Meyerozyma guilliermondii

Synonymy: 
Candida guilliermondii.

Meyerozyma guilliermondii has been isolated from numerous human infections, mostly of cutaneous origin.

It is also found on normal skin and in sea water, faeces of animals, fig wasps, buttermilk, leather, fish and beer.

RG-1 organism.

Culture: 
White to cream-coloured smooth, glabrous, yeast-like colonies.

Microscopy: 
Spherical to subspherical budding yeast-like cells or blastoconidia, 2.0-4.0 x 3.0-6.5 µm.

India ink preparation: 
Negative - no capsules present.

Dalmau plate culture: 
Branched pseudohyphae with dense verticils of blastoconidia.

Molecular identification:
ITS sequencing recommended.

MALDI-TOF MS: 
Able to accurately identify this species.

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 v
Glucose + Maltose + D-Ribose + D-Gluconate v
Galactose v Cellobiose v L-Rhamnose v DL-Lactate v
Sucrose + Trehalose + D-Glucosamime + myo-Inositol -
Maltose - Lactose - N-A-D-glucosamine + 2-K-D-Gluconate +
Lactose - Melibiose v Glycerol + D-Glucuronate nd
Trehalose + Raffinose + Erythritol - Nitrate -
Assimilation   Melezitose v Ribitol + Urease -
Glucose + Soluble Starch - Galactitol v 0.1% Cycloheximide v
Galactose + D-Xylose + D-Mannitol v Growth at 37C v

Key features: 
Germ tube negative yeast and sugar assimilation pattern.

Antifungal susceptibility: Meyerozyma guilliermondii (Diekema et al. 2009; Pfaller et al., 2013a and Australian national data); MIC µg/mL.

Antifungal No ≤0.016 0.03 0.06 0.125 0.25 0.5 1 2 4 8 16 32 ≥64
AMB 234 2 2 9 72 77 49 14 2 1 6      
FLU 235         1 7 17 93 79 19 9 3 7
ISAV 29   1 1 6 6 9 1 3 2        
VORI 241 14 27 103 67 16 3 2 3     6    
POSA 238 1 11 15 55 93 48 5 4     6    
ITRA 60       10 11 32 5 1     1    
ANID 164 1   4 8 6 13 64 59 8 1      
MICA 153 3 1 4 11 20 62 37 13   1 1    
5FC 60   8 47 3 1 1 1            

Back to Yeast-like Fungi