In silico Evaluation of Outer Membrane Protein S2 as a Suitable Vaccine Candidate Against Edwardsiella tarda Infection of Fish

Abstract Edwardsiella tarda is one of the primary emerging pathogens in fish aquaculture, responsible for Edwardsiellosis. The disease leads to significant economic loss to the farmers. Development of effective vaccines can minimise the disease burden. The type of vaccinations that are currently at the center of the most significant research are subunit vaccines. Outer membrane proteins (OMPs), being a component of the bacteria are very well known to be effective at stimulating immune responses in the host. In this study, the gene encoding for outer membrane protein S2 (OmpS2) of E. tarda was identified, cloned, and sequenced, followed by in silico analysis. The structure and sub‐cellular localization of the protein was first confirmed. Homology modelling of the whole protein was done and checked for its eligibility as a vaccine candidate. This was followed by identifying antigenic sites, B cell epitopes, and cytotoxic T‐lymphocyte epitopes on OmpS2. We obtained a few distinct vaccine peptides from the OmpS2. The complete genome of the fish pathogen E. tarda was subjected to genome analysis to identify potential epitopes that would bind to the fish major histocompatibility complex (MHC) molecule to elicit both humoral and cell‐mediated immune responses. This study provides valuable insights to consider OmpS2 as a potential vaccine candidate against E. tarda infection .