title: Prevalence of OmpK35 and OmpK36 porin expression in beta-lactamase and non-betalactamase- producing Klebsiella pneumoniae.
abstract: BACKGROUND
  The aims of this study were to confirm the presence of OmpK35 and OmpK36 in extended-spectrum beta-lactamase-producing and nonextended-spectrum beta-lactamase-producing Klebsiella pneumoniae and to determine the relationship between porin expression and resistance to third-generation cephalosporins.
  
  
  METHODS
  Fifty-two K. pneumoniae isolates were obtained and analyzed for extended-spectrum beta-lactamase and for OmpK35 and OmpK36.
  
  
  RESULTS
  Twenty-two (42.3%) isolates of K. pneumoniae were extended-spectrum beta-lactamase producers. The OmpK35 profile in K. pneumoniae producing extended-spectrum beta-lactamase showed the presence of porin protein in ceftazidime-sensitive K. pneumoniae (six isolates), and the OmpK36 profile in K. pneumoniae producing extended-spectrum beta-lactamase revealed isolates sensitive to cefotaxime (n = 8) and ceftriaxone (n = 6). All nonextended-spectrum beta-lactamase-producing K. pneumoniae showed the presence of OmpK35 and OmpK36 porin proteins.
  
  
  CONCLUSIONS
  The presence of OmpK35 is mostly related to ceftazidime susceptibility and less to cefotaxime and ceftriaxone susceptibility, while OmpK36 expression is seen more often in cefotaxime-sensitive isolates. OmpK35 and OmpK36 indicate nonextended-spectrum beta-lactamase producing strains, and their presence is important when selecting an antimicrobial agent.
authors.affiliation: Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam.
authors.forename: Pegah
authors.initials: P
authors.lastname: Shakib
authors.forename: Sobhan
authors.initials: S
authors.lastname: Ghafourian
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zolfaghary
authors.forename: Reza
authors.initials: R
authors.lastname: Hushmandfar
authors.forename: Reza
authors.initials: R
authors.lastname: Ranjbar
authors.forename: Nourkhoda
authors.initials: N
authors.lastname: Sadeghifard