Reverse vaccinology for development of vaccine against Aeromonas hydrophila infection in nile tilapia (Oreochromis niloticus)

Abstract

Aeromonas hydrophila is one of the main pathogens of Tilapia and has a wide range phenotype, making it difficult to prevent by a unique vaccine. And turning the majority of the treatment using antibiotics. The aim of this work was to predict vaccine candidate with potential efficacy to protect Oreochromis niloticus against Aeromonas hydrophila, applying bioinformatics tools in a reverse vaccinology approach. It was obtained 35 A. hydrophila genomes in the São Francisco Valley in Petrolina/PE/Brazil, as well as 24 A. hydrophila and 02 O. niloticus complete genomes available in Genbank. After identification of core genes of Aeromonas hydrophila and a subtractive genomics analysis between the O. niloticus genome and A. hydrophila genome, 32 of the 178 resulting proteins, were considered likely vaccine targets as they showed a high adherence probability (> 0.51) in the Vaxign tool. After BLAST analysis against the database of essential genes (DEG), 18 proteins showed defined criteria e-value (≤ 10− 6) and a relevant similarity with the proteins of pathogenic species from the genus Aeromonas. Were selected 10 proteins, based on the criteria of portability adhesion, molecular mass between 19 and 80 kDa and presence of one or no transmembrane helix. The analyses identified nine proteins [secreted (n = 8) and PSE (n = 1)] with immunological and novel properties as candidates for vaccine targets. Finally, in vitro/in vivo tests will be necessary to experimentally validate the results of this search.