Full Length Research Paper

Antibiotic susceptibility pattern and ESBL prevalence in nosocomial Escherichia coli from urinary tract infections in Pakistan

Farhat Ullah¹*, Salman Akbar Malik¹ and Jawad Ahmed²

¹Department of Biology, Quaid-i-Azam University, Islamabad, Pakistan.

²Department of Pathology, Khyber Medical College, Peshawar, Pakistan.

*Corresponding author. E-mail: farhataziz80@hotmail.com. Tel: 00923339361513.

Accepted 9 April, 2009

Urinary tract infections (UTI) are the most prevalent infections worldwide, mostly caused by Escherichia coli. These bacteria also produce enzymes called extended spectrum b-lactamases (ESBL) which render penicillins and cephalosporins inactive. The present study included 116 E. coli, isolated from urine of in-patients suffering from UTI. Antibiotic susceptibility testing and ESBL detection were carried out according to Clinical Laboratory and Standards Institute (CLSI) criteria. Fifteen antibiotics were tested in this study. A total of 66 (56.9%) isolates were found to be ESBL producers. A total of 83% isolates were resistant to 4 or more antibiotics. Imipenem and meropenem showed high potency with 98 and 97% isolates being susceptible, respectively. Susceptibility to gentamicin was 48%, kanamycin 43%, both ofloxacin and enoxacin 38%, ciprofloxacin 35%, doxycycline 18% and to co-trimoxazole only 17%. This study reveals that E. coli isolated from UTI in this region are multi-drug resistant and produce ESBL in large proportions.

Key words: Antibiotic resistance, Escherichia coli, Extended Spectrum b-Lactamase, Urinary Tract Infections.