title: High prevalence of triazole resistance in Aspergillus fumigatus, especially mediated by TR/L98H, in a French cohort of patients with cystic fibrosis.
abstract: OBJECTIVE
  Triazole resistance in Aspergillus fumigatus due to a single azole resistance mechanism (TR/L98H) is increasingly reported in European countries. Data from patients with cystic fibrosis (CF) are limited. Our study aimed to investigate the prevalence and molecular mechanisms of azole resistance in A. fumigatus in a cohort of patients with CF.
  
  
  METHODS
  Eighty-five A. fumigatus isolates from 50 CF patients, collected between January 2010 and April 2011, were retrospectively analysed for azole resistance using agar plates containing 4 mg/L itraconazole. MICs of itraconazole, voriconazole and posaconazole were determined according to EUCAST methodology for each isolate able to grow on this medium. Species identification was performed by sequencing of the β-tubulin gene. Sequencing analysis of the cyp51A gene and its promoter region was conducted.
  
  
  RESULTS
  Nine isolates (four patients, 8% prevalence) were able to grow on itraconazole-containing agar plates. Itraconazole resistance was confirmed by EUCAST methodology (MICs >2 mg/L). All isolates had mutations in the cyp51A gene at residues previously involved in azole resistance: L98H (n = 5), M220T (n = 4) and G54R (n = 1). One patient had three genetically distinct azole-resistant isolates identified during the study. The isolates with L98H that were recovered from three patients (6% prevalence) also had the 34 bp tandem repeat in the promoter region of cyp51A (TR/L98H) and displayed multiazole resistance.
  
  
  CONCLUSIONS
  We report an 8% prevalence of itraconazole resistance in CF patients in our centre, mostly driven by TR/L98H (6%). Our data confirm that TR/L98H occurs in France and can be highly prevalent in CF patients.
authors.affiliation: Département de Parasitologie et Mycologie Médicale,  Université de Nantes, Nantes Atlantique Universités, EA1155-IICiMed, Faculté de Pharmacie, Nantes,  France.
authors.forename: Florent
authors.initials: F
authors.lastname: Morio
authors.forename: Guillaume G
authors.initials: GG
authors.lastname: Aubin
authors.forename: Isabelle
authors.initials: I
authors.lastname: Danner-Boucher
authors.forename: Alain
authors.initials: A
authors.lastname: Haloun
authors.forename: Emilie
authors.initials: E
authors.lastname: Sacchetto
authors.forename: Dea
authors.initials: D
authors.lastname: Garcia-Hermoso
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bretagne
authors.forename: Michel
authors.initials: M
authors.lastname: Miegeville
authors.forename: Patrice
authors.initials: P
authors.lastname: Le Pape
mesh_terms: D000293:Adolescent; D000328:Adult; D000935:Antifungal Agents / Q000494:pharmacology*; D001228:Aspergillosis / Q000382:microbiology; D001232:Aspergillus fumigatus / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000150:complications; D025141:Drug Resistance, Fungal; D005602:France; D006801:Humans; D066298:In Vitro Techniques; D017964:Itraconazole / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D011743:Pyrimidines / Q000494:pharmacology*; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D014230:Triazoles / Q000494:pharmacology*; D014404:Tubulin / Q000235:genetics; D065819:Voriconazole; D055815:Young Adult
chemical_list: D000935:Antifungal Agents; D011743:Pyrimidines; D014230:Triazoles; D014404:Tubulin; D017964:Itraconazole; C101425:posaconazole; D065819:Voriconazole