A novel plasmid-encoded mcr-4.3 gene in a colistin-resistant Acinetobacter baumannii clinical strain. (3rd October 2019)

• Record Type: Journal Article
• Authors: Martins-Sorenson, Natacha; Snesrud, Erik; Xavier, Danilo Elias; Cacci, Luciana Camila; Iavarone, Anthony T; McGann, Patrick; Riley, Lee W; Moreira, Beatriz Meurer
• Is Part Of: Journal of antimicrobial chemotherapy. Volume 75:Number 1(2020)
• Page Start: 60
• Page End: 64
• Publication Date: 2019-10-03
• Subjects: Anti-infective agents -- Periodicals; Chemotherapy -- Periodicals; 615.58
• DOI: 10.1093/jac/dkz413
• Languages: English
• ISSNs: 0305-7453

Abstract

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 Tn 3 -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.