Cryptococcus neoformans var grubii

Cryptococcus neoformans is a pathogenic yeast that causes debilitating disease of the central nervous system and other organs in humans. C. neoformans normally resides in the environment, where it is most commonly associated with avian guano and vegetative debris.
On the basis of differences in capsular epitopes and clinical manifestations, two varieties and three serotypes of C. neoformans have been recognized. The most common variety, C. neoformans var. grubii, includes isolates of serotype A, which are widespread and responsible for 80% of cryptococcal infections and for 99% of the infections in patients with AIDS. The other variety, C. neoformans var. neoformans, includes strains of serotype D, which also infects immunocompromised individuals; however, the prevalence of this variety is lower, and it is considered less pathogenic.
Strains of serotype AD are hybrids between strains of serotypes A and D.

This MLST scheme is designed to differentiate between individuals of Cryptococcus neoformans var grubii (serotype A) based on the twelve loci developed by Ana Litvinseva and reported in the following reference:

Litvintseva, A. P., Thakur, R., Vilgalys, R., Mitchell, T. G. Multilocus Sequence Typing Reveals Three Genetic Subpopulations of Cryptococcus neoformans var. grubii (Serotype A), Including a Unique Population in Botswana. Genetics 2006 172: 2223-2238