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,b 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 243 2 2 9 72 80 53 16 2 1 6      
FLU 244         1 7 17 96 83 21 9 3 7
ISAV 33   1 2 8 6 10 1 3 2        
VORI 250 14 28 107 70 17 3 2 3     6    
POSA 247 1 12 19 58 94 48 5 4     6    
ITRA 69       11 16 35 5 1     1    
ANID 172 1   4 8 6 16 69 59 8 1      
MICA 162 3 1 4 11 23 68 37 13   1 1    
5FC 67   8 54 2 1 1 1            

References

  • Diekema, D.J., Messer, S.A., Boyken, L.B., et al. (2009) In vitro activity of seven systemically active antifungal agents against a large global collection of rare Candida species as determined by CLSI broth microdilution methods. Journal of Clinical Microbiology, 47, 3170-3177.
  • Kurtzman, C.P. (2011) Chapter 47, Meyerozyma Kurtzman & M. Suzuki (2010), in Kurtzman, C.P., Fell, J.W. and Boekhout, T. (eds), The Yeasts, a Taxonomic Study, 5th edition, Elsevier B.V., pp. 621-641.
  • Pfaller, M.A., Messer, S.A., Rhomberg, P.R., et al. (2013a) In vitro activities of isavuconazole and comparator antifungal agents tested against a global collection of opportunistic yeasts and molds. Journal of Clinical Microbiology, 51, 2608-2616.
  • Pfaller, M.A., Messer, S.A., Woosley, L.N., et al. (2013b) Echinocandin and triazole antifungal susceptibility profiles for clinical opportunistic yeast and mould isolates collected from 2010 to 2011: Application of new CLSI clinical breakpoints and epidemiological cutoff values for characterization of geographic and temporal trends of antifungal resistance. Journal of Clinical Microbiology, 51, 2571-2581.

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