Evaluation of the RAPIDEC® CARBA NP, the Rapid CARB Screen® and the Carba NP Test for Biochemical Detection of Carbapenemase-Producing Enterobacteriaceae

J Antimicrob Chemother. 2015 Nov;70(11):3014-22. doi: 10.1093/jac/dkv213. Epub 2015 Aug 9.


Objectives: 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.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / analysis*
  • Bacteriological Techniques / methods*
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae Infections / diagnosis*
  • Enterobacteriaceae Infections / microbiology
  • Humans
  • Reagent Kits, Diagnostic*
  • Sensitivity and Specificity
  • Time Factors
  • beta-Lactamases / analysis*


  • Bacterial Proteins
  • Reagent Kits, Diagnostic
  • beta-Lactamases
  • carbapenemase