Evaluation of the Carba NP test for rapid detection of carbapenemase-producing Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrob Agents Chemother. 2013 Sep;57(9):4578-80. doi: 10.1128/AAC.00878-13. Epub 2013 Jul 1.

Abstract

The Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producing Enterobacteriaceae and Pseudomonas aeruginosa isolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification*
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / isolation & purification
  • Humans
  • Microbial Sensitivity Tests / standards*
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology*
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / isolation & purification
  • Sensitivity and Specificity
  • beta-Lactamases / biosynthesis
  • beta-Lactamases / genetics
  • beta-Lactamases / isolation & purification*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-Lactamases
  • carbapenemase