1. Prevalence of quinolone resistance mechanisms in Enterobacteriaceae producing acquired AmpC β-lactamases and/or carbapenemases in Spain.
- Author
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Machuca J, Agüero J, Miró E, Conejo MDC, Oteo J, Bou G, González-López JJ, Oliver A, Navarro F, Pascual Á, and Martínez-Martínez L
- Subjects
- Bacterial Proteins genetics, Enterobacteriaceae enzymology, Enterobacteriaceae genetics, Enterobacteriaceae isolation & purification, Enterobacteriaceae Infections epidemiology, Genes, Bacterial, Humans, Nalidixic Acid pharmacology, R Factors genetics, Spain epidemiology, beta-Lactam Resistance genetics, beta-Lactamases genetics, Bacterial Proteins metabolism, Drug Resistance, Multiple, Bacterial genetics, Enterobacteriaceae drug effects, Enterobacteriaceae Infections microbiology, Fluoroquinolones pharmacology, beta-Lactamases metabolism
- Abstract
Background: Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates., Methods: The presence of chromosomal- and plasmid-mediated quinolone resistance mechanisms [mutations in the quinolone resistance determining region (QRDR) of gyrA and parC and qnr, aac(6')-Ib-cr and qepA genes] was evaluated in 289 isolates of acquired AmpC β-lactamase- and/or carbapenemase-producing Enterobacteriaceae collected between February and July 2009 in 35 Spanish hospitals., Results: Plasmid mediated quinolone resistance (PMQR) genes were detected in 92 isolates (31.8%), qnr genes were detected in 83 isolates (28.7%), and the aac(6')-Ib-cr gene was detected in 20 isolates (7%). qnrB4 gene was the most prevalent qnr gene detected (20%), associated, in most cases, with DHA-1. Only 14.6% of isolates showed no mutations in gyrA or parC with a ciprofloxacin MIC of 0.5mg/L or higher, whereas PMQR genes were detected in 90% of such isolates., Conclusion: qnrB4 gene was the most prevalent PMQR gene detected, and was significantly associated with acquired AmpC β-lactamase DHA-1. PMQR determinants in association with other chromosomal-mediated quinolone resistance mechanisms, different to mutations in gyrA and parC (increased energy-dependent efflux, altered lipopolysaccharide or porin loss), could lead to ciprofloxacin MIC values that exceed breakpoints established by the main international committees to define clinical antimicrobial susceptibility breakpoints., (Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)
- Published
- 2017
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