Prevalence of antimicrobial resistant Aeromonas in chicken and fish washings

This study was undertaken to assess prevalence of virulent and antibiotic-resistant Aeromonas species in chicken meat and fresh water fish washings procured from local market. Isolation was done on three selective agar viz. Aeromonas isolation media, ampicillin dextrin agar and Aeromonas starch DNA agar. Presumptive colonies were directly screened by multiplex polymerase chain reaction (PCR) targeting genus specific 16S rRNA gene, aerolysin (aerA) of Aeromonas hydrophila and hemolysin (asa1) gene of Aeromonas sobria. Of the 200 samples (100 each of chicken and fish washings), 21 isolates were confirmed as Aeromonas species. We could not detect aer A, however, asa1 of A. sobria was detected in six (28.57%) fish isolates. Aeromonas isolates exhibited 100% resistant to amoxicillin, ampicillin and 95.23% to carbenicillin. Moderate sensitivity was observed to kanamycin (90.47%) and neomycin (71.42%). Isolates were 100% sensitive to gentamicin and ciprofloxacin. Maximum sensitivity was recorded with chloramphenicol, tobramycin (95.23% each) and amikacin (80.95%). PCR characterization revealed presence of class 1 integron and Tet (C) genes in six and 10 isolates, respectively. PSE-1 β-lactamase was not detected in any of the isolates. This study demonstrate the incidence of antimicrobial resistant Aeromonas in chicken and fish environment, which may be a potential source of spread of this enteropathogen in food chain. Key words: Aeromonads, antimicrobial resistance, chicken, fish.