The carbapenem inactivation method (CIM), a simple and low-cost alternative for the Carba NP test to assess phenotypic carbapenemase activity in gram-negative rods

PLoS One. 2015 Mar 23;10(3):e0123690. doi: 10.1371/journal.pone.0123690. eCollection 2015.


A new phenotypic test, called the Carbapenem Inactivation Method (CIM), was developed to detect carbapenemase activity in Gram-negative rods within eight hours. This method showed high concordance with results obtained by PCR to detect genes coding for the carbapenemases KPC, NDM, OXA-48, VIM, IMP and OXA-23. It allows reliable detection of carbapenemase activity encoded by various genes in species of Enterobacteriaceae (e.g., Klebsiella pneumoniae, Escherichia coli and Enterobacter cloacae), but also in non-fermenters Pseudomonas aeruginosa and Acinetobacter baumannii. The CIM was shown to be a cost-effective and highly robust phenotypic screening method that can reliably detect carbapenemase activity.

MeSH terms

  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / genetics
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / antagonists & inhibitors
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Carbapenems / pharmacology
  • DNA, Bacterial / analysis
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / enzymology
  • Enterobacteriaceae / genetics
  • Gram-Negative Bacteria / drug effects
  • Gram-Negative Bacteria / enzymology*
  • Gram-Negative Bacteria / genetics
  • High-Throughput Nucleotide Sequencing
  • Phenotype
  • Polymerase Chain Reaction
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology
  • Pseudomonas aeruginosa / genetics
  • Sequence Analysis, DNA
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carbapenems
  • DNA, Bacterial
  • beta-Lactamases
  • carbapenemase

Grant support

The authors have no support or funding to report.