The frequency and antimicrobial sensitivity pattern of extended spectrum -lactamase (ESBLs) producing gram negative bacilli isolated from urine in a tertiary care hospital of Pakistan

Urinary tract infections (UTIs) are one of the most common bacterial infections in humans, both in the community and the hospital settings. An extensive use of β -lactam antibiotics in hospitals and community has created major resistance problem leading to increased morbidity, mortality and health-care costs. Local knowledge of antimicrobial susceptibilities of these organisms is important for implementation of effective hospital anti-infective policies. The objective of the study was to determine the prevalence of ESBL producers along with their antimicrobial sensitivity pattern in the urinary isolates of Gram negative bacilli. The study was carried out in the Department of Microbiology, Army Medical College, looking after an 1100 bedded tertiary care hospital from December 2009 to November 2010. A total of 826 clinical isolates of Gram negative bacilli were recovered from the routine clinical samples of urine from the inpatient and outpatient departments of the hospital. Three hundred and sixty four (364) ESBL producers were identified from these isolates. Escherichia coli was the most frequent ESBL producer in this group followed by Klebsiella pneumoniae and Enterobacter spp. Carbapenems were found to be the most effective drug followed by Amikacin and Nitrofurantoin. The high prevalence of ESBL producers in the urinary isolates in our study warrants the need for judicious use of antibiotics to control the spread of antibiotic resistance in these bacteria.   Key words: Urinary isolates, gram negative bacilli, ESBL, antibiotic resistance.