The Tryptophan Biosynthesis Gene trpE Contributes to Virulence in Mesophilic Aeromonas salmonicida SRW-OG1

Abstract

Simple Summary Aeromonas salmonicida causes severe mortality in grouper and other farmed fish, resulting in considerable economic losses in aquaculture. Although the trpE gene participates in tryptophan biosynthesis, its role in bacterial virulence remains unclear. Here, we investigated the function of trpE in A. salmonicida SRW-OG1. Deletion of trpE impaired bacterial growth, flagella formation and multiple virulence traits. In vivo assays confirmed that mutant exhibite attenuated virulence, and reduced tissue colonization, offering effective immune protection against wild-type infection. Omics analyses revealed that trpE modulates bacterial pathogenicity via quorum sensing and motility pathways, supporting its potential as a live attenuated vaccine candidate.