Fungus
Cryptococcus gattii
Encapsulated yeast affecting immunocompetent hosts
krip-toh-KOK-us GAT-ee-eye
High-yield clue
Encapsulated yeast causing meningitis or a mass-like lesion (cryptococcoma) in an immunocompetent host is the core study clue.
Overview
An encapsulated environmental yeast related to Cryptococcus neoformans that classically causes lung and CNS disease in apparently immunocompetent people. Key teaching contrast to C. neoformans on host status and geography.
Classification
- Encapsulated yeast
- Basidiomycota
- Narrow-based budding
- Polysaccharide capsule
- Environmental (tree-associated)
Lab & identification clues
- Encapsulated narrow-based budding yeast microscopy vocabulary
- Capsule highlighted by negative-stain preparation vocabulary
- Cryptococcal antigen shared with C. neoformans vocabulary
- Melanin/urease positivity as genus vocabulary
Associations
- Disease in immunocompetent hosts more often than C. neoformans
- Emerged in the Pacific Northwest/Vancouver Island vocabulary
- Classic association with eucalyptus and other trees
- Cryptococcoma mass lesions and meningoencephalitis vocabulary
Commonly confused with
- Cryptococcus neoformans (pigeon-associated, mostly immunosuppressed hosts)
- Candida species (yeast, no large capsule)
Frequently asked questions
What is Cryptococcus gattii?
An encapsulated environmental yeast related to Cryptococcus neoformans that classically causes lung and CNS disease in apparently immunocompetent people. Key teaching contrast to C. neoformans on host status and geography.
What are the lab clues for Cryptococcus gattii?
Lab clues for Cryptococcus gattii include Encapsulated narrow-based budding yeast microscopy vocabulary, Capsule highlighted by negative-stain preparation vocabulary, Cryptococcal antigen shared with C. neoformans vocabulary, and Melanin/urease positivity as genus vocabulary.
What is Cryptococcus gattii commonly confused with?
Cryptococcus gattii is commonly confused with Cryptococcus neoformans (pigeon-associated, mostly immunosuppressed hosts); Candida species (yeast, no large capsule).
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.