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Volume 2015 (2015), Article ID 518167, 7 pages
Research Article

Prevalence of Plasmid-Mediated Quinolone Resistance Determinants and OqxAB Efflux Pumps among Extended-Spectrum -Lactamase Producing Klebsiella pneumoniae Isolated from Patients with Nosocomial Urinary Tract Infection in Tehran, Iran

1Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran 1985717443, Iran
2Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran 1985717443, Iran
3Department of Medical Laboratory Sciences, Faculty of Allied Medicine, Qazvin University of Medical Sciences, Qazvin 1651135779, Iran
4Department of Medical Mycology, Pasteur Institute of Iran, Tehran 1316943551, Iran

Received 3 June 2015; Accepted 21 July 2015

Academic Editor: Joaquim Ruiz

Copyright © 2015 Mehdi Goudarzi 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.


Objective. Plasmid-mediated quinolone resistance (PMQR) plays an important role in the development of clinical resistance to quinolone. The aim of this study was to investigate PMQR determinants among extended-spectrum β-lactamases- (ESBL-) producing Klebsiella pneumoniae recovered from patients with nosocomial urinary tract infection (UTI). Methods. A total of 247 ESBL-producing K. pneumoniae isolates were collected from 750 patients with UTI. ESBL production was confirmed by double disc synergy test and combined disc diffusion test. The prevalence of PMQR determinants among ESBL-producing K. pneumoniae was assessed using PCR method. Results. The rates of resistance to antimicrobial agents in present study varied from 14.2% to 98.8%. In comparison with other PMQR genotypes, the frequency of aac(6′)-Ib (68.8%) was strikingly high. Of the 247 isolates tested, qnrA, qnrB, qnrS, and qepA genes were present in 3.6%, 1.6%, 1.2, and 2%, respectively. oqxA and oqxB were detected in 56.7% and 54.6% of isolates. The predominant coexisting ESBL and PMQR profile among our isolates included and aac(6′)-Ib, oqxA, oqxB (28.3%) and , and aac(6′)-Ib, oqxA, and oqxB (19.4%) profile.  Conclusion. Given the linkage observed between resistance to quinolones and beta lactam antibiotics, therapeutic protocol with fluoroquinolones and beta lactam antibiotics should be seriously revised in Tehran hospitals.