DESCRIPTIONS OF MEDICAL FUNGI

Descriptions of Medical Fungi 67
Cryptococcus albidus (Saito) Skinner
Synonymy: Cryptococcus diffluens (Zach) Lodder & Kreger-van Rij.
RG-1 organism.
Culture: Colonies (SDA) are cream-coloured smooth, mucoid, glabrous, yeast-like.
Microscopy: Globose to ovoid budding yeast-like cells, 3.5-8.8 x 5.5-10.2 μm.
Pseudohyphae are absent.
India Ink Preparation: Positive - distinct thin capsules are present.
Physiological Tests: + Positive, - Negative, v Variable, w Weak, s Slow
Germ Tube - L-Sorbose v L-Arabinose + D-Glucitol +
Fermentation Sucrose + D-Arabinose v α-M-D-glucoside v
Glucose - Maltose + D-Ribose v D-Gluconate +
Galactose - Cellobiose + L-Rhamnose v DL-Lactate v
Sucrose - Trehalose +,w D-Glucosamine - myo-Inositol +
Maltose - Lactose v N-A-D-glucosamine - 2-K-D-gluconate +
Lactose - Melibiose v Glycerol v D-Glucuronate +
Trehalose - Raffinose + Erythritol v Nitrate +
Assimilation Melezitose + Ribitol v Urease +
Glucose + Soluble Starch v Galactitol v 0.1% Cycloheximide -
Galactose v D-Xylose + D-Mannitol + Growth at 37 O C v
Cryptococcus albidus has variable growth at 37 O C, and infections in humans are
rare. Along with C. laurentii, C. albidus accounts for 80% of the non-neoformans/gattii
infections. Impaired cellular immunity is the most common risk factor with HIV infection
and low CD4 counts a common comorbidity.
Antifungal Susceptibility: C. albidus (Australian National data); MIC µg/mL.
Note: All Cryptococcus species are intrinsically resistant to echinocandins.
No. 64
AmB 1 1
FLU 1 1
VORI 1 1
POSA 1 1
ITRA 1 1
5FC 1 1