Evaluation of brilliance CRE agar for the detection of carbapenem-resistant gram-negative bacteria

New Microbiol. 2013 Apr;36(2):181-6. Epub 2013 Mar 31.

Abstract

The aim of this work was to evaluate the performance of the new chromogenic medium BrillianceTM CREAgar (Thermo Fisher Scientific) for determining the limit of detection of carbapenem-resistant enterobacteria (CRE). A total of 70 clinical isolates were studied. Of these, 30 were well-characterized CRE, including Klebsiella pneumoniae strains producing KPC-, VIM-, and OXA-type enzymes, VIM-positive Enterobacter cloacae and Escherichia coli, NDM-positive E. coli, and enterobacterial isolates characterized by porin loss associated with ESBL production or AmpC hyperproduction. Ten carbapenem-resistant non-fermentative isolates were also included as well as 30 carbapenem-susceptible isolates. Carbapenem-resistant strains were inoculated at three different concentrations onto Brilliance CRE Agar (from 1.5x101 CFU/ml up to 1.5x104 CFU/ml) whereas carbapenem-susceptible isolates were inoculated at a concentration of 1.5x102 CFU/ml. The medium sustained the growth of carbapenem-resistant isolates, showing detection limits from 1.5x101 CFU/ml (in 31/40 cases) to 1.5x104 CFU/ml. No growth was observed with carbapenem-sensitive control strains. Our results indicate that the Brilliance CRE Agar allows the growth of carbapenem-resistant isolates with low detection limits and could represent a useful screening medium for both enterobacteria and non-fermentative Gram-negative strains resistant to carbapenems.

Publication types

  • Evaluation Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Carbapenems / pharmacology*
  • Colony Count, Microbial / instrumentation
  • Colony Count, Microbial / methods*
  • Gram-Negative Bacteria / drug effects
  • Gram-Negative Bacteria / growth & development*
  • Gram-Negative Bacteria / isolation & purification*
  • Gram-Negative Bacterial Infections / diagnosis
  • Gram-Negative Bacterial Infections / microbiology*
  • Humans
  • Microbial Sensitivity Tests

Substances

  • Anti-Bacterial Agents
  • Carbapenems