Rapid Detection of ERG11-Associated Azole Resistance and FKS-Associated Echinocandin Resistance in Candida auris

Antimicrob Agents Chemother. 2018 Dec 21;63(1):e01811-18. doi: 10.1128/AAC.01811-18. Print 2019 Jan.

Abstract

Candida auris is an emerging multidrug-resistant yeast that can cause serious invasive infections. The accurate and rapid assessment of antifungal resistance is important for effective patient management. A novel and highly accurate diagnostic platform was established for the rapid identification of ERG11 mutations conferring azole resistance and FKS1 mutations associated with echinocandin resistance in C. auris Using allele-specific molecular beacons and DNA melting curve analysis following asymmetric PCR, a duplex ERG11 assay and a simplex FKS1 HS1 assay were developed to identify the most prominent resistance-associated mutations (Y132F and K143R in ERG11; S639F in FKS1 HS1) within 2 h. Assays were validated by testing a panel of 94 C. auris clinical isolates in a blind manner. The molecular diagnostic results from the assays were 100% concordant with DNA sequencing results. This platform has the potential to overcome the deficiencies of existing in vitro susceptibility-based assays to identify azole- and/or echinocandin-resistant C. auris, and thus, it holds promise as a surrogate diagnostic method to direct antifungal therapy more effectively.

Keywords: Candida auris; ERG11; FKS; azole; echinocandin; molecular beacons; resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Anidulafungin / pharmacology
  • Antifungal Agents / pharmacology*
  • Candida / drug effects
  • Candida / enzymology
  • Candida / genetics*
  • Candida / isolation & purification
  • Candidiasis / drug therapy
  • Candidiasis / microbiology
  • Caspofungin / pharmacology
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • DNA Mutational Analysis
  • Drug Resistance, Fungal / genetics*
  • Fluconazole / pharmacology
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression
  • Glucosyltransferases / genetics*
  • Glucosyltransferases / metabolism
  • Humans
  • Micafungin / pharmacology
  • Mutation
  • Nucleic Acid Denaturation
  • Polymerase Chain Reaction / methods*
  • Voriconazole / pharmacology

Substances

  • Antifungal Agents
  • Fungal Proteins
  • Fluconazole
  • Cytochrome P-450 Enzyme System
  • Anidulafungin
  • Glucosyltransferases
  • Caspofungin
  • Voriconazole
  • Micafungin