Antimicrobial resistance and associated genetic determinants of Aliivibrio colonizing the gastrointestinal tract of farmed Atlantic Salmon (Salmo salar L.)

Susceptibility was observed for chloramphenicol, oxolinic acid, ciprof-loxacin, rifampicin, meropenem, trimethoprim, and trimethoprim-sulfamethoxazole. The resistance profile of Aliivibrio isolates can be explained by intrinsic resistance coinciding with a core set of ARGs common for genus Aliivibrio. Plasmids or integrons carrying ARGs were not found amongst the salmon isolates.

Strains of several Aliivibrio species carried ARGs on integrons based on available genome data, including genes providing potential resistance to chloramphenicol (cpt, catB), tetracyclines (tetE), sulfonamides (sul2), trime-thoprim (dfrA1), and potentially aminoglycosides. From the results resistance levels be-yond estimated epidemiological cutoff values has likely not occurred in Aliivibrio in At-lantic salmon farmed in Tasmania.

Predominance of the strains in the Atlantic salmon gut microbiome could be at least partly enabled by intrinsic resistance to antibiotics. The data represented here includes the following: 1) Antibiotic resistance array data showing presence absence for individual ARGs for Aliivibrio genomes. 2) Integron locational data for Aliivibrio genomes. 3) MIC data 4) 16S rRNA gene sequences (V1-V3 region) only. Data published in prior paper (frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2025.1564052/full) 5) Supplementary data a) Genome data for Aliivibrio including results of Mob-Recon (plasmids) b) List of ARG genes found in Aliivibrio c) Integron results summary including protein coding gene content and ARG presence d) Phylogram showing alignment of CatB (chloramphenicol acetytransferase type B) and Vat (virginiamycin/streptogramin acetytransferase) proteins from Aliivibrio compared to reference proteins from KEGG orthology.