Plasmid-mediated quinolone resistance: Two decades on

Drug Resist Updat. 2016 Nov:29:13-29. doi: 10.1016/j.drup.2016.09.001. Epub 2016 Sep 13.

Abstract

After two decades of the discovery of plasmid-mediated quinolone resistance (PMQR), three different mechanisms have been associated to this phenomenon: target protection (Qnr proteins, including several families with multiple alleles), active efflux pumps (mainly QepA and OqxAB pumps) and drug modification [AAC(6')-Ib-cr acetyltransferase]. PMQR genes are usually associated with mobile or transposable elements on plasmids, and, in the case of qnr genes, are often incorporated into sul1-type integrons. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. Although the three PMQR mechanisms alone cause only low-level resistance to quinolones, they can complement other mechanisms of chromosomal resistance to reach clinical resistance level and facilitate the selection of higher-level resistance, raising a threat to the treatment of infections by microorganisms that host these mechanisms.

Keywords: AAC(6′)-Ib-cr; OqxAB; Plasmid; QepA; Qnr; Quinolone; Resistance.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Infections / drug therapy
  • Bacterial Infections / microbiology
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Chromosomes, Bacterial / chemistry
  • Chromosomes, Bacterial / metabolism
  • Drug Resistance, Bacterial / genetics*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial*
  • Gram-Negative Bacteria / drug effects
  • Gram-Negative Bacteria / genetics*
  • Gram-Negative Bacteria / metabolism
  • Gram-Positive Bacteria / drug effects
  • Gram-Positive Bacteria / genetics*
  • Gram-Positive Bacteria / metabolism
  • Humans
  • Microbial Sensitivity Tests
  • Plasmids / chemistry
  • Plasmids / metabolism*
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Quinolones / pharmacology
  • Treatment Failure

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Escherichia coli Proteins
  • Protein Isoforms
  • QepA protein, E coli
  • Qnr protein, Klebsiella pneumoniae
  • Quinolones
  • Acetyltransferases
  • aminoglycoside N(6')-acetyltransferase