Enteric Pathogenic and Multiple Antibiotic-Resistant Escherichia coli in Farmed Indian Major Carps and Their Environments in Peri-Urban Kolkata, India

Escherichia coli is targeted as a model bacterium for monitoring antimicrobial resistance (AMR). In this study, 232 E. coli strains from carp aquaculture environments were screened for AMR against 12 antibiotics. Maximum resistance was found against cefalexin, amoxyclav, azithromycin, nitrofurantoin, gentamycin, and oxytetracycline. Multiple antibiotic-resistance was noted in 98.70% of the strains with 49 resistant profiles. Twenty-four strains were serotyped into 12 O-groups (n = 21), rough type (n = 1), and untypeable (n = 2). Uropathogenic, enteropathogenic, enterotoxigenic, and enterohemorrhagic E. coli pathotypes were detected. The contamination of aquacultured carps with enteric pathogenic and MAR fecal bacteria from high-risk sources is a cause for concern.