title: A Streptococcus iniae DNA vaccine delivered by a live attenuated Edwardsiella tarda via natural infection induces cross-genus protection.
abstract: Edwardsiella tarda and Streptococcus iniae are important fish pathogens. We have reported previously a live E. tarda vaccine based on the attenuated strain TX5RM and a S. iniae DNA vaccine based on the antigen Sia10. In this study, we examined the possibility of constructing a cross-genus vaccine by taking advantage of the residual infectivity of TX5RM and using it as a carrier host for the natural delivery of a S. iniae DNA vaccine. For this purpose, the recombinant TX5RM, TX5RMS10, was created, which harbours and retains stably the DNA vaccine plasmid pCS10 that expresses Sia10. When flounder were vaccinated with TX5RMS10 via oral and immersion routes, TX5RMS10 was detected in multiple tissues within 12-14days postvaccination (p.v.). At 7 and 14 days p.v., expression of the DNA vaccine was detected in spleen, kidney and liver. Following E. tarda and S. iniae challenge at one and 2months p.v., the vaccinated fish exhibited relative per cent survival rates of 69-83%. Immunological analysis indicated that TX5RMS10-vaccinated fish produced specific serum antibodies and exhibited enhanced expression of a wide range of immune genes.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China Graduate University of the Chinese Academy of Sciences, Beijing, China Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China Graduate University of the Chinese Academy of Sciences, Beijing, China Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Hu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China Graduate University of the Chinese Academy of Sciences, Beijing, China Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.
authors.forename: C-S
authors.initials: CS
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China Graduate University of the Chinese Academy of Sciences, Beijing, China Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.
authors.forename: L
authors.initials: L
authors.lastname: Sun
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology; D056738:Cross Protection / Q000276:immunology; D020609:Edwardsiella tarda / Q000235:genetics / Q000276:immunology*; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D005432:Flounder / Q000276:immunology / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics; D013291:Streptococcus / Q000235:genetics / Q000276:immunology*; D014611:Vaccination / Q000379:methods; D014613:Vaccines, Attenuated / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA