Ecology of Cryptococcus neoformans

Cryptococcus neoformans is a basidiomycetous, yeast-like fungus which, following inhalation from an environmental source, causes respiratory and neurological disease in humans and animals. Though the ecology of C. neoformans is poorly understood, recent observations provide clues about its life-cycle in nature. Two biotypes of C. neoformans are recognised, C. neoformans var. neo-formans (serotypes A, D, AD) and C. neoformans var. gattii (serotypes B, C). C. neoformans var. neoformans. This biotype has been isolated from various sources in nature and is noted for its association with accumulations of avian guano, especially pigeon excreta. It has also been isolated from droppings of caged birds including canaries, parrots and budgerigars. Other environmental isolations have bee