Back to Journals » Infection and Drug Resistance » Volume 13

High Expression of Metallo-β-Lactamase Contributed to the Resistance to Carbapenem in Clinical Isolates of Pseudomonas aeruginosa from Baotou, China

Authors Xu Y, Niu H, Hu T, Zhang L, Su S, He H, Wang H, Zhang D

Received 9 October 2019

Accepted for publication 17 December 2019

Published 6 January 2020 Volume 2020:13 Pages 35—43

DOI https://doi.org/10.2147/IDR.S233987

Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Sahil Khanna


Yanfeng Xu,1,* Haiying Niu,1,* Tongping Hu,2 Lixia Zhang,2 Shanna Su,1 Huijie He,1 Huimin Wang,1 Dong Zhang1

1Department of Pulmonary Medicine, The First Affiliated Hospital of Baotou Medical College, Baotou, People’s Republic of China; 2Department of Clinical Laboratory, The First Affiliated Hospital of Baotou Medical College, Baotou, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Dong Zhang
Department of Pulmonary Medicine, The First Affiliated Hospital of Baotou Medical College, Baotou, People’s Republic of China
Email zhangdonggh@163.com

Background: Bacterial resistance to antibiotics has become a major public health concern. This study aimed to determine the resistance mechanisms to carbapenem in clinical isolates of Pseudomonas aeruginosa.
Methods: A total of 62 clinical isolates of carbapenem-resistant P. aeruginosa (CRPA) were collected from 2015 to 2017. Imipenem (IPM)–EDTA disk synergy test was used to screen strains that produced metallo-β-lactamase. In addition, the genes for outer membrane protein OprD2, metallo-β-lactamase and mexR gene were amplified and sequenced. Expression of mexA was detected by real-time PCR.
Results: Disk synergy test showed that 51.6% (32/62) of the strains were positive for metallo-β-lactamase. PCR showed that 84.4% of the strains were SIM-positive (27/32), 15.6% of the strains were IMP-positive (5/32), and 12.5% of the strains were VIM-positive (4/32). SPM-positive and GIM-positive strains were not detected. In addition, 5 of the 62 strains had small deletions and/or point mutations in OprD2. Three strains had a high expression of mexA, while eight strains were positive for the regulatory gene mexR with no mutations detected by DNA sequencing.
Conclusion: Expression of metallo-β-lactamase is the main resistance mechanism of P. aeruginosa to carbapenem. Mutations in OprD2 and/or the overexpression of efflux pump MexAB-OprM may contribute to P. aeruginosa resistance to carbapenem.

Keywords: Pseudomonas aeruginosa, carbapenem, metallo-β-lactamase, outer membrane protein OprD2, efflux pump MexAB-OprM

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]