The mobile gene cassette carrying tetracycline resistance genes in strain Ah5S-24 isolated from catfish pond sediments shows similarity with a cassette found in other environmental and foodborne bacteria.

is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen that causes diarrhea in humans and hemorrhagic septicemia in fish. In the present study, we used whole-genome sequencing (WGS) to evaluate the presence of antimicrobial resistance (AMR) and virulence genes found in Ah5S-24 isolated from catfish pond sediments in South-East, United States. We found , , , , , and resistance genes encoded in the chromosome of Ah5S-24. We also found the tetracycline and genes placed next to the ISIS transposase, integrase, and hypothetical proteins that formed as a genetic structure or transposon designated as ISIS. BLAST analysis showed that a similar mobile gene cassette (MGC) existed in chromosomes of other bacteria species such as isolated from retail fish at markets, from human stool and from a sewage bioreactor. In addition, the ISIS cassette was also found in the plasmid of isolated from shrimp. As for virulence genes, we found the tap type IV pili ( and ), polar flagellae ( and ), lateral flagellae ( and ), and fimbriae ( and ) genes responsible for motility and adherence. We also found the hemolysin genes (, and ), toxin, biofilm formation, and quorum sensing (, and ) genes. However, there were no MGCs encoding virulence genes found in AhS5-24. Thus, our findings show that MGCs could play a vital role in the spread of AMR genes between chromosomes and plasmids among bacteria in aquatic environments. Overall, our findings are suggesting that MGCs encoding AMR genes could play a vital role in the spread of resistance acquired from high usage of antimicrobials in aquaculture to animals and humans.