Background: The major faecal coliform is Escherichia coli which contaminates the drinking water from human and animal faecal waste. In developing regions drinking water is a vital source of microbiological pathogens. Multi-drug resistant (MDR) is defined as resistance to one or more antibiotic groups. An E. coli count greater than 4/dl in municipal drinking water is indicative of unacceptable fecal contamination.

Aim: To find out the frequency of MDR E. coli in water system of Lahore, Pakistan.

Methodology: Drinking water was collected from different towns of Lahore. The samples were processed using Membrane Filtration Technique. In the present study, Multidrug Resistant E.coli was isolated and antibiotic resistant pattern was seen against 16 most commonly antimicrobials, using Kirby Bauer disc diffusion method.

Results: Total 100 water samples were collected, frequency of Escherichia coliisolated was 27% and frequency of MDR E.coli was 19%. The highest resistance showed by the organism towards Ampicillin (AMP) 21(81.48%), Augmentin (AMC), and Ceftazidime (CAZ) 14(51.85%) respectively. In this study also frequency of Extended Spectrum β-Lactamases were seen. Most common organisms isolated were E. coli 7% and Klebsiella 5%. Frequency of other coliforms isolated from drinking water other than E. coli was Klebsiella species 26%, Pseudomonas species 27%, Enterobacter 7%, Citrobacter species 8% and Acinetobacter species 5%.

Conclusion: This study revealed that drinking water of Lahore city is heavilycontaminated with pathogenic microorganisms. A high proportion of antibiotic resistant is due to overuse of antibiotics, in patients with mild infections and secretion of these resistant bacteria from patients to environment. One of the reasons could be the mixing of sewage lines with drinking water supply. So, there is solely requirement for further studies for the identification of the sources for these contaminants.

Keywords: Isolates, E. coli, Klebsiella, Multi-drug resistant (MDR)