title: Prospective evaluation of an algorithm for the phenotypic screening of carbapenemase-producing Enterobacteriaceae.
abstract: OBJECTIVE
  The objective of this study was to assess the performance of an algorithm based on the disc diffusion method for the screening of carbapenemase-producing Enterobacteriaceae (CPE) referred to the French National Reference Centre for Antibiotic Resistance.
  
  
  METHODS
  From April to June 2014, all isolates of Enterobacteriaceae referred to the French National Reference Centre for Antibiotic Resistance were included. The inhibition zone diameters of imipenem, ticarcillin/clavulanate and temocillin using EUCAST disc diffusion methodology were recorded. All isolates were subjected to the algorithm proposed by the Antibiogram Committee of the French Society of Microbiology (CA-SFM) for the screening of carbapenemase producers. Phenotypic, biochemical and molecular detection of carbapenemases was performed for all isolates.
  
  
  RESULTS
  A total of 621 consecutive enterobacterial isolates with decreased susceptibility to carbapenems were tested. They included 213 CPE [OXA-48-like (n = 183), NDM (n = 22), VIM (n = 3), KPC (n = 3) and OXA-48-like + NDM (n = 2)] and 408 non-carbapenemase producers. The CA-SFM algorithm combining cut-off values of 15 mm, 15 mm and 22 mm for ticarcillin/clavulanate, temocillin and imipenem, respectively, perfectly detected 204 isolates (32.8%) as non-carbapenemase producers, leading to a negative predictive value of 100% for this algorithm.
  
  
  CONCLUSIONS
  Implementation of the CA-SFM algorithm in clinical microbiology laboratories may avoid additional testing for CPE in one-third of the enterobacterial isolates with decreased susceptibility to carbapenems.
authors.affiliation: Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France French National Reference Centre for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, Le Kremlin-Bicêtre, France EA7361 Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Paris-Sud University, LabEx LERMIT, Faculty of Medicine, Le Kremlin-Bicêtre, France laurent.dortet@bct.aphp.fr.
authors.forename: Laurent
authors.initials: L
authors.lastname: Dortet
authors.affiliation: Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France French National Reference Centre for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, Le Kremlin-Bicêtre, France EA7361 Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Paris-Sud University, LabEx LERMIT, Faculty of Medicine, Le Kremlin-Bicêtre, France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: Cuzon
authors.affiliation: French National Reference Centre for Antibiotic Resistance, University Hospital of Besançon, Besançon, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Plésiat
authors.affiliation: Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France French National Reference Centre for Antibiotic Resistance: Carbapenemase-Producing Enterobacteriaceae, Le Kremlin-Bicêtre, France EA7361 Research Unit 'Structure, dynamic, function and expression of broad spectrum β-lactamases', Paris-Sud University, LabEx LERMIT, Faculty of Medicine, Le Kremlin-Bicêtre, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Naas
mesh_terms: D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D052978:Disk Diffusion Antimicrobial Tests / Q000379:methods*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005602:France; D006801:Humans; D008403:Mass Screening / Q000379:methods* / Q000458:organization & administration; D011446:Prospective Studies; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D047090:beta-Lactams; D001618:beta-Lactamases; C063912:carbapenemase