Description
The fungus Aspergillus belongs to the group of ascomycetes. These organisms develop branched mycelia. They spread through conidiospores which are released from mycelia as extremely resistant lasting spores. 20 species of Aspergillus are human pathogens being opportunistic infectious agents. The most important species is Aspergillus fumigatus.
Aspergillus fumigatus can cause multiple allergic and invasive diseases. The pathogenesis of an invasive Aspergillus infection takes place in several steps: The fungal spores are transmitted through the air as a so called "bioaerosol" and are absorbed by the lungs. Due to their size of about 3 µm they reach the lung alveoli. In case of an invasive aspergillosis fungus hyphae penetrate the bronchial mucosa and the surrounding lung parenchyma with the aid of released proteinases. The Aspergillus spores tend to penetrate the blood vessels and settle down in remote tissues after a hematogen dissemination