Comparison of the Etest and microdilution method for antifungal susceptibility testing of Cryptococcus neoformans to four antifungal agents

J Antimicrob Chemother. 2000 Dec;46(6):997-1000. doi: 10.1093/jac/46.6.997.

Abstract

We performed a prospective study to compare the Etest and the microdilution method (NCCLS guidelines) for determining the MICs of fluconazole, itraconazole, flucytosine and amphotericin B for 35 strains of Cryptococcus neoformans. For the microdilution method (MDM) RPMI 1640 medium with 2% glucose was used for fluconazole, itraconazole and flucytosine, and Antibiotic Medium 3 for amphotericin B. For the Etest, RPMI 1640 medium with 2% glucose and solidified with 1.5% agar was used for the four antifungal agents. Amphotericin B was also tested on Antibiotic Medium 3 solidified with 1.5% agar. Fluconazole and flucytosine MICs by the Etest showed good correlation with the broth MDM (81.1 and 89.2% agreement within two dilutions, respectively). With the tested population of itraconazole- and amphotericin B-susceptible isolates, the MIC agreement for itraconazole was 54%; amphotericin B showed the lowest agreement (8.1% on Antibiotic Medium 3 and 13.5% on RPMI).

Publication types

  • Comparative Study

MeSH terms

  • Amphotericin B / pharmacology
  • Antifungal Agents / pharmacology*
  • Cryptococcus neoformans / drug effects*
  • Fluconazole / pharmacology
  • Flucytosine / pharmacology
  • Itraconazole / pharmacology
  • Microbial Sensitivity Tests / methods*
  • Retrospective Studies

Substances

  • Antifungal Agents
  • Itraconazole
  • Amphotericin B
  • Fluconazole
  • Flucytosine