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Edwardsiella tarda sialidase: pathogenicity involvement and vaccine potential.
- Source :
-
Fish & shellfish immunology [Fish Shellfish Immunol] 2012 Sep; Vol. 33 (3), pp. 514-21. Date of Electronic Publication: 2012 Jun 13. - Publication Year :
- 2012
-
Abstract
- Bacterial sialidases are a group of glycohydrolases that are known to play an important role in invasion of host cells and tissues. In this study, we examined in a model of Japanese flounder (Paralichthys olivaceus) the potential function of NanA, a sialidase from the fish pathogen Edwardsiella tarda. NanA is composed of 670 residues and shares low sequence identities with known bacterial sialidases. In silico analysis indicated that NanA possesses a sialidase domain and an autotransporter domain, the former containing five Asp-boxes, a RIP motif, and the conserved catalytic site of bacterial sialidases. Purified recombinant NanA (rNanA) corresponding to the sialidase domain exhibited glycohydrolase activity against sialic acid substrate in a manner that is pH and temperature dependent. Immunofluorescence microscopy showed binding of anti-rNanA antibodies to E. tarda, suggesting that NanA was localized on cell surface. Mutation of nanA caused drastic attenuation in the ability of E. tarda to disseminate into and colonize fish tissues and to induce mortality in infected fish. Likewise, cellular study showed that the nanA mutant was significantly impaired in the infectivity against cultured flounder cells. Immunoprotective analysis showed that rNanA in the form of a subunit vaccine conferred effective protection upon flounder against lethal E. tarda challenge. rNanA vaccination induced the production of specific serum antibodies, which enhanced complement-mediated bactericidal activity and reduced infection of E. tarda into flounder cells. Together these results indicate that NanA plays an important role in the pathogenesis of E. tarda and may be exploited for the control of E. tarda infection in aquaculture.<br /> (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Subjects :
- Animals
Cell Culture Techniques veterinary
Edwardsiella tarda immunology
Edwardsiella tarda metabolism
Edwardsiella tarda pathogenicity
Enterobacteriaceae Infections immunology
Enterobacteriaceae Infections prevention & control
Enterobacteriaceae Infections veterinary
Enzyme-Linked Immunosorbent Assay veterinary
Fish Diseases immunology
Fish Proteins genetics
Injections, Intraperitoneal veterinary
Microscopy, Fluorescence veterinary
Molecular Sequence Data
Oxo-Acid-Lyases genetics
Phylogeny
Recombinant Proteins immunology
Sequence Alignment veterinary
Sequence Analysis, Protein veterinary
Vaccines, Subunit immunology
Vaccines, Synthetic immunology
Virulence
Bacterial Vaccines immunology
Edwardsiella tarda genetics
Fish Diseases prevention & control
Fish Proteins metabolism
Flounder
Oxo-Acid-Lyases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1095-9947
- Volume :
- 33
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Fish & shellfish immunology
- Publication Type :
- Academic Journal
- Accession number :
- 22705341
- Full Text :
- https://doi.org/10.1016/j.fsi.2012.06.002