In vitro antifungal susceptibilities and amplified fragment length polymorphism genotyping of a worldwide collection of 350 clinical, veterinary, and environmental Cryptococcus gattii isolates

Antimicrob Agents Chemother. 2010 Dec;54(12):5139-45. doi: 10.1128/AAC.00746-10. Epub 2010 Sep 20.

Abstract

The in vitro susceptibilities of a worldwide collection of 350 Cryptococcus gattii isolates to seven antifungal drugs, including the new triazole isavuconazole, were tested. With amplified fragment length polymorphism (AFLP) fingerprinting, human, veterinary, and environmental C. gattii isolates were subdivided into seven AFLP genotypes, including the interspecies hybrids AFLP8 and AFLP9. The majority of clinical isolates (n = 215) comprised genotypes AFLP4 (n = 76) and AFLP6 (n = 103). The clinical AFLP6 isolates had significantly higher geometric mean MICs for flucytosine and fluconazole than the clinical AFLP4 isolates. Of the seven antifungal compounds examined in this study, isavuconazole had the lowest MIC(90) (0.125 μg/ml) for all C. gattii isolates, followed by a 1 log(2) dilution step increase (MIC(90), 0.25 μg/ml) for itraconazole, voriconazole, and posaconazole. Amphotericin B had an acceptable MIC(90) of 0.5 μg/ml, but fluconazole and flucytosine had relatively high MIC(90)s of 8 μg/ml.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphotericin B / pharmacology
  • Amplified Fragment Length Polymorphism Analysis
  • Animals
  • Antifungal Agents / pharmacology*
  • Cryptococcus gattii / drug effects*
  • Cryptococcus gattii / genetics*
  • Cryptococcus gattii / isolation & purification
  • Environmental Microbiology
  • Fluconazole / pharmacology
  • Flucytosine / pharmacology
  • Genotype
  • Humans
  • Microbial Sensitivity Tests
  • Nitriles / pharmacology
  • Pyridines / pharmacology
  • Pyrimidines / pharmacology
  • Triazoles / pharmacology
  • Voriconazole

Substances

  • Antifungal Agents
  • Nitriles
  • Pyridines
  • Pyrimidines
  • Triazoles
  • isavuconazole
  • posaconazole
  • Amphotericin B
  • Fluconazole
  • Flucytosine
  • Voriconazole