Giuseppe
Emeritus
[Source: PLoS ONE, full text: (LINK). Abstract, edited.]
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Prevalence of Plasmid-Mediated Quinolone Resistance and Aminoglycoside Resistance Determinants among Carbapeneme Non-Susceptible Enterobacter cloacae
Shifeng Huang<SUP>#</SUP>, Wei Dai<SUP>#</SUP>, Shan Sun, Xiaojiao Zhang, Liping Zhang<SUP>*</SUP>
<SUP></SUP>
Department of Laboratory Medicine, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
Abstract
Background
Simultaneous resistance to aminoglycosides and fluoroquinolones in carbapeneme non-susceptible (CNS) isolates will inevitably create problems. The present study was performed to characterize the prevalence of the plasmid-mediated quinolone resistance determinants (QRDs) and aminoglycoside resistance determinants (ARDs) among the CNS Enterobacter cloacae (E. cloacae) isolates in a Chinese teaching hospital, and to acquire their molecular epidemiological characteristics.
Methods
The β-lactamases genes (including class A carbapenemase genes bla<SUB>KPC</SUB> and bla<SUB>SME</SUB>, metallo-β-lactamase genes (MBLs) bla<SUB>IMP</SUB>, bla<SUB>VIM</SUB> and bla<SUB>NDM</SUB>, and extended spectrum β-lactamases (ESBLs),bla<SUB>CTX-M</SUB>, bla<SUB>TEM</SUB> and bla<SUB>SHV</SUB>), QRDs (including qnrA, qnrB, qnrS and aac(6′)-Ib-cr) and ARDs (including aac(6′)-Ib, armA and rmtB) of these 35 isolates were determined by PCR and sequenced bidirectionally. The clonal relatedness was investigated by pulsed-field gel electrophoresis (PFGE).
Results
Of the 35 isolates, 9 (25.7%) harbored a carbapenemase gene; 23 (65.7%) carried ESBLs; 24 (68.6%) were QRD positive; and 27 (77.1%) were ARD positive. Among the 5 bla<SUB>IMP-8</SUB> positive strains, 4 (80%) contained both ESBL and QRD genes, and all the 5 (100%) harbored ARD genes. Of the 23 ESBLs positive isolates, 6 (26.1%) were carbapenemase positive, 14 (60.9%) were QRD positive, and 18 (78.3%) were ARD positive. PFGE revealed genetic diversity among the 35 isolates, indicating that the high prevalence of CNS E. cloacae isolates was not caused by clonal dissemination.
Conclusion
QRD and ARD genes were highly prevalent among the CNS E. cloacae isolates. Multiple resistant genes were co-expressed in the same isolates. The CNS E. cloacae isolate co-expressing bla<SUB>NDM-1</SUB>, bla<SUB>IMP-26</SUB>, qnrA1 and qnrS1 was first reported.
Citation: Huang S, Dai W, Sun S, Zhang X, Zhang L (2012) Prevalence of Plasmid-Mediated Quinolone Resistance and Aminoglycoside Resistance Determinants among Carbapeneme Non-Susceptible Enterobacter cloacae. PLoS ONE 7(10): e47636. doi:10.1371/journal.pone.0047636
Editor: Stefan Bereswill, Charit?-University Medicine Berlin, Germany
Received: May 24, 2012; Accepted: September 14, 2012; Published: October 23, 2012
Copyright: ? Huang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported in part by the National Science Foundation of China (Grant No. 81071621 and No.30973378; http://www.nsfc.gov.cn/Portal0/default152.htm). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: liuzhangcq@yahoo.com
# These authors contributed equally to this work.
-Shifeng Huang<SUP>#</SUP>, Wei Dai<SUP>#</SUP>, Shan Sun, Xiaojiao Zhang, Liping Zhang<SUP>*</SUP>
<SUP></SUP>
Department of Laboratory Medicine, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
Abstract
Background
Simultaneous resistance to aminoglycosides and fluoroquinolones in carbapeneme non-susceptible (CNS) isolates will inevitably create problems. The present study was performed to characterize the prevalence of the plasmid-mediated quinolone resistance determinants (QRDs) and aminoglycoside resistance determinants (ARDs) among the CNS Enterobacter cloacae (E. cloacae) isolates in a Chinese teaching hospital, and to acquire their molecular epidemiological characteristics.
Methods
The β-lactamases genes (including class A carbapenemase genes bla<SUB>KPC</SUB> and bla<SUB>SME</SUB>, metallo-β-lactamase genes (MBLs) bla<SUB>IMP</SUB>, bla<SUB>VIM</SUB> and bla<SUB>NDM</SUB>, and extended spectrum β-lactamases (ESBLs),bla<SUB>CTX-M</SUB>, bla<SUB>TEM</SUB> and bla<SUB>SHV</SUB>), QRDs (including qnrA, qnrB, qnrS and aac(6′)-Ib-cr) and ARDs (including aac(6′)-Ib, armA and rmtB) of these 35 isolates were determined by PCR and sequenced bidirectionally. The clonal relatedness was investigated by pulsed-field gel electrophoresis (PFGE).
Results
Of the 35 isolates, 9 (25.7%) harbored a carbapenemase gene; 23 (65.7%) carried ESBLs; 24 (68.6%) were QRD positive; and 27 (77.1%) were ARD positive. Among the 5 bla<SUB>IMP-8</SUB> positive strains, 4 (80%) contained both ESBL and QRD genes, and all the 5 (100%) harbored ARD genes. Of the 23 ESBLs positive isolates, 6 (26.1%) were carbapenemase positive, 14 (60.9%) were QRD positive, and 18 (78.3%) were ARD positive. PFGE revealed genetic diversity among the 35 isolates, indicating that the high prevalence of CNS E. cloacae isolates was not caused by clonal dissemination.
Conclusion
QRD and ARD genes were highly prevalent among the CNS E. cloacae isolates. Multiple resistant genes were co-expressed in the same isolates. The CNS E. cloacae isolate co-expressing bla<SUB>NDM-1</SUB>, bla<SUB>IMP-26</SUB>, qnrA1 and qnrS1 was first reported.
Citation: Huang S, Dai W, Sun S, Zhang X, Zhang L (2012) Prevalence of Plasmid-Mediated Quinolone Resistance and Aminoglycoside Resistance Determinants among Carbapeneme Non-Susceptible Enterobacter cloacae. PLoS ONE 7(10): e47636. doi:10.1371/journal.pone.0047636
Editor: Stefan Bereswill, Charit?-University Medicine Berlin, Germany
Received: May 24, 2012; Accepted: September 14, 2012; Published: October 23, 2012
Copyright: ? Huang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported in part by the National Science Foundation of China (Grant No. 81071621 and No.30973378; http://www.nsfc.gov.cn/Portal0/default152.htm). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: liuzhangcq@yahoo.com
# These authors contributed equally to this work.
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