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

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. Isolates from 17890 clinical specimens were identified byAPI20E. Antibiotic susceptibility testing 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. Thirty five Klebsiella spp. were isolated and included 29 K. pneumoniae and six K. oxytoca. All the isolates were susceptible to carbapenems while other antibiotics showed high resistant profile. In all Klebsiella spp. PCR for intl1 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- dfrA 17. PFGE Analysis showed 18 clusters in K. pneumoniae 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 the potential in the resistance development in our clinical settings

Metallo- beta-lactamases among multidrug resistant [MDR] gram negative bacteria isolated from clinical specimens during 2009 in Sanandaj, Kurdistan province

Today, there are numerous reports about emerging multi drug resistant gram negative bacteria all around the world, especially in ICUs. Rarely, Metallo-beta-lactamase [MBL] enzymes are responsible for these cases. Study of MBLs for diagnosing and preventing distribution of the origin of infection are critical issues. In addition, we would like to compare the efficacy of Iranian and foreign- made antibiotic disks. During 2009 all entered clinical specimens to the laboratory tested for detecting gram negative bacteria. Isolated bacteria were tested by Kirby-Bauer method to antibiotic susceptibility test by Iranian and foreign [MAST] disks. For gram negative carbapenem resistant isolates, PCR technique used to detect VIM, GIM, and SIM variants of MBLs. During one year, 17890 clinical specimens referred Besat laboratory. The most specimen was Urine [8172] followed by blood culture [5190] that in which 1110 gram negative and positives isolated. Out of which, 778 [70%] of isolates were gram negatives. MDR gram negatives were 157 [20.2%]. Imipenem and meropenem were the most efficient antibiotics [all susceptible] and ceftriaxone was the least [19% susceptible]. E. coli was the most prevalent isolate. 79 Gram negative isolates [10.1%] were resistant to Iranian-made discs but all susceptible for foreign ones. All 79 isolates were tested by PCR for MBL genes, that, all were negative. Besides, Iranian imipenem and cefepime disks have had distinguishable difference in susceptibility of isolates. Fortunately, none of gram negative isolates were MBL producer, which revealed no colonization of MBL producing bacteria. Iranian-made disks appear efficient except for imipenem and cefepime.