Prevalence, Antimicrobial Susceptibility and Resistance Gene Detection in Bacteria Isolated from Goldfish and Tiger Barb from Ornamental Fish Farms of Tamil Nadu.

This study aims to determine the antimicrobial resistance (AMR) pattern in freshwater ornamental cyprinids, such as Goldfish and Tiger barb. Molecular characterization of bacterial isolates confirmed the presence of 7 bacterial isolates in Goldfish and 6 in Tiger barb. Antimicrobial susceptibility test using 36 antibiotics revealed a higher resistance pattern for bacitracin, rifampicin, trimethoprim, cefalexin, ampicillin, amoxicillin, nalidixic acid and nitrofurantoin. Sulphafurazole, norfloxacin and ciprofloxacin were effective against all the bacterial isolates derived from Goldfish and Tiger barb. Most bacterial isolates exhibited > 0.2 multi-drug resistance index (MDR), indicating the severity of antibiotic use in the culture system. The finding of the present study suggests that ornamental fish may act as the reservoir of MDR bacteria and dissemination of resistance genes to clinical and human commensal bacteria through horizontal gene transfer. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01023-y. © Association of Microbiologists of India 2022.