high prevalence of multiple drug resistance among esbls-producing klebsiella pneumoniae isolated from hospitalized patients in isfahan, iran

background :   this study was to evaluate the prevalence of ctx-mand tem type esbls-producing k. pneumoniae and determination of mdr, xdr, and pdr phenotypes of these isolates as well as find out the genetic relationship and molecular typing of these isolates using phenotypic and genotypic methods. methods :   non-repetitive 96 k. pneumonia isolates were isolated from hospitalized patients in al-zahra hospital of isfahan, iran. the antibiotic susceptibility test was assessed for 20 antibiotics using kirby-bauer disk diffusion method. the frequency of esbl-producing isolates was determined by phenotypic confirmatory test. all esbls-producing isolates were assessed for bla tem and bla ctx-m genes using pcr method. molecular typing was performed by enterobacterial repetitive intergenic consensus sequence-based pcr (eric-pcr). results :   among 96 isolates, 58 isolates (60.4%) were esbl-producers. in this study, 85.7% and 30.3% of esbl-producing isolates showed mdr and xdr phenotypes, respectively. no pdr isolate was found. pcr amplification on esbl-producing isolates showed that 47 (81%) isolates were carried bla tem gene, while bla ctx-m was detected in all isolates (100%). eric-pcr typing was characterized the high genetic similarity among esbl-producing k. pneumonia isolates and revealed 32 band pattern for the isolates.   conclusion :  this study showed high prevalence of important esbl genes ( bla ctx-m and bla tem genes) among the k. pneumoniae isolated from in-patients. constant following of esbls, also identification of their types, in bacteria isolated from hospitalized patients has an important clinical impact. it can provide valuable information for the choice of appropriate antibacterial therapy and decrease of antibiotic resistance.