title: Evaluation of the RAPIDEC® CARBA NP, the Rapid CARB Screen® and the Carba NP test for biochemical detection of carbapenemase-producing Enterobacteriaceae.
abstract: OBJECTIVE
  The objective of this study was the evaluation of the performance of two commercially available biochemical tests for the rapid detection of carbapenemase-producing Enterobacteriaceae compared with a home-made technique.
  
  
  METHODS
  A collection of 150 enterobacterial isolates, including 132 isolates with decreased susceptibility to at least one carbapenem molecule, were tested for carbapenemase activity using the RAPIDEC(®) CARBA NP (bioMérieux), the Rapid CARB Screen(®) (Rosco Diagnostica) and the home-made Carba NP test. This strain collection included 55 non-carbapenemase producers, 21 KPC producers, 21 NDM producers, 17 VIM producers, 11 IMP producers, 16 OXA-48 producers and 9 OXA-48-like producers (OXA-162, OXA-181, OXA-204, OXA-232 and OXA-244).
  
  
  RESULTS
  The RAPIDEC(®) CARBA NP detected all carbapenemase producers except a single OXA-244 producer. Using the Rapid CARB Screen(®), one KPC-2, two NDM-1, one OXA-48 and five OXA-48 variant producers gave equivocal results and one OXA-244 producer was not detected. Using the Carba NP test, the same OXA-244 producer was not detected and one OXA-181 producer and one OXA-244 producer gave equivocal results. Sensitivity and specificity were 99% (95% CI 94.3%-99.8%) and 100% (95% CI 93.5%-100%), respectively, for the RAPIDEC(®) CARBA NP test, 89.5% (95% CI 81.7%-94.2%) and 70.9% (95% CI 57.9%-81.2%) for the Rapid CARB Screen(®) and 96.8% (95% CI 91.1%-98.9%) and 100% (95% CI 93.5%-100%) for the Carba NP test. The impact of the use of an adequate bacterial inoculum for obtaining the optimal performance with the RAPIDEC(®) CARBA NP was noted.
  
  
  CONCLUSIONS
  The RAPIDEC(®) CARBA NP possesses the best performance for rapid and efficient detection of carbapenemase-producing Enterobacteriaceae.
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Faculty of Medicine, University of Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Dortet
authors.affiliation: Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Faculty of Medicine, University of Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Agathine
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Faculty of Medicine, University of Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Naas
authors.affiliation: Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Faculty of Medicine, University of Paris-Sud, Le Kremlin-Bicêtre, France Department of Bacteriology-Parasitology-Hygiene, Hôpital de Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Cuzon
authors.affiliation: Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.affiliation: Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland Hôpital Fribourgeois-Hôpital Cantonal, Fribourg, Switzerland patrice.nordmann@unifr.ch.
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D001431:Bacteriological Techniques / Q000379:methods*; D004755:Enterobacteriaceae / Q000201:enzymology*; D004756:Enterobacteriaceae Infections / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013997:Time Factors; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D011933:Reagent Kits, Diagnostic; D001618:beta-Lactamases; C063912:carbapenemase