Geographical Variation in Antibiotic-Resistant Escherichia coli Isolates from Stool, Cow-Dung and Drinking Water

Little information is available on relationships between the biophysical environment and antibiotic resistance. This study was conducted to investigate the antibiotic resistance pattern of Escherichia coli isolated from child stool samples, cow-dung and drinking water from the non-coastal (230 households) and coastal (187 households) regions of Odisha, India. Susceptibility testing of E. coli isolates (n = 696) to the following antibiotics: tetracycline, ampicillin/sulbactam, cefuroxime, cefotaxime, cefixime, cotrimoxazole, amikacin, ciprofloxacin, norfloxacin and nalidixic acid was performed by the disk diffusion method. Ciprofloxacin minimum inhibitory concentration (MIC) values were determined for ciprofloxacin-resistant isolates (n = 83). Resistance to at least one antibiotic was detected in 90% or more of the E. coli isolates. Ciprofloxacin MIC values ranged from 8 to 32 mu g/mL. The odds ratio (OR) of resistance in E. coli isolates from children's stool (OR = 3.1, 95% CI 1.18-8.01), cow-dung (OR = 3.6, 95% CI 1.59-8.03, P = 0.002) and drinking water (OR = 3.8, 95% CI 1.00-14.44, P = 0.049) were higher in non-coastal compared to coastal region. Similarly, the co-resistance in cow-dung (OR = 2.5, 95% CI 1.39-4.37, P = 0.002) and drinking water (OR = 3.2, 95% CI 1.36-7.41, P = 0.008) as well as the multi-resistance in cow-dung (OR = 2.2, 95% CI 1.12-4.34, P = 0.022) and drinking water (OR = 2.7, 95% CI 1.06-7.07, P = 0.036) were also higher in the non-coastal compared to the coastal region.