Cryptococcus species are invasive encapsulated yeast that causes cryptococcosis in the immunocompromised and, in rare cases, in the immunocompetent. The two Cryptococcus species that cause cryptococcosis are C. neoformans and C. gattii. C. neoformans is usually associated with infections in the immunocompromised, while C. gattii is associated with infections in the immunocompetent. The most common routes of exposure include contact with contaminated soil and bird droppings.
Cryptococcus exists in asexual forms (yeast) and sexual forms (teleomorph). Cryptococcus produces white mucoid colonies and grows on a multitude of media. C. neoformans and C. gattii are distinguished by growth features on canavanine-glycine-bromomethyl blue agar.
