The Fungus among Us: Cryptococcus neoformans and Cryptococcus gattii Ecological Modeling for Colombia

Abstract

The environmental isolation of Cryptococcus spp. is typically a difficult undertaking. Collecting samples in the field is costly in terms of travel, personnel time and materials. Furthermore, the recovery rate of Cryptococcus spp. may be very low, thereby requiring a large number of samples to be taken without any guarantee of success. Ecological niche modeling is a tool that has traditionally been used to forecast the distribution of plant and animal of species for biodiversity and conservation purposes. Here, we use it in a public health application to produce risk area maps for cryptococcal disease in Colombia. The Genetic Algorithm for Ruleset Production (GARP) was used to create models for Cryptococcus neoformans (C. neoformans) and Cryptococcus gattii (C. gattii), based on environmental sampling and clinical records data recorded since 1987. These maps could be used to focus public health messaging related to cryptococcal disease, and it enables us to characterize the ecological niche for Cryptococcus in Colombia. We found that the ecological niche for C. gattii in Colombia is quite diverse, establishing itself in sub-tropical and temperate ecoregions within the country. This suggests that C. gattii is highly adaptive to different ecological conditions in Colombia and different regions of the world.

Genomic epidemiology of Cryptococcus yeasts identifies adaptation to environmental niches underpinning infection across an African HIV/AIDS cohort

“…Other studies which aimed to model the fundamental niche of the pathogen identified relevant climatic and spatial variables to study the distribution of Cryptococcus using a jackknifing procedure (Mak ; Mak et al . ). In the present study, the same environmental variables were explored.…”

The status of cryptococcosis in Latin America

“…Following Lazera’s findings, tree hollows, decayed wood and soil samples have been described as the habitat of C. gattii , and C. neoformans in a plethora of indigenous and imported trees in some Latin-American countries, including: Argentina ( Refojo et al 2009 , Mazza et al 2013 , Cattana et al 2014 ), Brazil ( Costa et al 2009 , Andrade-Silva et al. 2012 , Anzai et al 2014 , Brito-Santos et al 2015 , Castro e Silva et al 2016 ), Chile (Toro-Zúñiga et al 2015), Colombia ( Escandón et al 2005 , Escandón et al 2010 , Firacative et al 2011 , Mak et al 2015 , Noguera et al 2015 , Vélez and Escandón 2017 ), and Cuba ( Illnait-Zaragozí et al 2010a , Illnait-Zaragozí et al 2012 ) ( Table V ). Some of the trees genus and species that are the reservoir of C. gattii as well as C. neoformans are: E. camaldulensis , E. tereticornis , Eucalyptus spp., Acacia spp., Corymbia ficifolia , Phoenix spp., Tipuana tipui , Moquilea tomentosa , Cassia grandis , Ficus spp .…”

“…Particularly in Colombia, a study on ecological niche modelling was also used to forecast the distribution of cryptococcal species and to produce risk area maps for cryptococcal disease in the country ( Mak et al 2015 ). This study was conducted following the success of accurately identifying ecological niche areas of human and animal cases of C. gattii in British Columbia, Canada ( Mak et al 2010 ) and also complements the report on niche prediction of C. neoformans and C. gattii in Europe ( Cogliati et al 2017 ).…”

Cryptococcus bacillisporus (VGIII) Meningoencephalitis Acquired in Santa Cruz, Bolivia

“…C. gattii complex inhabit >50 tree species in a variety of ecosystems and climates [ 1 ]. The exact range and association to ecoclimatic zones in South America is uncertain, but ecological modeling studies from Colombia suggest that the distribution is wide and also includes ecoregions with temperate climate [ 15 ]. The Amazon rainforest with its botanical variety has been suggested as the origin of certain strains of higher virulence [ 1 ].…”