Antibiotic-Resistant Escherichia coli Isolated from Duck Cloacal and Tap Water Samples at Live Bird Markets in Bangladesh

Antibiotic resistance is a growing concern all over the world. The current study sought to identify antimicrobial resistance (AMR) patterns and antibiotic-resistant genes in Escherichia coli (E. coli) isolated from seemingly healthy ducks and neighboring tap water sources at three separate live bird markets (LBMs) in Chattogram, Bangladesh. A total of ninety cloacal swab samples of Khaki Campbell ducks and fifteen water samples from nearby tap water sources were collected from three LBMs. Several cultural and molecular tests were conducted to determine  E. coli contamination. The disk diffusion technique was used to evaluate the antibiotic sensitivity of E. coli isolates to 12 different antibiotics. For each isolate, a Multiple Antibiotic Resistance (MAR) index was calculated. The resistance genes were detected using a polymerase chain reaction (PCR) assay. The overall prevalence of E. coli in feces and tap water samples was 64.4% (58/90, 95% CI 54.1-73.6) and 100% (15/15, 95% CI 76.1-100), respectively. Both fecal and water isolates showed 100% resistance to ampicillin, tetracycline, and nalidixic acid. Resistance to other antibiotics was also found to be high. Multidrug- resistance (MDR) was unveiled in all fecal (58/58) and water (15/15) isolates. MAR index ranged from 0.33 to 0.67 in all recovered isolates. Both fecal and water E. coli isolates harbored blaTEM, tetA, sul1, and sul2 genes. The resistance genes in MDR E. coli in live bird markets might transmit from ducks to humans and they, therefore local authorities should consider this issue a major public health risk.