Chapter 18

Environmental Niches for Cryptococcus neoformans and Cryptococcus gattii

Thomas G. Mitchell

Thomas G. Mitchell

Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710

Search for more papers by this author
Elizabeth Castañeda

Elizabeth Castañeda

Emerita Investigator, Instituto Nacional de Salud, Bogotá, Colombia

Search for more papers by this author
Kirsten Nielsen

Kirsten Nielsen

Department of Microbiology, Medical School, University of Minnesota, Minneapolis, MN, 55455

Search for more papers by this author
Bodo Wanke

Bodo Wanke

Mycology Laboratory, Instituto de Pesquisa Clínica Evandro Chagas-Fiocruz, Rio de Janeiro, RJ, Brazil

Search for more papers by this author
Marcia S. Lazéra

Marcia S. Lazéra

Mycology Laboratory, Instituto de Pesquisa Clínica Evandro Chagas-Fiocruz, Rio de Janeiro, RJ, Brazil

Search for more papers by this author
First published: 12 November 2010

Summary

This chapter focuses on the environmental habitats of the dominant human-pathogenic species, Cryptococcus neoformans and Cryptococcus gattii, and their varieties and subgroups. The procedures for isolating C. gattii from any environmental sample are the same as those for C. neoformans. Several researchers have sampled specific sites temporally and spatially. Many have included a variety of telluric, arboreal, aquatic, and aerial niches. C. neoformans was recovered from 62 samples of decayed wood from the hollows of five pink shower trees, two fig trees, and one November shower tree. The majority of patients diagnosed with cryptococcal meningitis in Teresina resided in Piauḭ or the adjacent state of Maranhão. Strains of VNI can readily be isolated from pigeon feces, and they are able to grow and mate on media containing pigeon feces. As cited in the chapter, the rare environmental strains of VNII have included isolations from pigeon and arboreal habitats, but their numbers have been too low to define the ecological niche of this molecular type. C. gattii is rarely isolated from pigeon feces but is associated with various tree species in Australia, Asia, North America, and South America. These different environmental niches have led to the hypothesis that C. neoformans is ubiquitous in the environment due to dissemination by pigeons following migratory and trade routes and that C. gattii is restricted to tropical and subtropical regions because it is not associated with pigeons.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.