The Airway Colonization by Opportunistic Filamentous Fungi in Patients with Cystic Fibrosis: Recent Updates

Abstract

There has been a remarkable increase recently in the isolation of fungi such as Aspergillus fumigatus, species of the Pseudallescheria boydii/Scedosporium apiospermum complex, and Exophiala sp. from the respiratory tract of patients with cystic fibrosis (CF). This review describes the recent insights into the epidemiology, ecology, and physiopathology of the filamentous fungi able to colonize and/or to infect the airways of CF patients, and that may be responsible for accelerated lung function decline. We summarize salient features not only on highly prevalent species such as Aspergillus and Scedosporium, but also on more recently described fungi such as Rasamsonia argillacea. In addition, we discuss the challenges inherent in tracking and interpreting rates of fungal colonization/infection in the CF patient population, taking into consideration the polymicrobial composition of the CF lung environment, the corresponding cross-kingdom interactions, and the new concept of mycobiota. Further research is warranted to clarify the role of fungi in CF lung disease and its therapeutic management.