Difference in Cryptococcus neoformans cellular and capsule size in sequential pulmonary and meningeal infection: a postmortem study.

Cryptococcus neoformans is an encapsulated yeast that primarily causes a life-threatening meningoencephalitis in immunosuppressed individuals especially those with HIV/AIDS. Its main virulence factor is its polysaccharide capsule which interferes with complement-mediated phagocytosis. C. neoformans infections ensue following inhalation of small desiccated less encapsulated propagules leading to pulmonary pneumonia or colonization of the host's respiratory tract. Numerous murine experimental studies have shown major discrepancies in cryptococcal cell and capsule enlargement between the lung and brain. In this report, we describe a nonmurine experimental model of the striking variability between cryptococcal cell and capsule size diameters in histology sections of postmortem lung and brain in a fatal cryptococcal infection in a heart transplant recipient.