DESCRIPTIONS OF MEDICAL FUNGI

Descriptions of Medical Fungi 173
Rhodotorula mucilaginosa (Jorgensen) Harrison
Synonymy: Rhodotorula rubra (Demme) Lodder.
RG-1 organism.
Morphological Description: Colonies are coral pink, usually smooth, sometimes
reticulate, rugose or corrugated, moist to mucoid, yeast-like colonies. Spherical to
elongate budding yeast-like cells or blastoconidia, 2.5-6.5 x 6.5-14.0 µm.
India Ink Preparation: Small capsules present.
Molecular Identification: Requires sequencing of the ITS and/or D1/D2 regions.
Key Features: Germ tube negative yeast and sugar assimilation pattern. Common
saprophyte however cases of peritonitis and fungaemia have been reported.
Physiological Tests: + Positive, - Negative, v Variable, w Weak, s Slow, nd No Data
Germ Tube - L-Sorbose v L-Arabinose v D-Glucitol v
Fermentation Sucrose + D-Arabinose v α-M-D-glucoside
Glucose - Maltose v D-Ribose v D-Gluconate +
Galactose - Cellobiose v L-Rhamnose v DL-Lactate v
Sucrose - Trehalose + D-Glucosamine v myo-Inositol -
Maltose - Lactose - N-A-D-glucosamine - 2-K-D-gluconate nd
Lactose - Melibiose - Glycerol v D-Glucuronate nd
Trehalose - Raffinose + Erythritol v Nitrate -
Assimilation Melezitose v Ribitol v Urease +
Glucose + Soluble Starch - Galactitol v 0.1% Cycloheximide -
Galactose v D-Xylose + D-Mannitol v Growth at 40 O C +
Antifungal Susceptibility: R. mucilaginosa (Diekema et al. 2005, Australian
National data); MIC µg/mL. Note: Rhodotorula species are intrinsically resistant to
azoles and echinocandins (Arendrup et al. 2014).
No. 64
AmB 39 4 4 5 25 1
FLU 39 39
VORI 37 2 3 6 11 10 4 1
POSA 37 1 3 8 17 2 2 4
ITRA 39 3 8 15 4 1 2 6
5FC 39 1 14 12 11 1