Blastoschizomyces capitatis

Synonym: Trichosporon capitatis

On Sabouraud's dextrose agar colonies are white to cream colored, wrinkled and dull in appearance with a mycelial fringe. Microscopic morphology showing oval to long-oval blastoconidia 3.5-6.7 x 7.4-12.3 um in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: True mycelium and arthroconidia are abundant. The blastoconidia usually form clusters along or at the end of the hyphae.

Physiological Tests:

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

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

Negative: Glucose; Sucrose; Lactose; Galactose; Maltose; Trehalose.

Assimilation Tests:

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

Blastoschizomyces capitatum is distinguished from Trichosporon beigelii by being lactose negative.

Clinical significance:

Blastoschizomyces capitatis is a common environmental fungus and transient component of the normal skin flora, it is frequently isolated from sputum. Disseminated infections involving the spleen, liver, kidney, lung and brain have been reported in neutropenic patients with leukemia or from those undergoing bone marrow transplantation. Blood cultures are often positive and skin lesions similar to disseminated candidiasis may also be present.

Mycosis: Miscellaneous Yeast Infections

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.