title: Prospective evaluation of the OXA-48 K-SeT assay, an immunochromatographic test for the rapid detection of OXA-48-type carbapenemases.
abstract: There is an urgent need for accurate and fast diagnostic tests to identify MDR bacteria. Here, we evaluated an immunochromatographic assay (the OXA-48 K-SeT assay) to detect OXA-48-like carbapenemase-producing Enterobacteriaceae from culture colonies.
  
  
  
  One hundred and sixty-one collection isolates with characterized β-lactamase content and 185 non-duplicate consecutive clinical isolates referred to the Associated French National Reference Center between 15 February and 15 March 2015 were used to evaluate the OXA-48 K-SeT assay. Among these 346 isolates, 100 were OXA-48-like carbapenemase producers, 3 were OXA-48-like producers lacking carbapenemase activity and 243 were ESBL, AmpC, oxacillinase and/or non-OXA-48 carbapenemase producers.
  
  
  
  All 100 OXA-48-like carbapenemase producers were correctly detected by the OXA-48 K-SeT assay, including OXA-48 (n = 73), OXA-181 (n = 18), OXA-162 (n = 1), OXA-204 (n = 4), OXA-232 (n = 2) and OXA-244 (n = 2) variants. The three OXA-48 variants lacking carbapenemase activity, OXA-163 (n = 2) and OXA-405 (n = 1), were not detected. All non-OXA-48 producers gave a negative result with the OXA-48 K-SeT assay. No cross-reaction was evidenced with the carbapenemases (VIM, IMP, NDM and KPC), ESBLs (TEM, SHV and CTX-M), AmpCs (CMY-2, DHA-2 and ACC-1) and oxacillinases (OXA-1, -2, -9 and -10). Overall, the sensitivity and specificity of the assay were 100% for OXA-48-like carbapenemase detection.
  
  
  
  The OXA-48 K-SeT assay was efficient, rapid and easy to implement in the routine workflow of a clinical microbiology laboratory for the confirmation of OXA-48-like carbapenemase-producing Enterobacteriaceae. It could complete the existing panel of tests available for the confirmation of OXA-48-like carbapenemases, especially in countries with high OXA-48 prevalence.
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit EA7361 'Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases', Faculty of Medicine, University Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-University Paris Sud, Paris, France laurent.dortet@aphp.fr.
authors.forename: Laurent
authors.initials: L
authors.lastname: Dortet
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit EA7361 'Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases', Faculty of Medicine, University Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-University Paris Sud, Paris, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Jousset
authors.affiliation: Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Sainte-Rose
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit EA7361 'Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases', Faculty of Medicine, University Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-University Paris Sud, Paris, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Cuzon
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit EA7361 'Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases', Faculty of Medicine, University Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France Joint Research Unit EERA 'Evolution and Ecology of Resistance to Antibiotics', Institut Pasteur-APHP-University Paris Sud, Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Naas
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D001431:Bacteriological Techniques / Q000379:methods*; D002846:Chromatography, Affinity / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D006801:Humans; D011446:Prospective Studies; D013997:Time Factors; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase