title: Susceptibility of Klebsiella pneumoniae isolates from intra-abdominal infections and molecular characterization of ertapenem-resistant isolates.
abstract: A total of 2,841 clinical isolates of Klebsiella pneumoniae from intra-abdominal infections worldwide were collected in the Study for Monitoring Antimicrobial Resistance Trends (SMART) during 2008 and 2009. Overall, 22.4% of isolates had extended-spectrum β-lactamases (ESBLs). The most active antibiotics among the 11 tested were imipenem, amikacin, and ertapenem, though even these, like all other comparators, were less consistently active against ESBL-positive isolates than against ESBL-negative isolates. Globally, 6.5% of isolates were ertapenem resistant based on the June 2010 clinical breakpoints published by the Clinical and Laboratory Standards Institute, with MICs of ≥1 μg/ml. Molecular characterization of 43 isolates with ertapenem MICs of ≥4 μg/ml showed that they variously produced CTX-M or SHV ESBLs combined with altered impermeability and/or had KPC (n = 28), OXA-48 (n = 3), or VIM (n = 1) carbapenemases. Further monitoring of ertapenem susceptibility and molecular characterization of ertapenem-resistant isolates are needed.
authors.affiliation: IHMA Europe Sàrl, 1066 Epalinges, Switzerland. shawser@ihmainc.com
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Hawser
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Bouchillon
authors.forename: Christine
authors.initials: C
authors.lastname: Lascols
authors.forename: Meredith
authors.initials: M
authors.lastname: Hackel
authors.forename: Daryl J
authors.initials: DJ
authors.lastname: Hoban
authors.forename: Robert E
authors.initials: RE
authors.lastname: Badal
authors.forename: Neil
authors.initials: N
authors.lastname: Woodford
authors.forename: David M
authors.initials: DM
authors.lastname: Livermore
mesh_terms: D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis; D024901:Drug Resistance, Multiple, Bacterial; D000077727:Ertapenem; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D059413:Intraabdominal Infections / Q000382:microbiology*; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000096:biosynthesis*; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D047090:beta-Lactams; D015378:Imipenem; D000583:Amikacin; D001618:beta-Lactamases; C063912:carbapenemase; D000077727:Ertapenem