Escherichia coli is a Gram-negative bacteria that causes various diseases, including pneumonia, urinary tract infections, and diarrhoea. The present work is an effort to study antimicrobial resistance pattern in this bacteria. Clinical samples (6840) were collected from King Fahd Hospital in Madinah, Saudi Arabia and screened for E. coli strains. Of all positive samples obtained from different clinical sources, about 3% isolates represented E. coli and 71.6% of these were collected from clinical samples of male patients. E. coli isolates were recovered from sputum (20.58%), wound (55.88%), and catheters tips (9.31%) representing about 86% of all clinical specimens. Antimicrobial susceptibility pattern of the E. coli isolates to twelve different antimicrobials revealed that all the isolates (100%) were susceptible to imipenem, amikacin, and aztreonam. Cefoxitin, ceftazidime and ciprofloxacin showed a sensitivity of 98.7%. This was followed by gentamycin (98.6%), piperacillin (95.7%), cotrimoxazole (92.3%), cephalothin (91.4%), and Augmentin (91.1%). Ampicillin showed the least susceptibility of 87.5%. Hence, cotrimoxazole, Augmentin, and ampicillin should be prescribed with care in order to avoid increasing resistance patterns in E. coli. Results also demonstrate that frequency of E. coli infections was highest during summer and winter seasons representing about 30% each. Autumn season, which coincided with the season of pilgrimage, recorded about 22% of infections while spring season had the least recorded percentage with only 17% of infections. This study is therefore a step towards the generation of national data on the prevalence of antimicrobial resistance patterns of E. coli.

Keywords: Escherichia coli, antimicrobial susceptibility pattern, multi-drug-resistance, antimicrobials