CONSTRUCTION AND PROTECTION EVALUATION OF A BIVALENT DNA VACCINE CONTAINING tdh2 OF VIBRIO PARAHAEMOLYTICUS AND ompU OF V.ANGUILLARUM ON TURBOT SCOPHTHALMUS MAXIMUS
2011; Linguagem: Inglês
ISSN
0029-814X
Autores Tópico(s)Invertebrate Immune Response Mechanisms
ResumoVibriosis is one of the most prevalent fish diseases caused by bacteria that belong to the genus Vibrio, in which Vibrio parahaemolyticus and V. anguillarum are two most common pathogenic agents. In this study, a thermostable direct hemolysin (TDH) gene tdh2 of V. parahaemolyticus and an outer membrane protein (OMP) gene ompU of V. anguil-larum were inserted into prokaryotic expression vector pET28a (+) successively. Then the gene encoding the fusion protein TDH2-OmpU was used to construct bivalent DNA vaccine. The protective efficiency of such vaccine against V. para- haemolyticus and V. anguillarum was evaluated in turbot Scophthalmus maximus. Fish immunized with a single intramus-cular injection of different doses of the tdh2-ompU DNA vaccine showed significantly higher serum antibody levels after vaccination, compared to fish injected with the control eukaryotic expression vector pEGFP-N1. Four weeks after inoculation, turbot vaccinated with the bivalent DNA vaccine were exposed to V. parahaemolyticus and V. anguillarum by intraperitoneal injection and intramuscular injection, respectively. The highest relative percent survival (RPS) rates, 100% against V. parahaemolyticus and 35% against V. anguillarum, respectively, were recorded. Furthermore, humoral immune responses and protective effects significantly increased at higher vaccine doses.
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