Evaluation of five chromogenic agar media and the Rosco Rapid Carb screen kit for detection and confirmation of carbapenemase production in Gram-negative bacilli

Patricia J Simner, Matthew W Gilmour, Pat DeGagne, Kim Nichol, James A Karlowsky

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


An efficient workflow to screen for and confirm the presence of carbapenemase-producing Gram-negative bacilli was developed by evaluating five chromogenic screening agar media and two confirmatory assays, the Rapid Carb screen test (Rosco Diagnostica A/S, Taastrup, Denmark) and the modified Hodge test. A panel of 150 isolates was used, including 49 carbapenemase-producing isolates representing a variety of β-lactamase enzyme classes. An evaluation of analytical performance, assay cost, and turnaround time indicated that the preferred workflow (screening test followed by confirmatory testing) was the chromID Carba agar medium (bioMérieux, Marcy l'Étoile, France), followed by the Rapid Carb screen test, yielding a combined sensitivity of 89.8% and a specificity of 100%. As an optional component of the workflow, a determination of carbapenemase gene class via molecular means could be performed subsequent to confirmatory testing.

Original languageEnglish
Pages (from-to)105-112
Number of pages8
JournalJournal of Clinical Microbiology
Issue number1
Early online date18 Dec 2014
Publication statusPublished - Jan 2015


  • Anti-Bacterial Agents/pharmacology
  • Bacterial Proteins/genetics
  • Culture Media
  • Gram-Negative Bacteria/classification
  • Gram-Negative Bacterial Infections/diagnosis
  • Humans
  • Microbial Sensitivity Tests/methods
  • Multiplex Polymerase Chain Reaction
  • Reagent Kits, Diagnostic
  • Reproducibility of Results
  • Workflow
  • beta-Lactamases/genetics

Cite this