Abstract

Betal-lactam antibiotics are the most frequently prescribed antibiotics. Emerging resistance to these antibiotics among gram-negative bacilli limited their utility. This study was done to determine the frequency of extended spectrum beta-lactmase (ESBLs) producing Escherichia coli and Klebsiella pneumoniae isolated from urine in Milad Hospital of Tehran. This study was done on 735 urine gram-negative bacilli isolates including 620 strains of E. coli and 115 strains of K. pneumoniae in microbiology laboratory of Milad Hospital in Tehran, Iran. ESBls resistance was detected in 132 (21%) of isolates of E. coli and 18 (12%) in those with K. pneumoniae. Of 150 patients which had positive ESBLs isolates, 104 were outpatients and 46 others were hospitalized. Nearly 80% ESBls isolates were resistant to co-trimoxazole and nitrofuantion was the most effective antibiotic against ESBLs producing isolates. Our study revealed that there is a high frequency isolates of ESBls producing strains of E. coli and K. pneupmiae in both community and hospital. This has a significant implication for patients’ management. Further drug resistance surveillance in our hospitals and molecular characteristics of ESBls isolates in our country is necessary.

Key words: Extended spectrum beta-lactamase (ESBLs), Escherichia coli,Klebseilla pneumonia, urinary tract.