Evidence that the human pathogenic fungus Cryptococcus neoformans var. grubii may have evolved in Africa.
Abstract
Most of the species of fungi that cause disease in mammals, including Cryptococcus
neoformans var. grubii (serotype A), are exogenous and non-contagious. Cryptococcus
neoformans var. grubii is associated worldwide with avian and arboreal habitats. This
airborne, opportunistic pathogen is profoundly neurotropic and the leading cause of
fungal meningitis. Patients with HIV/AIDS have been ravaged by cryptococcosis--an
estimated one million new cases occur each year, and mortality approaches 50%. Using
phylogenetic and population genetic analyses, we present evidence that C. neoformans
var. grubii may have evolved from a diverse population in southern Africa. Our ecological
studies support the hypothesis that a few of these strains acquired a new environmental
reservoir, the excreta of feral pigeons (Columba livia), and were globally dispersed
by the migration of birds and humans. This investigation also discovered a novel arboreal
reservoir for highly diverse strains of C. neoformans var. grubii that are restricted
to southern Africa, the mopane tree (Colophospermum mopane). This finding may have
significant public health implications because these primal strains have optimal potential
for evolution and because mopane trees contribute to the local economy as a source
of timber, folkloric remedies and the edible mopane worm.
Type
Journal articleSubject
CryptococcosisCryptococcus neoformans
DNA, Fungal
Evolution, Molecular
Haplotypes
Humans
Molecular Sequence Data
Phylogeny
Recombination, Genetic
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https://hdl.handle.net/10161/11064Published Version (Please cite this version)
10.1371/journal.pone.0019688Publication Info
Litvintseva, Anastasia P; Carbone, Ignazio; Rossouw, Jenny; Thakur, Rameshwari; Govender,
Nelesh P; & Mitchell, Thomas G (2011). Evidence that the human pathogenic fungus Cryptococcus neoformans var. grubii may
have evolved in Africa. PLoS One, 6(5). pp. e19688. 10.1371/journal.pone.0019688. Retrieved from https://hdl.handle.net/10161/11064.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Anastasia P. Litvintseva
Adjunct Assistant Professor in the Department of Molecular Genetics and Microbiology
Thomas Greenfield Mitchell
Associate Professor Emeritus in Molecular Genetics and Microbiology
Among patients with AIDS, leukemia or other cancers, organ or bone marrow transplants,
and similar immunocompromising risk factors, the incidence of opportunistic mycoses
and the number of different fungal pathogens are increasing dramatically. For many
of these fungi, the definition of a species and the recognition of pathogen are highly
problematic. Conventional methods of identification are based on morphological and
physiological characteristics and are often time-consuming, difficult to int
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