1. A novel plasmid-encoded mcr-4.3 gene in a colistin-resistant Acinetobacter baumannii clinical strain.
- Author
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Martins-Sorenson N, Snesrud E, Xavier DE, Cacci LC, Iavarone AT, McGann P, Riley LW, and Moreira BM
- Subjects
- Acinetobacter Infections microbiology, Brazil, Genome, Bacterial, Humans, Meningitis, Bacterial microbiology, Microbial Sensitivity Tests, Whole Genome Sequencing, Acinetobacter baumannii drug effects, Acinetobacter baumannii genetics, Anti-Bacterial Agents pharmacology, Bacterial Proteins genetics, Colistin pharmacology, Drug Resistance, Multiple, Bacterial genetics, Plasmids genetics
- Abstract
Objectives: To identify the molecular mechanism of colistin resistance in an MDR Acinetobacter baumannii clinical strain isolated in 2008 from a meningitis case in Brazil., Methods: Long- and short-read WGS was used to identify colistin resistance genes in A. baumannii strain 597A with a colistin MIC of 64 mg/L. MS was used to analyse lipid A content. mcr was cloned into pET-26b (+) and transformed into Escherichia coli BL21(λDE3)pLysS for analysis., Results: A novel plasmid (pAb-MCR4.3) harbouring mcr-4.3 within a Tn3-like transposon was identified. The A. baumannii 597A lipid A MS spectra showed a main molecular ion peak at m/z=2034, which indicated the addition of phosphoethanolamine to the lipid A structure. E. coli BL21 transformed with pET-26b-mcr-4.3 gained colistin resistance with a colistin MIC of 8 mg/L., Conclusions: Colistin resistance in A. baumannii 597A was correlated with the presence of a novel plasmid-encoded mcr-4.3 gene., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
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