Development of an oral vaccine based on recombinant Bacillus subtilis endospores for tilapia (Oreochromis niloticus) against infection spleen and kidney necrosis virus (ISKNV)

• Grant number: 24/10640-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: February 01, 2025
• End date: October 31, 2027
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Ricardo Luiz Moro de Sousa
• Grantee: Talita Maria Lazaro
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 21/11955-8 - Solutions for emerging diseases in fish farming: diagnosis, vaccines and breeding, AP.CCD

Abstract

Global aquaculture production is expanding and a significant increase in the production of tilapia (Oreochromis niloticus) can be observed in Brazil, being the species that leads the aquaculture ranking in the country. However, there are challenges that need to be overcome, such as the emergence of pathogens that were previously unidentified in Brazil, such as the infection spleen and kidney necrosis virus (ISKNV), recently reported in the country. Vaccination presents itself as an extremely interesting strategy that aims to avoid greater economic losses resulting from diseases in the herd. Therefore, the development of new generation vaccines, such as recombinant vaccines based on immunogenic proteins added with adjuvants, and which can be administered orally, are seen as promising alternatives, capable of providing protection against specific agents through vaccine protocols easy to manage and minimized stress to the animals. In this context, the present project aims to develop and evaluate the immunogenicity of a vaccine based on the Bacillus subtilis prokaryotic vector expressing a recombinant heterologous protein obtained from the fusion between the MCP (Major Capsid Protein) protein of a Brazilian strain of ISKNV, the main immunogenic protein of this viral agent, and CTB, non-toxic subunit B of cholera toxin, normally used as an adjuvant. The vaccine is expected to be able to increase the expression of cytokines and stimulate the production of anti-ISKNV antibodies in vaccinated tilapia.