prevalence of ctx-m genes in bacterial strain isolated from patients hospitalized in icu units in the city of qom, iran

background :  pathogenic bacteria because of beta-lactam antibiotic resistance genes are dangerous to society. this resistance due to esbl genes, plasmids and transposons that by receiving or mutation occurs. the most important factor beta-lactam antibiotic resistance is beta lactamase enzymes. the purpose of this study was to evaluate the frequency of hospital opportunistic pathogenic bacteria producing esbl and ctx-m genes identified are molecular methods.   methods :  in this study, 500 isolates from patients in the icu of hospitals in the city of qom was diagnosed by standard biochemical tests. combined disk test for isolated resistant strains of esbl was performed in order to identify. then, strains producing esbl, dna extraction and ctx-m genes were detected by pcr.   results :    a total of 500 strains isolated, 20 strains (51.28%) of p. aeruginosa strains, 40 strains (62.5%) of e. coli strains, 38 strains (48.1%) of k. pneumoniae strains, 8 strains (33.33%) a. baumannii bacteria strains and 4 strains (23.52%) of the strains of enterobacter were carrying ctx-m genes.   conclusion :  this study represents a high percentage of beta-lactamase resistance among hospital opportunistic pathogens bacteria. due to the high prevalence of antibiotic resistance carried out detailed antibiogram tests in infections caused by esbl-producing organisms is necessary.