The prevalence of extended-spectrum betalactamases among uropathogenic Escherichia coli isolates from Ibn Sina hospital of Delfan, Lorestan

The most common cause of resistance to beta-lactam antibiotics in Escherichia coli is resulted from beta-lactamase enzymes production. Unfortunately, some of these enzymes, called “Extended-spectrum betalactamases” are able to make inactive new third-generation cephalosporins as well as aztheronam. Several studies have reported the prevalence of ESBLs in Iran as well as other regions of the world. Thus, the aim of this study was to determine antimicrobial susceptibility pattern and the prevalence of the ESBLs among uropathogenic E.coli isolated from Delfan city, Lorestan (2012). In this study, one–hundred uropatogenic E.coli isolates were collected and identified from hospitalised patients in Ibn Sina hospital in Delfan city. Antimicrobial susceptibility testing of the isolates were performed on Muller-Hinton agar plates using disk diffusion method. Phenotypic assay of ESBLs production was accomplished using cefotaxime, ceftazidime and cefpodoxime disks alone and in combination with Clavulanic acid (combined disk). Among 100 collected isolates, the most resistance were seen to ampicillin (85%) and also, there was no resistance to imipenem (0%). In addition, the results of the combined disk assay showed that 80% of the isolates were ESBLs positive. The results of this study and other studies have indicated that incidence of ESBLs in Iran as well as Delfan city is high. Therefore, determination of ESBLs positive isolates by microbiology laboratories using combined disk method, limited use of beta-lactams and the non-empirical therapy of infectious diseases in hospitalised patients as far as possible can notably improve the efficiency of beta-lactams antibiotics