Cryptococcosis:
Infections of the CNS and pulmonary system caused by
Cryptococcus neoformans and
Cryptococcus gattii.
- These fungi are found in bird droppings, and, by association, soil and trees.
- They are encapsulated, spherical yeast
– Outer "halo" is the polysaccharide capsule
– Inner yeast cell has melanin in its cell wall.
Cryptococcus* is inhaled into the respiratory system, followed by dissemination to and localization within the CNS.
Cryptococcus neoformans is a major opportunistic pathogen in AIDS patients.*
- Cryptococcosis typically manifests as CNS infections:
–
Meningitis and encephalitis
– In the image, we can see the characteristic "soap bubble" lesions of
Cryptococcal encephalitis.
Cryptococcus neoformans* CNS infection is associated with immunosuppressed patients
- Cryptococcus gattii tend to produce infection in relatively immunocompetent individuals
– These patients tend to have more granuloma formation
– Some authors suggest that so-called immunocompetent patients actually have complicating illnesses or histories of immunosuppression).
- Cryptococcosis can also manifest as pulmonary infection, sometimes following CNS involvement.
– In the lungs, severity ranges from asymptomatic to pneumonia with pulmonary infiltrates.
–
Cryptococcus gattii tends to produce larger pulmonary lesions than
Cryptococcus neoformans.
