%0 Journal Article
%T Dissemination and Molecular Epidemiology of KPC-Producing Klebsiella pneumoniae Collected in Puerto Rico Medical Center Hospitals during a 1-Year Period
%A Iraida E. Robledo
%A Guillermo J. V芍zquez
%A Ellen S. Moland
%A Edna E. Aquino
%A Richard V. Goering
%A Kenneth S. Thomson
%A Mar赤a I. Sant谷
%A Nancy D. Hanson
%J Epidemiology Research International
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/698705
%X During a 2003-2004 PCR-based surveillance study conducted in 6 Puerto Rico Medical Center hospitals, 27/92 multi-beta-lactam-resistant Klebsiella pneumoniae strains were identified as carbapenemase (KPC) positive in 4 hospitals. The objectives of this study were to identify the KPC variants, their genetic relatedness, and any other beta-lactamases present. Susceptibility testing, pulsed field gel electrophoresis (PFGE), isoelectric focusing, PCR, and DNA sequencing were performed. KPC variants -2, -3, -4, and -6 were identified. Additional beta-lactamases detected were TEM, DHA, OXA-9 and -30. Antimicrobial susceptibility to carbapenems varied depending on the KPC variant. Five PFGE genetically related groups were identified in 15 isolates and 12 unrelated types. PFGE profiles suggested that both clonal and horizontal transfer are contributing to the dissemination of these isolates among the various hospitals. Comparison of the 2003 and a 2009 surveillance studies showed a significant increase in the KPC-positive K. pneumoniae isolates in the latter. 1. Introduction The detection of carbapenemase producing isolates is a major clinical concern since carbapenems are the drug of choice for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. KPC stands for Klebsiella pneumoniae carbapenemase, which are classified as Bush subgroup 2f Class A serine-based enzymes, inhibited by clavulanic acid and tazobactam. They are capable of hydrolyzing beta-lactam antibiotics of all classes [1每3]. KPC-producing isolates, which were initially restricted to hospitals located in the northeastern USA, have recently been detected in other USA regions and in other countries worldwide [1每3]. They have been identified in K. pneumoniae, other Enterobacteriaceae, and recently in Pseudomonas aeruginosa, and Acinetobacter baumannii [1每9]. Serious nosocomial outbreaks have been associated with these KPC-positive organisms [10每14]. This carbapenemase-encoding gene is found on transferable plasmids associated with transposon Tn4401 [15, 16]. Ten KPC variants (KPC-2 to -11) have been described so far (http://www.lahey.org/studies/) differing between them in 1- or 2-point mutation [1每3]. KPC-producing isolates may be difficult to detect since elevated carbapenem MIC are not always evident [2, 17]. This poses a major therapeutic challenge, as treatment may be inadequate and therefore may lead to significant increase in patients＊ mortality, morbidity, and hospitalization costs. To improve the detection of KPC-positive Enterobacteriaceae, the Clinical and
%U http://www.hindawi.com/journals/eri/2011/698705/