Pathogenicity and virulence of Aspergillus fumigatus

Abstract

Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.

Keywords: Aspergillosis; Aspergillus fumigatus; Pathogenicity; Virulence factors; at-risk factors.

Figure 1.

A. fumigatus lifecycle both in the environment and a human host. A. fumigatus can enter an asexual (blue) or sexual (red) reproductive cycle. During the sexual cycle, the fungus undergoes meiotic recombination to form the cleistothecium, which contains ascospores. Dead plant matter is an ideal environmental niche for C. fumigatus to sporulate and grow. During the asexual cycle, the mycelium generates spores, which can be aerially dispersed. Some of these conidia land in a new ecological niche, while others are inhaled by humans and can cause disease (green).

Figure 2.

Diagram of innate immune response against Aspergillus fumigatus. This figure schematically represents an overview of the information presented in this review regarding epithelial cell, macrophage, neutrophil, and dendritic cell interactions with A. fumigatus.