Nile tilapia vaccination using Aeromonas hydrophila ghost cells and its effects on genic expression of IFN-gamma and TNF-alpha

• Grant number: 24/20707-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Ricardo Luiz Moro de Sousa
• Grantee: Marcos Vinicius Dutra de Oliveira
• 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

Aquaculture has been the fastest-growing branch of agriculture over the past three decades, accounting for more than half of the world's animal protein production. With the expansion of aquaculture production, there has been an intensification of production processes, which has increased the frequency and severity of bacterial disease outbreaks, such as aeromoniasis, commonly attributed to Aeromonas hydrophila, a facultative intracellular Gram-negative bacillus. To mitigate mortality and consequent economic losses, as well as to avoid the use of antimicrobial agents, prophylactic methods have become necessary, with vaccination being particularly noteworthy. Fish vaccination is already a common practice on farms in countries where aquaculture is more established and has gained momentum in Brazil. Among the types of vaccines, inactivated vaccines stand out, where the pathogen is killed by chemical or physical agents, making the vaccine safe and without the risk of infection from the vaccination process itself. However, most inactivation methods reduce the antigenicity and immunogenicity of vaccine particles due to protein antigen degradation, requiring the use of adjuvants to ensure a better immune response. The "ghost cell" production technique allows for bacterial inactivation with minimal protein degradation and near-intact cell morphology preservation, resulting in more robust immune responses and reducing the need for adjuvants. Therefore, aiming to evaluate the recognition potential of Nile tilapia to A. hydrophila "ghost cells," this project aims to analyze the expression of interferon-gamma and TNF-alpha genes in fish injected or not with the vaccine.