Insights into mesophilic virulence, antibiotic resistant and human pathogenicity: A genomics study on the Aeromonas salmonicida SRW-OG1 newly isolated from the Asian fish Epinephelus coioides

In our previous study, a strain of Aeromonas salmonicida was isolated from diseased Epinephelus coioides with typical symptoms of furunculosis, and named as SRW-OG1. This is not only the first pathogenic A. salmonicida isolated from E. coioides, but also a putative mesophilic strain might be pathogenic to human. In the present study, the genome of SRW-OG1 was sequenced and compared with two mesophilic A. salmonicida strains isolated from human patients (C947 and AJ83). Their genomes were similar at the nucleotide level, and they shared most of the pathogen-host interaction factors, which further revealed the potential pathogenicity of SRW-OG1 to human. Besides, 17 CRISPRS, 6 gene islands, 6 antibiotic resistance genes and 12 prophages were identified in SRW-OG1 genome. The presence of prophage sequences may allow some bacteria to acquire antibiotic resistance, enhance their adaptability to the environment, improve their adhesion or make them pathogenic bacteria, which might explain the specific mechanisms that allow such mesophilic growth ability. •SRW-OG1 is the first pathogenic A. salmonicida isolated from E. coioides.•SRW-OG1 is a putative mesophilic strain might be pathogenic to human.•Genome analysis reveals the potential pathogenicity of SRW-OG1 to human.•Genome analysis explains the drug resistance of SRW-OG1.