Cryptococcus neoformans: A Sugar-Coated Killer
The main principles for the genetic pathophysiology of cryptococcosis will probably be consistent among all three varieties. In this chapter the author considers the yeasts to be different varieties or serotypes. Seven major areas are examined to support the potential molecular insights into this pathogenic yeast which will allow one to identify drug targets, define drug resistance mechanisms, and/or prepare mutants or fungal products for protective fungal vaccines. Initial molecular biology studies focused on distinguishing molecular strain differences with the use of karyotypes, repetitive elements, and eventually randomly amplified polymorphic DNAs, amplification fragment length polymorphisms, and PCR fingerprinting for strain genotyping. Cryptococcus neoformans has several well-characterized virulence phenotypes which have been approached in their understanding by both genetic and molecular tools. Experimental cryptococcosis in animal models has tended to be associated with large inocula or some type of induced immunosuppression. In summary, the encapsulated yeast C. neoformans has developed into a major human pathogen over the last two decades. It causes a serious infection which we can treat, but it is still associated with substantial morbidity and mortality and is correctly called the sugar-coated killer In C. neoformans, all the keys are in place to unlock the mysteries of what it means to be a fungal pathogen. This basidiomycete has become a model pathogen for the study of molecular fungal pathogenesis, and although it has unique features, many of the paradigms discovered by its study will be used to understand other invasive mycoses.
