Candida kefyr

Synonym: Candida pseudotropicalis

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous short-ovoid to long-ovoid, budding yeast-like cells or blastoconidia, 3.0-6.5 x 5.5-11.0 um, sometimes becoming elongate (up to 16.0 um) in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant, long, wavy, branched pseudohyphae is usually formed, with ovoid blastoconidia, budding off singly, in pairs or chains, often in a verticillated position. Note, in some strains pseudohyphae may be scarce or almost absent.

Physiological Tests:

Germ Tube test is Negative
Hydrolysis of Urea is Negative
Growth on Cycloheximide medium is Positive
Growth at 37C is Variable

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Galactose (delayed).
Variable: Glucose; Sucrose; Lactose; Maltose.
Negative: Trehalose.

Assimilation Tests:

Positive: Glucose; Galactose; Sucrose; Lactose; Raffinose; DL-Lactic acid.
Variable: Trehalose; D-Xylose; Glycerol; L-Arabinose; Cellobiose; L-Sorbose; D-Ribose; D-Mannitol; Salicin; Citric acid; Succinic acid.
Negative: Potassium nitrate; Ribito; Maltose; Melibiose; Galactitol; Erythritol; Inositol; D-Glucitol; Soluble Starch; L-Rhamnose; Melezitose; D-Arabinose.

Clinical significance:

Candida kefyr is a rare cause of candidiasis and is usually associated with superficial cutaneous manifestations rather than systemic disease. It has been isolated from nails and lung infections. Environmental isolations have been made from cheese and dairy products.

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.