Antibiotic susceptibility and resistance of Aeromonas spp. isolated from fish

Abstract

The sensitivity of 24 isolates of Aeromonas spp. isolated from the muscle of different species of fish was
compared using commonly used antibiotics. The in vitro susceptibility of the isolates was studied by disk
diffusion method using discs (Oxoid) containing the following antibiotics were used: penicillin
G (10 U), tetracycline (30 μg), gentamycin (30 μg), azitromycin (15 μg), trimethoprim-sulfamethoxazole (25
μg), naladixic acid (30 μg) and norfloxacin (10 μg). All bacterial strains studied in this research showed
high degree of resistance to antibiotics. According to the results, 91.6% of studied isolates were resistant
to antibiotics. Resistance rate to tetracycline and penicillin was more than other antibiotics. Multiple drug
resistance was also observed in all Aeromonas hydrophila isolates.