[Putative virulence factors of Aspergillus species].

Members of the genus Aspergillus are filamentous, ubiquitous fungi found in nature. Aspergillus species can cause clinical settings in man, such as opportunistic infections, allergic states and toxicoses. Immunosuppression is the major factor predisposing to development of opportunistic mycoses. To invade the host, Aspergillus species must be able to adhere to and penetrate the host tissues. Much work has focused on the search for virulence determinants that allow the establishment of the fungus within the host. Adhesins, pigment production, toxic metabolites and extracellular enzymes are thought to be the putative virulence factors of Aspergillus species. Adhesion systems provide binding of conidia to various circulating or basement membrane-associated host proteins; toxic molecules inhibit macrophage phagocytosis and mucociliary action; pigment production aids in longer survival in tissues and also overwhelms the host defence systems; extracellular enzymes degrade the structural barriers in the host. In this review, putative virulence factors of Aspergillus species and their potential role in aspergillosis have been discussed.