Ph.D. thesis MOLECULAR ANALYSIS OF GENES ENCODING IRON TRANSPORT PROTEINS IN OPPORTUNISTIC PATHOGEN ZYGOMYCETES

2008 Introduction Several members of the class Zygomycetes have been reported as agents of opportunistic fungal infections designated as zygomycoses. They can cause severe and frequently fatal infections in debilitated or immunocompromised patients. Rhizopus, Mucor, Absidia and Rhizomucor species seem to be most frequently involved in human and animal mycotic diseases. The risk of development of zygomycosis increases first of all in diabetic (particularly associated with ketoacidosis) and immunocompromised patients associated with medical intervention. Neutropenia as a consequence of hematological malignancies is also serious predisposing factor to the development of disseminated zygomycosis. Burn injuries and extreme malnutrition are also risk factors, and patients on dialysis treated with the iron chelator deferoxamine form a specific risk group as well. Although zygomycoses are relatively rare, the incidence of such infections shows an increasing tendency due to the improved medical techniques (solid organ or bone-marrow transplantations, prolonged steroid treatment or chemotherapy). Therefore the number of patients at risk for zygomycosis is continuously increasing in line with the expanding population of the immunocompromised patients and the continuous rise of diabetes. This fact together with the associated high mortality rate (from 75 to 95 %), the difficulty of their diagnosis and their resistance to the most widely used antifungal drugs underline the importance of the studies on the molecular background of this infections and indicate that the development of new diagnostic and therapeutic methods is urgently needed. Molecular and serological diagnostic methods are still in the experimental phase, and