Coloured light micrograph of Cryptococcus neoformans fungi, the cause of cryptococcosis. This yeast-like organism grows by budding in infected tissues and in culture at temperatures between 25 and 37 Celsius. Its most distinctive feature is the presence of an acidic mucopolysaccharide capsule (blue) which completely encloses the fungus. Cryptococcosis is a rare infection and affects people with a deficient immune system such as in AIDS. It is caused by inhaling the fungus found in soil contaminated by pigeon droppings. Infection may cause meningitis or granular growths in the lungs, skin or elsewhere. Magnification: x1500 at 6x4.5cm size.