title: First report of class 1 and class 2 integrons in multidrug-resistant Klebsiella pneumoniae isolates from northwest Iran.
abstract: We investigated the prevalence of multidrug resistance, production of  extended-spectrum β-lactamases (ESBLs), and presence of class 1 and 2 integrons in 150  clinical isolates of Klebsiella pneumoniae from northwest Iran by performing phenotypic  confirmatory tests and polymerase chain reaction (PCR) analysis. Of the 150 isolates, 149  (99.3%) were multidrug resistant (MDR). Of the MDR isolates, 124 (83.2%) were ESBL positive.  The results of the PCR analysis showed that 117 (78.5%) and 20 (13.4%) MDR K. pneumoniae  isolates carried intI1 and intI2, respectively, and 16 (10.7%) MDR K. pneumoniae isolates  contained the integrase genes of both class 1 and class 2. Resistance of the isolates to  gentamicin, tetracycline, ceftazidime, cephalothin, chloramphenicol, and nalidixic acid was  observed to be significantly associated with the presence of class 1 integrons; however, the  resistance to tetracycline was observed to be associated with the presence of class 2 integrons  alone. This study showed that integrons are widely prevalent in the clinical isolates of  K. pneumoniae from northwest Iran, and that they may be playing an important role in  attributing multidrug resistance to the clinical K. pneumoniae isolates. To the best of our  knowledge, this is the first report showing the presence of class 1 and class 2 integrons  in MDR K. pneumoniae isolates from clinical settings in northwest Iran.
authors.affiliation: Research Center of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. rezaee＠tbzmed.ac.ir
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ahangarzadeh Rezaee
authors.forename: Nastaran
authors.initials: N
authors.lastname: Langarizadeh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Aghazadeh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006801:Humans; D032023:Integrons / Q000235:genetics*; D007492:Iran / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases