Prevalence and diversity of filamentous fungi in the airways of cystic fibrosis patients - A Dutch, multicentre study.
BACKGROUND
Progressive lung injury in Cystic Fibrosis (CF) patients can lead to chronic colonization with bacteria and fungi. Fungal colonization is obtained from the environment which necessitates locally performed epidemiology studies. We prospectively analyzed respiratory samples of CF patients during a 3-year period, using a uniform fungal culture protocol, focusing on filamentous fungi and azole resistance in Aspergillus fumigatus.


METHODS
Over a 3-year period, all respiratory specimens collected from CF patients in 5 Dutch CF centers, were analyzed. Samples were inoculated onto the fungal culture media Sabouraud dextrose agar (SDA) and Medium B+. All fungal isolates were collected and identified in one centre, using Amplified Fragment Length Polymorphism (AFLP) fingerprinting, rDNA PCR and ITS, calmodulin and β-tubulin sequencing. Azole resistance was assessed for all A. fumigatus using a qPCR assay followed by phenotypic confirmation.


RESULTS
Filamentous fungi were recovered from 699 patients from at least one respiratory sample, corresponding with 3787 cultured fungal species. A. fumigatus was cultured most often with a mean prevalence of 31.7%, followed by Penicillium species (12.6%), non-fumigatus Aspergillus species (5.6%), Scedosporium species (4.5%) and Exophiala dermatitidis and Cladosporium species (1.1% each). In total 107 different fungal species were identified, with 39 Penicillium species and 15 Aspergillus species. Azole resistance frequency in A. fumigatus was 7.1%, with TR34/L98H being the dominant resistance mechanism.


CONCLUSION
A vast diversity of filamentous fungi was demonstrated, dominated by Aspergillus and Penicillium species. We observed a mean azole resistance prevalence of 7.1% of A. fumigatus culture positive patients.
['Engel|Tobias G P|TGP|', 'Slabbers|Lydie|L|', 'de Jong|Carmen|C|', 'Melchers|Willem J G|WJG|', 'Hagen|Ferry|F|', 'Verweij|Paul E|PE|', 'Merkus|Peter|P|', 'Meis|Jacques F|JF|', '|||']
D000328:Adult D000935:Antifungal Agents D002648:Child D003550:Cystic Fibrosis D018450:Disease Progression D025141:Drug Resistance, Fungal D005260:Female D005658:Fungi D006801:Humans D008297:Male D008826:Microbial Sensitivity Tests D008828:Microbiological Techniques D009426:Netherlands D015995:Prevalence D012137:Respiratory System D012307:Risk Factors D013048:Specimen Handling D013183:Sputum
Filamentous fungi Cystic Fibrosis Epidemiology Azole resistance Aspergillus Penicillium