Molecular characterization of class 1 integrons and gene cassettes in multidrug resistant (MDR) Klebsiella spp. isolated from hospitalized and outpatients in Iran, 2009

Klebsiella is one of the most common species 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 evaluated in clinical Klebsiella isolates in Besat University hospital of Sanandaj, Iran. Isolates identification has done by API20E. Antibiotic susceptibility testing and MIC has done for MDR isolates. For investigating class 1 integrons and gene cassettes, PCR by intI1 integrase, 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. 35 isolated Klebsiella spp. included 29 K. pneumoniae and 6 K. oxytoca. All the isolates were susceptible to carbapenems. Sequencing for prevalent bands showed arr-5, orfD-aacA4 and aad5- dfrA17. Accession numbers for gene cassette were JN222800.1, JN222799.1 and JN222798.1, by order. PFGE Analysis showed 18 clusters in k. pneumonia with clonality relatedness in some cases but no relatedness among K. oxytoca isolates. 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 potential in the resistance development in our clinical settings.