Cryptococcus is predominantly an AIDS-related pathogen that causes significant morbidity and mortality in immunocompromised patients. Research studies have historically focused on understanding how the organism causes human disease through the use of in vivo and in vitro model systems to identify virulence factors. Cryptococcus is not an obligate pathogen, however, as human–human transmission is either absent or rare. Selection in the environment must thus be invoked to shape the evolution of this taxa, and directly influences genotypic and trait diversity. Importantly, the evolution and maintenance of pathogenicity must also stem directly from environmental selection. To that end, here we examine abiotic and biotic stresses in the environment, and discuss how they could shape the factors that are commonly identified as important virulence traits. We identify a number of important unanswered questions about Cryptococcus diversity and evolution that are critical for understanding this deadly pathogen, and discuss how implementation of modern sampling and genomic tools could be utilized to answer these questions.
Bibliographical noteFunding Information:
We thank Samantha Arras, Paige Erpf, and Sheena Chua for helpful comments on the manuscript. The work was supported by National Institutes of Allergy and Infectious Disease R01AI080275 grant to K.N. and a Banting Postdoctoral Fellowship from the Canadian Institutes of Health Research to A.C.G.
- cryptococcal meningitis
- fungal pathogen