The A395T mutation in ERG11 gene confers fluconazole resistance in Candida tropicalis causing candidemia

Mycopathologia. 2015 Apr;179(3-4):213-8. doi: 10.1007/s11046-014-9831-8. Epub 2014 Nov 15.

Abstract

The mechanism of fluconazole resistance in Candida tropicalis is still unclear. Recently, we isolated a fluconazole-resistant strain of C. tropicalis from the blood specimen of a patient with candidemia in China. In vitro antifungal susceptibility of the isolate was determined by using CLSI M27-A3 and E-test methods. The sequence of ERG11 gene was then analyzed, and the three-dimensional model of Erg11p encoded by ERG11 gene was also investigated. The sequencing of ERG11 gene revealed the mutation of A395T in this fluconazole-resistant isolate of C. tropicalis, resulting in the Y132F substitution in Erg11p. Sequence alignment and three-dimensional model comparison of Erg11ps showed high similarity between fluconazole-susceptible isolates of C. tropicalis and Candida albicans. The comparison of the three-dimensional models of Erg11ps demonstrated that the position of the Y132F substitution in this isolate of C. tropicalis is identical to the isolate of C. albicans with fluconazole resistance resulting from Y132F substitution in Erg11p. Hence, we ascertain that the Y132F substitution of Erg11p caused by A395T mutation in ERG11 gene confers the fluconazole resistance in C. tropicalis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antifungal Agents / pharmacology*
  • Candida tropicalis / drug effects*
  • Candida tropicalis / enzymology
  • Candida tropicalis / genetics*
  • Candidemia / drug therapy
  • Candidemia / microbiology*
  • Candidiasis / drug therapy
  • Candidiasis / microbiology*
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • Fluconazole / pharmacology*
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Humans
  • Mutation, Missense* / drug effects

Substances

  • Antifungal Agents
  • Fungal Proteins
  • Fluconazole
  • Cytochrome P-450 Enzyme System