title: Comparison of Phenotypic Tests and an Immunochromatographic Assay and Development of a New Algorithm for Detection of OXA-48-like Carbapenemases.
abstract: OXA-48 is the most prevalent carbapenemase inEnterobacteriaceaein Europe and the Middle East, but it is frequently missed because many isolates display low MICs for carbapenems. Furthermore, in contrast to metallo-β-lactamases orKlebsiella pneumoniaecarbapenemases (KPC), no specific inhibitor is available for the phenotypic detection of OXA-48. Molecular detection ofblaOXA-48is the "gold standard" but is not available in many laboratories. A few phenotypic assays have been described but have not been independently evaluated. The aim of this study was the systematic comparison of phenotypic tests and an immunochromatographic assay (ICT) for the detection of OXA-48/OXA-48-like carbapenemases and the development of an algorithm for reliable phenotypic detection of OXA-48. Four phenotypic tests (temocillin disk test, faropenem disk test, OXA-48 disk test, and high-inoculum [HI] OXA-48 disk test) and a new ICT (OXA-48K-SeT) were compared by using a set of 166Enterobacteriaceaeisolates, including isolates producing OXA-48/OXA-48-like carbapenemases (n =84) or Ambler class A and B carbapenemases (n =41) and carbapenemase-negative isolates (n =41). The sensitivity and specificity for the different assays were 100% and 43.9% for temocillin, 57.1% and 98.8% for faropenem, 53.6% and 100% for the OXA-48 disk test, 98.8% and 97.6% for the HI OXA-48 disk test, and 100% and 100% for the ICT, respectively. The ICT displayed the highest sensitivity and specificity and was the most rapid assay, but it is more costly than phenotypic assays. Based on these results, a new algorithm incorporating temocillin, faropenem, and ICT which allows cost-effective detection of OXA-48 with 100% sensitivity and specificity was developed.
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Cologne, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Koroska
authors.affiliation: Institute of Medical Microbiology and Infection Control, Hospital of Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Göttig
authors.affiliation: Department of Medical Microbiology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kaase
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Steinmann
authors.affiliation: Department of Medical Microbiology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Gatermann
authors.affiliation: Institute of Medical Microbiology and Infection Control, Hospital of Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Sommer
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Cologne, Germany.|DZIF (German Centre for Infection Research), Bonn-Cologne Partner Site, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Wille
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Cologne, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Plum
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Cologne, Germany axel.hamprecht@uk-koeln.de.|DZIF (German Centre for Infection Research), Bonn-Cologne Partner Site, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Hamprecht
mesh_terms: D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis*; D002846:Chromatography, Affinity / Q000379:methods*; D052978:Disk Diffusion Antimicrobial Tests / Q000379:methods*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D005060:Europe; D006801:Humans; D008877:Middle East; D012680:Sensitivity and Specificity; D001618:beta-Lactamases / Q000032:analysis*; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D047090:beta-Lactams; D001618:beta-Lactamases; C063912:carbapenemase
keywords: OXA-48; OXA-48 K-SeT; carbapenemase; faropenem; temocillin