Candida lusitaniae
On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous subglobose, ovoid, or elliptical budding yeast-like cells or blastoconidia, 1.5-6.0 x 2.5-10.0 um in size.
India Ink Preparation: Negative - no capsules present.
Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant pseudohyphae with short chains of blastoconidia.
Physiological Tests:
Germ Tube test is Negative
Hydrolysis of Urea is Negative
Growth on Cycloheximide medium is Negative
Growth at 37C is Positive
Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.
Positive: Glucose; Sucrose (delayed); Trehalose (delayed).
Variable: Galactose; Maltose.
Negative: Lactose.
Assimilation Tests:
Positive: Glucose; Maltose; Sucrose; Trehalose; D-Xylose; Glycerol; Cellobiose; L-Rhamnose; D-Ribose (delayed); D-Mannitol; Ribitol; D-Glucitol; Salicin; DL-Lactic acid; Succinic acid.
Variable: Galactose; Melezitose; D-Arabinose; L-Arabinose; L-Sorbose; Citric acid.
Negative: Potassium nitrate; Lactose; Raffinose; Melibiose; Galactitol; Erythritol; Inositol; Soluble Starch.
Clinical significance:
Candida lusitaniae has been isolated from several cases of disseminated candidiasis, including septicemia and pyelonephritis. It has also been reported to colonize the human respiratory, gastrointestinal and urinary tracts and many strains have proven to be resistant to amphotericin B. C. lusitaniae was first isolated from the alimentary tract of warm blooded animals and environmental isolations have been made from cornmeal, citrus peel, fruit juices, and milk from cows with mastitis. C. lusitaniae may also be difficult to distinguish from C. tropicalis using some yeast identification systems.
Mycosis: Candidiasis
Further reading:
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.
