title: In VitroActivity of Imipenem against Carbapenemase-Positive Enterobacteriaceae Isolates Collected by the SMART Global Surveillance Program from 2008 to 2014.
abstract: The Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program collected 103,960 isolates ofEnterobacteriaceaefrom 2008 to 2014. From this isolate collection, all ertapenem-nonsusceptible isolates (MIC, ≥1 μg/ml;n= 3,428) and 9,371 isolates ofEscherichia coli,Klebsiella pneumoniae,Klebsiella oxytoca, andProteus mirabiliswith an ertapenem-susceptible extended-spectrum-β-lactamase (ESBL)-positive phenotype were assessed for the presence of common carbapenemase genes using a Check-MDR CT101 microarray (Check-Points, Wageningen, the Netherlands) and published multiplex PCR assays. Testing identified 1,493 isolates that harbored a carbapenemase gene (1,485 ertapenem-nonsusceptible isolates and 8 ertapenem-susceptible ESBL-positive isolates) and accounted for 1.4% (1,493/103,960) of all isolates ofEnterobacteriaceaeThe most frequently identified carbapenemase genes were the KPC (n= 794), OXA-48-like (n= 300), and NDM (n= 290) genes. Carbapenemase genes were most frequently identified inKlebsiella pneumoniae(n= 1,127),Escherichia coli(n= 149), andEnterobacter cloacae(n= 110). Among the carbapenemase-positive isolates, 66.7% (2/3), 37.0% (111/300), 20.0% (8/40), 3.3% (3/92), 2.3% (18/794), and 0% (0/290) of the isolates with genes for GES, OXA-48-like, IMP, VIM, KPC, and NDM, respectively, were susceptible to imipenem (MIC, ≤1 μg/ml). Isolates that tested as susceptible to imipenem were not uncommon among carbapenemase-positive isolates (9.4%, 141/1,493) and most frequently carried OXA-48-like enzymes (78.7%; 111/141); however, overall, these isolates remained rare (0.1%, 141/103,960). The practice of screening clinical isolates ofEnterobacteriaceaethat test as susceptible to carbapenemsin vitrofor the presence of carbapenemase genes remains controversial and requires further study.
authors.affiliation: Department of Medical Microbiology, College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: James A
authors.initials: JA
authors.lastname: Karlowsky
authors.affiliation: International Health Management Associates, Inc., Schaumburg, Illinois, USA shlob@ihmainc.com.
authors.forename: Sibylle H
authors.initials: SH
authors.lastname: Lob
authors.affiliation: International Health Management Associates, Inc., Schaumburg, Illinois, USA.
authors.forename: Krystyna M
authors.initials: KM
authors.lastname: Kazmierczak
authors.affiliation: International Health Management Associates, Inc., Schaumburg, Illinois, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Badal
authors.affiliation: Merck Sharp & Dohme Corp., Kenilworth, New Jersey, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Young
authors.affiliation: Merck Sharp & Dohme Corp., Kenilworth, New Jersey, USA.
authors.forename: Mary R
authors.initials: MR
authors.lastname: Motyl
authors.affiliation: International Health Management Associates, Inc., Schaumburg, Illinois, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Sahm
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D000073182:Carbapenem-Resistant Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015378:Imipenem; D001618:beta-Lactamases; C063912:carbapenemase
keywords: SMART; carbapenemase; global; imipenem; surveillance