On Sabouraud's dextrose agar colonies are cream colored, smooth, mucoid and yeast-like in appearance. Microscopic morphology shows globose to ovoid budding yeast-like cells or blastoconidia, 3.5-8.8 x 5.5-10.2 um in size.
India Ink Preparation: Positive - distinct capsules surrounding the yeast cells are present.
Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Budding yeast cells only. No pseudohyphae present.
Germ Tube test is Negative
Hydrolysis of Urea is Positive
Growth on Cycloheximide medium is Negative
Growth at 37C is Negative (Positive)
Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.
Negative: Glucose; Sucrose; Lactose; Galactose; Maltose; Trehalose.
Positive: Potassium nitrate; Glucose; Maltose (weak); Sucrose; Trehalose (weak); D-Xylose (weak); Melezitose; Raffinose (weak); Cellobiose; Inositol; L-Arabinose (weak); D-Mannitol (weak); Citric acid (weak); Succinic acid (weak); Salicin; D-Glucitol.
Variable: Soluble Starch; Lactose; Galactose; Melibiose; L-Rhamnose; D-Arabinose; Ribitol; L-Sorbose; D-Ribose; Galactitol; DL-Lactic acid.
Negative: Erythritol; Glycerol (some positive).
Cryptococcus albidus is a common transient on human skin and it has also been reported as a rare cause of pulmonary, CNS and vaginal infection. However, these reports must be viewed with considerable caution, as the culture identifications have not been verified.
Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.
Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.