| সংক্ষিপ্ত: | The aims of this study were to characterize and investigate antimicrobial susceptibility and presence of integrons in 161 <i>Aeromonas</i> spp. isolated from ornamental freshwater fish farming environment, apparently healthy and diseased fish. Phylogenetic analyses of the <i>gyrB</i> gene sequences identified <i>Aeromonas veronii</i> as the most abundant species (75.8%) followed by <i>Aeromonas</i><i>hydrophila</i> (9.3%), <i>Aeromonas caviae</i> (5%), <i>Aeromonas jandaei</i> (4.3%), <i>Aeromonas dhakensis</i> (3.7%), <i>Aeromonas sobria</i> (0.6%), <i>Aeromonas media</i> (0.6%), and <i>Aeromonas popoffii</i> (0.6%). Susceptibility to thirteen antimicrobials was determined and antimicrobial resistance frequencies were: amoxicillin (92.5%), enrofloxacin (67.1%), nalidixic acid (63.4%), erythromycin (26.1%), tetracycline (23.6%), imipenem (18%), trimethoprim-sulfamethoxazole (16.8%), and gentamicin (16.8%). Multi-drug resistance (MDR) was widespread among the isolates (51.6%, 83/161) with 51.6% (63/122) <i>A. veronii</i> isolates being MDR. In addition, 68.3% of isolates had multiple antibiotic resistance (MAR) indexes higher than 0.2, suggesting that they originated from a high-risk source of contamination where antimicrobials are often used. In all, 21.7% isolates carried class 1 integrons, with 97.1% having gene cassettes, while there were 12 isolates carrying class 2 integron gene cassettes. Our findings highlight that the aquatic environment and ornamental fish act as reservoirs of multidrug resistant <i>Aeromonas</i> spp. and underline the need for a judicious use of antimicrobials and timely surveillance of antimicrobial resistance (AMR) in aquaculture.
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