title: Molecular characterization of class 1 integrons and gene cassettes in multidrug resistant (MDR) Klebsiella spp. isolated from hospitalized and outpatients in Iran, 2009.
abstract: OBJECTIVE
  Klebsiella species are of the most common bacteria involved in nosocomial and urinary tract infections. Genetic elements such as class 1 integrons have an important role in the resistance development. In this study, the share of class 1 integrons, the genetic characterization of the integron cassettes and PFGE profiles of the clinical Klebsiella isolates are evaluated in Besat University hospital of Sanandaj, Iran.
  
  
  METHODS
  Isolates from 17890 clinical specimens were identified by API20E. Antibiotic susceptibility testing and MIC were done for MDR isolates. For investigating class 1 integrons and gene cassettes, PCR by intI1 integrase and 5'-CS/3'-CS were performed. Integrated gene cassettes were analyzed by PCR-RFLP and sequencing. Pulsed-Field Gel Electrophoresis was carried out for studying of clonality outbreak of isolates.
  
  
  RESULTS
  Thirty five Klebsiella spp. were isolated and included 29 K. pneumoniae and 6 K. oxytoca. All the isolates were susceptible to carbapenems while other antibiotics showed high resistant profile. In all Klebsiella spp. PCR for intI1 integrase and 5'-CS/3'-CS were positive (100%). Sequencing for prevalent bands of internal variable regions between 5'-CS/3'-CS showed arr-5, orfD-aacA4 and aad5- dfrA17. PFGE Analysis showed 18 clusters in K. pneumoniae with clonality relatedness in some cases but no relatedness among K. oxytoca isolates.
  
  
  CONCLUSIONS
  High prevalence of class 1 integron carrying gene cassettes confirms that integron-mediated antimicrobial gene cassettes are important in Klebsiella spp. resistance profile. Clone diffusions of MDR Klebsiella spp. which harbor class 1 integrons have threaten the potential in the resistance development in our clinical settings.
authors: Department of Microbiology, School of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.
authors: Himen
authors: H
authors: Salimizand
authors: Fereshteh
authors: F
authors: Shahcheraghi
authors: Enayatollah
authors: E
authors: Kalantar
authors: Farzad
authors: F
authors: Badmasti
authors: Seyed Fazlollah
authors: SF
authors: Mousavi
keywords: Klebsiella spp.; class 1 integrons; multidrug resistante (MDR)