Table of Contents
Epidemiology Research International
Volume 2011, Article ID 698705, 8 pages
Research Article

Dissemination and Molecular Epidemiology of KPC-Producing Klebsiella pneumoniae Collected in Puerto Rico Medical Center Hospitals during a 1-Year Period

1Department of Microbiology and Medical Zoology, School of Medicine, University of Puerto Rico, P.O. Box 365067, San Juan, PR 00936-5067, USA
2Department of Medical Microbiology, School of Medicine, Creighton University, Omaha, NE 68178, USA
3Department of Pathology and Laboratory Medicine, School of Medicine, University of Puerto Rico, San Juan, PR 00936-5067, USA

Received 25 August 2011; Revised 29 September 2011; Accepted 3 October 2011

Academic Editor: H. T. Sørensen

Copyright © 2011 Iraida E. Robledo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.