Fungi in Bronchiectasis: A Concise Review

Abstract

Although the spectrum of fungal pathology has been studied extensively in immunosuppressed patients, little is known about the epidemiology, risk factors, and management of fungal infections in chronic pulmonary diseases like bronchiectasis. In bronchiectasis patients, deteriorated mucociliary clearance-generally due to prior colonization by bacterial pathogens-and thick mucosity propitiate, the persistence of fungal spores in the respiratory tract. The most prevalent fungi in these patients are Candida albicans and Aspergillus fumigatus; these are almost always isolated with bacterial pathogens like Haemophillus influenzae and Pseudomonas aeruginosa, making very difficult to define their clinical significance. Analysis of the mycobiome enables us to detect a greater diversity of microorganisms than with conventional cultures. The results have shown a reduced fungal diversity in most chronic respiratory diseases, and that this finding correlates with poorer lung function. Increased knowledge of both the mycobiome and the complex interactions between the fungal, viral, and bacterial microbiota, including mycobacteria, will further our understanding of the mycobiome's relationship with the pathogeny of bronchiectasis and the development of innovative therapies to combat it.

Keywords: Aspergillus; Candida albicans; allergic bronchopulmonary aspergillosis; bronchiectasis; filamentous fungi; fungi; mycobiome; yeast.

Figure 1

Pathogenic mechanisms of fungi in bronchiectasis.

Figure 2

Pathogenic potential of Aspergillus spp. (arrow direction means more severity).

Figure 3

Evolution of the mycobiome in patients with chronic respiratory disease. Information has been obtained from reference [72].