title: Evaluation of five chromogenic agar media and the Rosco Rapid Carb screen kit for detection and confirmation of carbapenemase production in Gram-negative bacilli.
abstract: 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.
authors.affiliation: Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada University of Manitoba, Department of Medical Microbiology and Infectious Diseases, Winnipeg, Manitoba, Canada psimner@dsmanitoba.ca.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Simner
authors.affiliation: Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada University of Manitoba, Department of Medical Microbiology and Infectious Diseases, Winnipeg, Manitoba, Canada.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gilmour
authors.affiliation: Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Pat
authors.initials: P
authors.lastname: DeGagne
authors.affiliation: Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Kim
authors.initials: K
authors.lastname: Nichol
authors.affiliation: Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada University of Manitoba, Department of Medical Microbiology and Infectious Diseases, Winnipeg, Manitoba, Canada.
authors.forename: James A
authors.initials: JA
authors.lastname: Karlowsky
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D003470:Culture Media; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics*; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D060885:Multiplex Polymerase Chain Reaction; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D057188:Workflow; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003470:Culture Media; D011933:Reagent Kits, Diagnostic; D001618:beta-Lactamases; C063912:carbapenemase