en Microbiology Microbiology پژوهشي Research <div><strong>Introduction:</strong> Recentlly, resistance to antibiotics has increased and antibiotic-resistant strains producing extended-spectrum beta-lactamases (ESBLs) have emerged among Enterobacteriaceae, mainly in Escherichia coli (<em>E. coli</em>). In this study we aimed to determine phenotypic and genotypic ESBL production in isolated <em>E. coli</em> from women with urinary tract infection (UTI).<br> <strong>Materials and Methods:</strong> In total, 92 <em>E. coli </em>isolates were collected from patients with UTI. The antimicrobial susceptibility of all <em>E. coli</em> isolates were investigated. Morover, Mast D68C test and polymerase chain reaction (PCR) were used for phenotypic and genotypic investigation of ESBLs in<ins cite="mailto:1" datetime="2021-03-10T08:17"> the</ins> studied isolates.<br> <strong>Results:</strong> Totally, 92 isolates of <em>E. coli</em> were investigated, <ins cite="mailto:1" datetime="2021-03-10T08:18">among </ins>which 51 (55.4%) isolates were resistant to cefotaxime/ceftazidime. Th<ins cite="mailto:1" datetime="2021-03-10T08:18">e</ins><del cite="mailto:1" datetime="2021-03-10T08:18">i</del>s<ins cite="mailto:1" datetime="2021-03-10T08:18">e</ins> resistante isolates were included in the study. Among the resistant isolates, 40 (78.4%) cases were ESBL producers. Moreover, all <ins cite="mailto:1" datetime="2021-03-10T08:18">the </ins>40 isolates were observed with both CTX-M-15 and CTX-M-14 resistance genes.<br> <strong>Conclusion: </strong>In general, <del cite="mailto:1" datetime="2021-03-10T08:19">high </del><ins cite="mailto:1" datetime="2021-03-10T08:19">increasing </ins>prevalence of ESBL producer <em><ins cite="mailto:1" datetime="2021-03-10T08:19">E. coil</ins></em> isolates <del cite="mailto:1" datetime="2021-03-10T08:19">of <em>E. coil</em> </del>is a serious problem in the investigated region. Therefore, development of a rapid and simple method is essential <del cite="mailto:1" datetime="2021-03-10T08:21">to </del><ins cite="mailto:1" datetime="2021-03-10T08:21">for the </ins>identification of various ESBL producer isolates.</div> Urinary tract infection, Escherichia coli, Extended-spectrum β-lactamase, CTX-M 1 7 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-503-5&slc_lang=en&sid=1 Alireza Jahantabi alirezajahantabi@gmail.com 10031947532846007708 10031947532846007708 No Department of Biological Sciences, Islamic Azad University, Tehran North Branch, Tehran, Iran Farzaneh Hosseini hosseinmicrobiology@gmail.com 10031947532846007709 10031947532846007709 Yes Department of Biological Sciences, Islamic Azad University, Tehran North Branch, Tehran, Iran Mohammad Asgharzadeh Asgharzadeh.Mohammad@gmail.com 10031947532846007710 10031947532846007710 No Department of Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran Abbas Akhavan Sepehi akhavansepahy@gmail.com 10031947532846007711 10031947532846007711 No Department of Biological Sciences, Islamic Azad University, Tehran North Branch, Tehran, Iran Hossein Samadi Kafil Samadi.hossein@yahoo.com 10031947532846007712 10031947532846007712 No Department of Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran