exhibited (i) retarded biofilm growth, (ii) decreased resistance against serum killing, (iii) impaired ability to block the host immune response, (iv) attenuated tissue and cellular infectivity. Introduction of a trans-expressed tsh gene restored the lost virulence of TX01Δtsh. The passenger domain of TshEt contains a putative serine protease (PepS) that exhibits apparent proteolytic activity when expressed in and purified from E. coli as a recombinant protein (rPepS). When used as a subunit vaccine to immunize Japanese flounder, rPepS was able to induce effective immune protection. This is the first study of Tsh in a fish pathogen, and the results suggest that TshEt exerts pleiotropic effects on the pathogenesis of E. tarda.<br /> (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Subjects :
- Animals
Bacterial Vaccines immunology
Edwardsiella tarda genetics
Edwardsiella tarda immunology
Escherichia coli genetics
Flounder immunology
Flounder microbiology
Gene Expression Regulation, Bacterial
Host-Pathogen Interactions
Recombinant Proteins genetics
Recombinant Proteins immunology
Serine Proteases genetics
Type V Secretion Systems immunology
Virulence immunology
Virulence Factors genetics
Edwardsiella tarda enzymology
Edwardsiella tarda pathogenicity
Serine Proteases immunology
Type V Secretion Systems genetics
Virulence genetics
Virulence Factors immunology
Subjects
Details
- Language :
- English
- ISSN :
- 1873-2542
- Volume :
- 189
- Database :
- MEDLINE
- Journal :
- Veterinary microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 27259829
- Full Text :
- https://doi.org/10.1016/j.vetmic.2016.04.021