title: Detection of OqxAB efflux pumps, OmpK35 and OmpK36 porins in extended-spectrum-β-lactamase-producing Klebsiella pneumoniae isolates from Iran.
abstract: OBJECTIVE
  The aim of this study was the detection of OqxAB efflux pumps, OmpK35 and OmpK36 porins among extended-spectrum-β-lactamase-producing Klebsiella pneumoniae isolates from Iran.
  
  
  METHODS
  This study was conducted with 83 K. pneumoniae isolates from two hospitals in Tehran, Iran. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and Broth Microdilution methods according to CLSI guidelines. The OqxAB , blaTEM, blaSHV and blaCTX-M genes were detected by PCR and sequencing methods.The outer membrane porins OmpK35 and OmpK36 were analyzed by SDS-PAGE, PCR and sequencing methods.
  
  
  RESULTS
  Among the 83 K. pneumoniae strains, 48 (57.5%) were ESBL positive. The existence of blaTEM, blaSHV and blaCTX-M was detected in 24 (50%), 30 (62.5%) and 28 (58.33%) ESBL-producing isolates respectively. The prevalence of both oqxA and oqxB detected in K. pneumoniae was high: 50 (60.2%) and 50 (60.2%), respectively. OmpK35 was detected in 30 (62.5%) while OmpK36 was found in 35 (72.91%) out of 48 ESBL-producing isolates. In this study, fosfomycin and tigecycline were more active than other antibiotics.
  
  
  CONCLUSIONS
  The prevalence of beta-lactamase-producing K. pneumoniae detected in this study is of great concern and highlights the need of infection control measures including antibacterial management and prompt identification of beta-lactamase-producing isolates.
authors.affiliation: Department of Microbiology, Kurdistan University of Medical Sciences, Sanandaj, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Taherpour
authors.affiliation: Department of Microbiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Hashemi
keywords: Klebsiella pneumoniae; OqxAB; outer membrane porins; β-Lactamases