ABSTRACT
Cryptococcosis is one of the life-threatening infectious diseases seen in patients with acquired immunodeficiency syndrome (AIDS). The pathogen causing this disease is Cryptococcus neoformans, an encapsulated yeastlike fungus that is found throughout the world and is related to several other nonpathogenic species. All cryptococcal species have urease activity; however, C. neoformans can be distinguished from nonpathogenic species by its virulence for mice and growth at 37°C.
