mcr-3 and mcr-4 Variants in Carbapenemase-Producing Clinical Enterobacteriaceae Do Not Confer Phenotypic Polymyxin Resistance
Teo, Jeanette W. P.
Ng, Oon Tek
Lin, Raymond T. P.
Date of Issue2018
Lee Kong Chian School of Medicine
The worldwide distribution of plasmid-mediated colistin resistance determinants (mcr-1, mcr-2, mcr-3, and mcr-4) coupled to the emerging observation that colistin resistance is more prevalent in carbapenem-resistant Enterobacteriaceae (CRE) (1, 2) presents a daunting challenge in combatting antimicrobial resistance. Undoubtedly, next-generation sequencing approaches have expedited the discovery of mobile colistin resistance determinants (3). In this study, we undertook the in silico screening of 500 phenotypically carbapenem-resistant carbapenemase-producing Enterobacteriaceae whole genomes for the presence of the mcr gene, using CLC Genomics Workbench (CLC Bio-Qiagen, Aarhus, Denmark). The isolates comprised clinical and screening pure cultures submitted to the national reference laboratory for mandatory CRE surveillance. Locally, the presence of mcr-1 as well as its cocarriage with KPC-2 had been previously well described (4, 5); hence, we did not look further into the distribution of mcr-1. mcr-2 was not detected among the genomes analyzed. mcr-3 was identified in one Escherichia coli genome (ENT1955) by the use of both read mapping and de novo assembly.
Journal of Clinical Microbiology
© 2018 American Society for Microbiology. This paper was published in Journal of Clinical Microbiology and is made available as an electronic reprint (preprint) with permission of American Society for Microbiology. The published version is available at: [http://dx.doi.org/10.1128/JCM.01562-17]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.