Proteomics and its Application to the Human-Pathogenic Fungi Aspergillus fumigatus and Candida albicans

The number of opportunistic fungal infections has increased significantly during the past decades, at least in part as the result of a rising number of immunocompromised patients. Individuals at risk for the development of a serious fungal infection include patients undergoing solid-organ, blood and bone marrow transplantation, cancer patients, patients of the acquired immunodeficiency syndrome (AIDS) and other patients receiving immunosuppressive treatment (Pfaller and Diekema 2004; Brakhage 2005). Today, invasive fungal infections are among the most challenging problems in haematology, oncology and intensive care medicine (Vandewoude et al.2006). Amongthe approximately 140 000 known fungal species only a few cause human infections (Richardson 2003). The most predominant pathogens are the yeast Candida albicans and the filamentous fungus Aspergillus fumigatus, but also other fungal pathogens frequently cause systemic infections, such as the yeast species C. glabrata, C. krusei, C. tropicalis, Cryptococcus and Trichosporon, filamentous fungi such as Aspergillus, Fusarium, Rhizopus and Mucor, and dematiaceous hyphomycetes (Richardson 2005).

This chapter outlines a general overview of the two methods used for proteomic studies: 2D gel electrophoresis and liquid chromatography coupled to mass spectrometry, putting the main emphasis on gel-based proteomics. Since the number of publications about proteomics is tremendous and not all aspects can be discussed, the reader is referred in some cases to excellent reviews. Subsequently, recent advances in the proteomic analysis of C. albicans and A. fumigatus are discussed. Until now, there are only a few studies for A. fumigatus, but a lot of knowledge has already been gained for C. albicans and proteomic investigations were reviewed by Niimi et al. (1999), Pitarch et al. (2003, 2006b, c, 2007), Rupp (2004) and Thomas et al. (2006b).