Incidence of Antibiotic Resistant E. coli Isolated from Drinking Water Sources in Ondo, Southwestern Nigeria

Aim: The aim of this study was to determine the incidence and antibiotic resistant Escherichia coli in drinking water sources in Ondo, southwestern Nigeria.

Place and Duration of Study: Department of Biological Sciences, Wesley University of Science and Technology, Ondo between March and May, 2015.

Methodology: Fifty two (52) water samples were collected from streams and wells within and around Ondo town. Total aerobic mesophilic and coliform bacteria were determined by standard pour plate and multiple tube fermentation techniques respectively. Escherichia coli was isolated by cultivating on Eosin methylene blue (EMB) agar and tested for resistance to eight antibiotics by Kirby Bauer disc diffusion method.

Results: Total mesophilic count in the well and stream water samples were between 0.01 x 105 - 8.76 x 105cfu/ml and 1.31 x 105 - 4.20 x 105 cfu/ml respectively. The MPN/100 ml of the water: well (0.40 - >160) and streams (0.70 - >160). E. coli was confirmed present in 67.74% of all the well water and 71.43% of the entire stream. 86.11% of all the isolates were resistant to beta-lactam class of antibiotics, nitrofurantoins (11.11%), aminoglycosides (2.78%) and fluoroquinolones (2.78%). 2.78% were resistant to three classes of antibiotics (nitrofurantoins, aminoglycosides and beta-lactam). 30.56% were resistant to ampicillin, while all the isolates were sensitive to ciprofloxacin.

Conclusion: There is need for good hygiene practices and indiscriminate use of antibiotics should be discouraged, in order to reduce the release of antibiotic resistant E. coli to the environment.