Given the neurotropic nature of the fungus, the most common clinical form of cryptococcosis is meningoencephalitis. Pathogenicity and Clinical SignificanceĬryptococcus neoformans is the causative agent of cryptococcosis. See the summary of synonyms and teleomorph-anamorph relations for the Cryptococcus spp. Similarly, the mating of serotypes B or C forms the teleomorph called Filobasidiella neformans var. If the strains of serotypes A or D mate with each other, Filobasidiella neoformans var. The teleomorphic (sexual) reproductive phase of Cryptococcus that occurs in nature constitutes the genus Filobasidiella. are Cryptococcus albidus, Cryptococcus laurentii, Cryptococcus terreus, Cryptococcus uniguttulatus, Cryptococcus luteolus and Cryptococcus gastricus. The definitive identification of the two varieties is possible by biochemical tests, such as resistance to canavanine, use of glycine as the sole carbon and nitrogen source, and resistance of their urease enzymes to EDTA. The two varieties, neoformans and gattii are morphologically similar, except that basidiospores of var. This leaves serotype D as the sole serotype in var. grubii, be created to contain serotype A. Thus, it was recently proposed that a new variety, var. However, in addition to the previously observed phenotypic differences, recent molecular studies have detected significant genetic variations between the two serotypes. neoformans while serotypes B and D were included in var. Until recently and traditionally, serotypes A and D were included in var. Cryptococcus neoformans was generally accepted to include two varieties var. Serotyping is based on capsular agglutination reactions and can be detected by a dot enzyme assay. Among these, Cryptococcus neoformans is the only species that is pathogenic and will be discussed in this page. The genus Cryptococcus includes around 37 species. gattii was also isolated from goats with pulmonary disease. neoformans) or eucalyptus trees and decaying wood forming hollows in living trees ( Cryptococcus neoformans var. Following its first identification in nature from peach juice samples, the major environmental sources of Cryptococcus neoformans have been shown to be either soil contaminated with pigeon droppings ( Cryptococcus neoformans var. neoformans Description and Natural HabitatsĬryptococcus is an encapsulated yeast.
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