title: [Characterization of azole resistance mechanisms in Chilean clinical isolates of Candida albicans].
abstract: BACKGROUND
  The commensal yeast Candida albicans, can cause superficial or systemic candidiasis in susceptible hosts. In Chile, azole antifungals are the most widely used drugs in the treatment of candidiasis. In a previous study performed at our center, 2.1 and 1.6% of clinical isolates of C. albicans were found to be resistant to fluconazole and voriconazole, respectively.
  
  
  OBJECTIVE
  To characterize the resistance mechanisms involved in azoles resistance in Chilean clinical isolates.
  
  
  METHODS
  Eight resistant, nine susceptible-dose dependent (SDD) and 10 susceptible strains (n: 27) were selected according to the Clinical Laboratory Standards Institute (CLSI) M27-S3 criteria, from vaginal and urine samples. Mutations in the 408-488 region of the ERG11 gene were studied by sequencing, and the relative expression of ERG11 gene and efflux pump genes CDR1, CDR2 and MDR1, was evaluated by quantitative real-time PCR (q-PCR).
  
  
  RESULTS
  No mutations were detected in the ERG11 gene and its overexpression was found only in 12.5% of the resistant strains (1/8). The most prevalent mechanism of resistance was the over-expression of efflux pumps (62.5%; 5/8).
  
  
  CONCLUSIONS
  The study of the expression of efflux pumps by q-PCR could be a useful diagnostic tool for early detection of azole resistance in C. albicans.
authors.forename: Marisol
authors.initials: M
authors.lastname: Fuentes
authors.forename: Germán
authors.initials: G
authors.lastname: Hermosilla
authors.forename: Claudio
authors.initials: C
authors.lastname: Alburquenque
authors.forename: Mary A
authors.initials: MA
authors.lastname: Falconer
authors.forename: José
authors.initials: J
authors.lastname: Amaro
authors.forename: Cecilia
authors.initials: C
authors.lastname: Tapia
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D002677:Chile; D025141:Drug Resistance, Fungal; D005260:Female; D015725:Fluconazole / Q000494:pharmacology*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D006801:Humans; D012331:RNA, Fungal / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D065819:Voriconazole / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D012331:RNA, Fungal; D015725:Fluconazole; D065819:Voriconazole