title: Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.
abstract: Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided.
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm, Sweden. anna-pelagia.magiorakos@ecdc.europa.eu
authors.forename: A-P
authors.initials: AP
authors.lastname: Magiorakos
authors.forename: A
authors.initials: A
authors.lastname: Srinivasan
authors.forename: R B
authors.initials: RB
authors.lastname: Carey
authors.forename: Y
authors.initials: Y
authors.lastname: Carmeli
authors.forename: M E
authors.initials: ME
authors.lastname: Falagas
authors.forename: C G
authors.initials: CG
authors.lastname: Giske
authors.forename: S
authors.initials: S
authors.lastname: Harbarth
authors.forename: J F
authors.initials: JF
authors.lastname: Hindler
authors.forename: G
authors.initials: G
authors.lastname: Kahlmeter
authors.forename: B
authors.initials: B
authors.lastname: Olsson-Liljequist
authors.forename: D L
authors.initials: DL
authors.lastname: Paterson
authors.forename: L B
authors.initials: LB
authors.lastname: Rice
authors.forename: J
authors.initials: J
authors.lastname: Stelling
authors.forename: M J
authors.initials: MJ
authors.lastname: Struelens
authors.forename: A
authors.initials: A
authors.lastname: Vatopoulos
authors.forename: J T
authors.initials: JT
authors.lastname: Weber
authors.forename: D L
authors.initials: DL
authors.lastname: Monnet
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001424:Bacterial Infections / Q000382:microbiology*; D003428:Cross Infection / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D005060:Europe; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000592:standards; D009626:Terminology as Topic
chemical_list: D000900:Anti-Bacterial Agents