title: Evaluation of two new commercial immunochromatographic assays for the rapid detection of OXA-48 and KPC carbapenemases from cultured bacteria.
abstract: BACKGROUND
  Rapid detection and confirmation of carbapenemases remains very challenging for diagnostic laboratories.
  
  
  OBJECTIVE
  The objective of this study was to assess the performance of two new immunochromatographic (IC) commercial assays for the rapid detection of OXA-48-producing and KPC-producing Enterobacteriaceae in pure bacterial isolates.
  
  
  METHODS
  A panel of 92 bacterial isolates predominantly including carbapenem-non-susceptible Enterobacteriaceae with previously defined carbapenem resistance mechanisms was tested. Then, 342 consecutive carbapenem-non-susceptible Enterobacteriaceae isolates referred to the reference laboratory were investigated prospectively in parallel with other phenotypic tests and with multiplex PCR and sequencing as the gold standard.
  
  
  RESULTS
  In the collection panel, each of the two IC assays correctly detected all 30 OXA-48-like-producing isolates and 25 KPC-producing isolates, whatever the species, their association with other β-lactamases and the level of resistance to carbapenems. All other carbapenemase producers and all non-carbapenemase-producing isolates yielded negative results with both tests. In the prospective evaluation, all OXA-48-like-producing Enterobacteriaceae isolates (n = 130) and KPC-producing Enterobacteriaceae isolates (n = 33) were correctly detected by the individual IC assays, while 179 non-OXA-48-like-producing and non-KPC-producing strains (137 non-carbapenemase producers and 42 isolates belonging to other carbapenemase family types) yielded negative results. Thus, each assay yielded 100% sensitivity and 100% specificity for the detection of OXA-48-like or KPC enzymes, respectively, at 15 min.
  
  
  CONCLUSIONS
  The two IC assays allow rapid and reliable direct confirmation of OXA-48 and KPC carbapenemases from culture colonies and appear to be very useful additions to the existing tests, obviating the need for more costly characterization by molecular amplification methods.
authors.affiliation: National Reference Laboratory for Monitoring of Antimicrobial Resistance in Gram-Negative Bacteria, CHU Dinant-Godinne, UCL Namur, B-5530 Yvoir, Belgium gerald.glupczynski@uclouvain.be.
authors.forename: Youri
authors.initials: Y
authors.lastname: Glupczynski
authors.affiliation: National Reference Laboratory for Monitoring of Antimicrobial Resistance in Gram-Negative Bacteria, CHU Dinant-Godinne, UCL Namur, B-5530 Yvoir, Belgium.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Evrard
authors.affiliation: Coris BioConcept, Crealys Park, B-5032 Gembloux, Belgium.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ote
authors.affiliation: Coris BioConcept, Crealys Park, B-5032 Gembloux, Belgium.
authors.forename: Pascal
authors.initials: P
authors.lastname: Mertens
authors.affiliation: National Reference Laboratory for Monitoring of Antimicrobial Resistance in Gram-Negative Bacteria, CHU Dinant-Godinne, UCL Namur, B-5530 Yvoir, Belgium.
authors.forename: Te-Din
authors.initials: TD
authors.lastname: Huang
authors.affiliation: Coris BioConcept, Crealys Park, B-5032 Gembloux, Belgium.
authors.forename: Thierry
authors.initials: T
authors.lastname: Leclipteux
authors.affiliation: National Reference Laboratory for Monitoring of Antimicrobial Resistance in Gram-Negative Bacteria, CHU Dinant-Godinne, UCL Namur, B-5530 Yvoir, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bogaerts
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D001431:Bacteriological Techniques / Q000379:methods*; D002846:Chromatography, Affinity / Q000379:methods*; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D006801:Humans; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D013997:Time Factors; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase