title: Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes.
abstract: Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented.
authors.affiliation: Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland laurent.poirel@unifr.ch.|French INSERM European Unit, University of Fribourg (LEA-IAME), Fribourg, Switzerland.|National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.affiliation: Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland.|French INSERM European Unit, University of Fribourg (LEA-IAME), Fribourg, Switzerland.|National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Jayol
authors.affiliation: Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland.|French INSERM European Unit, University of Fribourg (LEA-IAME), Fribourg, Switzerland.|National Reference Center for Emerging Antibiotic Resistance, Fribourg, Switzerland.|University of Lausanne and University Hospital Center, Lausanne, Switzerland.
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D002875:Chromosomes / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000235:genetics; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy; D006801:Humans; D010957:Plasmids / Q000235:genetics; D011113:Polymyxins / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D011113:Polymyxins
keywords: Gram-negative bacteria; MCR-1; lipopolysaccharide; polymyxins; toxicity