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Identification and characterization of a Cryptococcus neoformans ATP binding cassette (ABC) transporter-encoding

Brunella Posteraro1, Maurizio Sanguinetti, Dominique Sanglard

  • 1Istituto Microbiologia, Università Cattolica del S. Cuore, L. go F. Vito, 1, 00168 Rome, Italy.

Molecular Microbiology
|January 10, 2003
PubMed

Insights

Fluconazole resistance in Cryptococcus neoformans can develop through active drug efflux. A key gene, CnAFR1, encodes an ATP Binding Cassette transporter involved in this antifungal resistance mechanism.

Area of Science:

  • Mycology
  • Molecular Biology
  • Antimicrobial Resistance

Background:

  • Cryptococcal meningitis, a severe manifestation of cryptococcosis, can lead to fluconazole resistance during treatment.
  • Understanding the molecular basis of azole resistance is crucial for managing cryptococcosis.

Purpose of the Study:

  • To identify genes contributing to fluconazole resistance in Cryptococcus neoformans.
  • To elucidate the molecular mechanisms underlying antifungal drug resistance.

Main Methods:

  • Generated a fluconazole-resistant mutant (BPY22.17) from a susceptible strain (BPY22).
  • Employed cDNA subtraction library and subtractive hybridization to compare gene expression.
  • Isolated and sequenced the overexpressed gene, identified as CnAFR1 (ATP Binding Cassette transporter).
  • Performed gene disruption and reintroduction experiments to confirm CnAFR1's role.

Main Results:

  • Identified a novel ATP Binding Cassette (ABC) transporter gene, CnAFR1, overexpressed in the resistant strain.
  • Disruption of CnAFR1 increased susceptibility to fluconazole, while reintroduction restored resistance.
  • Confirmed CnAFR1's direct involvement in fluconazole resistance.

Conclusions:

  • CnAFR1 plays a significant role in fluconazole resistance in Cryptococcus neoformans.
  • Active drug efflux mediated by ABC transporters is a key mechanism for azole resistance in this pathogen.

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