Candida albicans
Synonym: Candida stellatoidea
Culture of Candida albicans.
On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows spherical to subspherical budding yeast-like cells or blastoconidia, 2.0-7.0 x 3.0-8.5 um in size.
Bubbing yeast cells of Candida albicans
India Ink Preparation: Negative - no capsules present.
Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Pseudohyphae with blastoconidia and terminal vesicles (chlamydoconidia).
Physiological Tests:
Germ Tube test is Positive within 3 hours
Hydrolysis of Urea is Negative
Growth on Cycloheximide medium is Positive
Growth at 37C is Positive
Germ-tubes of Candida albicans
Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.
Positive: Glucose; Maltose.
Variable: Galactose; Trehalose.
Negative: Sucrose (some strains positive); Lactose.
Assimilation Tests:
Positive: Glucose; Maltose; Galactose; Trehalose; Sucrose (some negative);D-Xylose; Soluble Starch; D-Mannitol; D-Glucitol (Delayed).
Variable: Melezitose; Glycerol; Succinic acid; L-Arabinose; L-Sorbose; D-Ribose (some positive); Citric acid; DL-Lactic acid.
Negative: Potassium nitrate; Lactose; Ribitol (some positive); Raffinose; Cellobiose; Melibiose; Erythritol; Inositol; L-Rhamnose; D-Arabinose; Galactitol; Salicin.
MIC data is limited. Antifungal susceptibility testing of individual strains is recommended.
| Antifungal | MIC ug/mL | Antifungal | MIC ug/mL |
||
Range |
MIC90 |
Range |
MIC90 |
||
| Fluconazole | 0.03->64 |
2 |
Amphotericin B | 0.03-4 |
0.25 |
| Itraconazole | 0.008->8 |
0.125 |
Flucytosine | 0.03->64 |
0.5 |
| Posaconazole | 0.008->8 |
0.016 |
Caspofungin | 0.003->4 |
0.125 |
| Voriconazole | 0.008->8 |
0.03 |
Anidulafungin | 0.008->8 |
nd |
Clinical significance:
Candida albicans occurs naturally as a commensal of mucous membranes and in the digestive tract of humans and animals. It accounts for up to 70% of Candida species isolated from sites of infection and has been reported as a causative agent of all types of candidiasis. Environmental isolations are usually from sources contaminated by human or animal excreta, such as polluted water, soil, air and plants.
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
