Fungi are eukaryotic microorganisms that are closely related to humans at cellular level. Human fungal pathogens belong to various classes of fungi, mainly zygo- cetes, ascomycetes, basidiomycetes, and deuteromycetes. In recent years, fungal infections have dramatically increased as a result of improved diagnosis, high frequency of catheterization, instrumentation, etc. However, the main cause remains the increasing number of immunosuppressed patients, mostly because of HIV infection and indiscriminate usage of antineoplastic and immunosuppressive agents, broad-spectrum antibiotics and prosthetic devices, and grafts in clinical settings. Presently available means of combating fungal infections are still weak and clumsy compared to control of bacterial infection. The present scenario of antifungal therapy is still based on two classes of antifungal drugs (polyenes and azoles). These drugs are effective in many cases, but display toxicity and limited spectrum of ef?cacy. The recent trend towards emergence of drug-resistant isolates in the clinic is an additional problem. In recent years, a few new antifungal drugs have entered the clinics, but they are expected to undergo same fate as the older antifungal drugs. The application of fungal genomics offers an unparalleled opportunity to develop novel antifungal drugs. However, it is too early to expect any novel drugs, as the antifungal drug discovery program is in the stage of infancy. Interestingly, several novel antifungal drug targets have been identi?ed and validated.
