determination of antimicrobial resistance pattern and detection of blatem gene among clinical isolates of escherichia coli

background :    unfortunately, antibiotic resistance has become an increasingly critical problem in many countries like iran. since there are very few published data on antibiotics resistance in alborz province, the aim of this study was to survey the pattern of antimicrobial resistance and prevalence detection of tem-type beta-lactamases among clinical isolates of escherichia coli using universal primers.   methods :     the study was performed on 83 clinical escherichia coli strains collected from hospitals and clinical laboratories. antimicrobial susceptibility was performed using kirby-bauer disk diffusion method against common antibiotics. isolates were also screened for the production of extended spectrum beta-lactamases (esbls) by double disk synergy test (ddst). positive isolates were evaluated by pcr analysis for the tem family of esbls genes.   results :    isolates showed the highest resistance to amoxicillin (83%), whereas nitrofurantoin was the most effective drug, with only 8.4% resistance. the frequency of multi drug resistance (mdr) to more than 5 antibiotics was 79.5% (66 strains). esbl screening of e. coli strains by ddst showed that out of 83 strains, 33 isolates were esbl positive. based on the pcr results 61 percent of phenotypic esbl positive e. coli isolates possessed a single gene encoding a tem type esbl. conclusion :   as the results of this study indicate, multidrug resistance is an increasing therapeutic concern and treatment requires further attention to the results of susceptibility tests. as antibiotic options in the treatment of esbl-producing organisms are extremely limited, molecular screening by laboratories is suggested to reduce the risk of therapeutic defeat.