Identification of Novel Mobile Colistin Resistance Gene mcr-10

Emerg Microbes Infect. 2020 Mar 2;9(1):508-516. doi: 10.1080/22221751.2020.1732231. eCollection 2020.

Abstract

Mobile colistin resistance (mcr) genes represent an emerging challenge. Here we describe a novel mcr gene, mcr-10, on an IncFIA plasmid of an Enterobacter roggenkampii clinical strain. mcr-10 has the highest nucleotide identity (79.69%) with mcr-9 and encodes MCR-10 with 82.93% amino acids identical to MCR-9. mcr-10 confers 4-fold increase in colistin MIC (from 1 to 4 mg/L) when cloned into a colistin-susceptible E. roggenkampii strain. By screening GenBank, mcr-10 was found in various Enterobacteriaceae species of countries in four continents, suggesting that this gene has widely spread. MCR-10 shows 79.04% to 83.67% amino acid identity and highly conserved predicted protein structures with chromosomally encoded MCR-like phosphoethanolamine transferases (designated MCR-B here) of various Buttiauxella species. MCR-10, MCR-9 and MCR-B proteins may, therefore, originate from a common ancestor. mcr-10 was adjacent to a site-specific recombinase-encoding gene and was bracketed by IS903 and may be mobilized by site-specific recombination or composite transposon. Our results indicate that mcr-10 is a novel plasmid-borne colistin resistance gene and warrants immediate monitoring and further studies.

Keywords: Colistin resistance; Enterobacter roggenkampii; mcr; mcr-10; plasmid.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Colistin / pharmacology
  • Databases, Genetic
  • Drug Resistance, Bacterial
  • Enterobacteriaceae / chemistry
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / genetics*
  • Models, Molecular
  • Plasmids
  • Protein Structure, Tertiary
  • Sequence Analysis, Protein

Substances

  • Bacterial Proteins
  • Colistin

Grant support

This work was supported by grants from the National Natural Science Foundation of China [project no. 81772233, 81661130159 and 81861138055], West China Hospital of Sichuan University [1.3.5 project for disciplines of excellence, project no. ZYYC08006], the Newton Advanced Fellowship, Royal Society, UK [NA150363]. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.