Aspergillus species and other molds in respiratory samples from patients with cystic fibrosis: a laboratory-based study with focus on Aspergillus fumigatus azole resistance

Klaus Leth Mortensen, Rasmus Hare Jensen, Helle Krogh Johansen, Marianne Skov, Tanja Pressler, Susan Julie Howard, Howard Leatherbarrow, Emilia Mellado, Maiken Cavling Arendrup

156 Citations (Scopus)

Abstract

Respiratory tract colonization by molds in patients with cystic fibrosis (CF) were analyzed, with particular focus on the frequency, genotype, and underlying mechanism of azole resistance among Aspergillus fumigatus isolates. Clinical and demographic data were also analyzed. A total of 3,336 respiratory samples from 287 CF patients were collected during two 6-month periods in 2007 and 2009. Azole resistance was detected using an itraconazole screening agar (4 mg/liter) and the EUCAST method. cyp51A gene sequencing and microsatellite genotyping were performed for isolates from patients harboring azole-resistant A. fumigatus. Aspergillus spp. were present in 145 patients (51%), of whom 63 (22%) were persistently colonized. Twelve patients (4%) harbored other molds. Persistently colonized patients were older, provided more samples, and more often had a chronic bacterial infection. Six of 133 patients (4.5%) harbored azole-nonsusceptible or -resistant A. fumigatus isolates, and five of those six patients had isolates with Cyp51A alterations (M220K, tandem repeat [TR]/L98H, TR/L98H-S297T-F495I, M220I-V101F, and Y431C). All six patients were previously exposed to azoles. Genotyping revealed (i) microevolution for A. fumigatus isolates received consecutively over the 2-year period, (ii) susceptible and resistant isolates (not involving TR/L98H isolates) with identical or very closely related genotypes (two patients), and (iii) two related susceptible isolates and a third unrelated resistant isolate with a unique genotype and the TR/L98H resistance combination (one patient). Aspergilli were frequently found in Danish CF patients, with 4.5% of the A. fumigatus isolates being azole nonsusceptible or resistant. Genotyping suggested selection of resistance in the patient as well as resistance being achieved in the environment.
Original languageEnglish
JournalJournal of Clinical Microbiology
Volume49
Issue number6
Pages (from-to)2243-51
Number of pages9
ISSN0095-1137
DOIs
Publication statusPublished - 1 Jun 2011

Keywords

  • Adolescent
  • Adult
  • Antifungal Agents
  • Aspergillus fumigatus
  • Azoles
  • Child
  • Child, Preschool
  • Cystic Fibrosis
  • Cytochrome P-450 Enzyme System
  • Drug Resistance, Fungal
  • Female
  • Fungal Proteins
  • Fungi
  • Genotype
  • Humans
  • Infant
  • Lung Diseases, Fungal
  • Male
  • Microbial Sensitivity Tests
  • Microsatellite Repeats
  • Middle Aged
  • Mutation, Missense
  • Mycological Typing Techniques
  • Prevalence
  • Young Adult

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