DESCRIPTIONS OF MEDICAL FUNGI

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Descriptions of Medical Fungi
RG-1 organisms.
Malassezia Baillon
Morphological Description: On media like modified Dixon’s agar, colonies are cream
to yellowish, smooth or lightly wrinkled, glistening or dull, and with the margin being
either entire or lobate. Malassezia is characterised by globose, oblong-ellipsoidal to
cylindrical yeast cells. Reproduction is by budding on a broad base and from the same
site at one pole (unipolar).
Molecular Identification: ITS and D1/D2 sequencing may be used for accurate
species identification (de Hoog et al. 2015).
MALDI-TOF MS: Capable of identifying all 14 Malassezia species in concordance with
those of ITS sequence analyses (Kolecka et al. 2014).
Identification criteria for the differentiation of Malassezia species (de Hoog et. al. 2015).
+ Positive, - Negative, v Variable, w Weak, s Slow, nd No Data
Species Buds SDA 40 O C
Cremophor
EL
Tween
80
Tween
60
Tween
40
Tween
20
Esculine
M. caprae narrow - - - + + + + + +
M. couiculi narrow - + - - - - - nd +
M. dermatis wide - + nd + + + + nd +
M. equina narrow - - - + + + + + +
M. furfur wide - + + + + + w +
M. globosa narrow - - - - - - - +
M. japonica wide - - nd - + w - nd +
M. nana narrow - v nd w + + v nd +
M. obtusa wide - - - - - - + +
M. pachydermatis wide + + -,w + + -,w v v
M. restricta narrow - - - - - - - -
M. slooffiae wide - + - +,w + + - +
M. sympodialis narrow - + -,w + + + + + +
M. yamatoensis wide - - nd + + + + nd +
Antifungal Susceptibility: Very limited data available. Special growth conditions
are needed for antifungal susceptibility testing; data from Nakamura et al. (2000),
Velegraki et al. (2004) and Miranda et al. (2007); MIC µg/mL.
MIC µg/mL
MIC µg/mL
Antifungal Range MIC Antifungal
90
Range MIC 90
FLU 0.125->64 4 (8) AmB 0.03-16 1 (8)
Catalase
References: Guillot and Gueho (1995), Gueho et al. (1996), Guillot et al. (1996, 2000),
Boekhout et al. (2010), Cafarchia et al. (2011), de Hoog et al. (2015).
ITRA 0.03-16 0.125 VORI 0.03-16 0.125 (1)
KETO 0.03-4 0.25 POSA 0.03-32 0.125 (2)
Note: There is no standardised method and results are often variable, therefore
susceptibility testing for guiding treatment is not recommended.