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Parassitologia 50: 77-79, 2008
The genus Malassezia: old facts and new concepts
J. Guillot 1, S. Hadina 2, E. Guého 3
1 INRA, AFSSA, ENVA, UMR 956, Ecole Nationale Vétérinaire d’Alfort, Maisons-Alfort, France; 2 Faculty of Veterinary
Medicine, University of Zagreb, Croatia; 3 Mauves sur Huisne, France
Abstract. Lipophilic yeasts are being considered as major opportunistic pathogens for a very long time.
Most of the yeasts show an absolute requirement for long fatty acid chains and specific procedures are
required for their isolation, conservation and identification. For that reason, the history of the nomenclature
used for the Malassezia genus is quite complex. Before 1996, only 3 species were recognized: Malassezia
furfur, M. pachydermatis and M. sympodialis. To date, the genus is composed of one non lipid-dependent
species (M. pachydermatis) and 12 lipid-dependent species. No doubt that additional new taxa will be
described in close future. Very recently the genome and secretory proteome of two Malassezia species was
described. This analysis demonstrated the presence of multiple secreted lipases to aid in harvesting host
lipids. It also revealed the presence of mating-type genes, providing an indication that Malassezia yeasts
may be capable of sex.
Key words: Malassezia, yeast, species, taxonomy, nomenclature
For more than 150 years, Malassezia yeasts have been
associated with skin diseases in humans and different
animal species. In recent years these fungi have also
been recognized as opportunistic pathogens causing
invasive infections in neonates.
Malassezia species have an affinity for lipids as substrates
and the term “lipophilic yeasts” has frequently
been used to characterize the genus. In fact, most of the
species show an absolute requirement for long fatty
acid chains and they are therefore seldom isolated in
the laboratory unless specific nutrients are provided in
the medium. The cells of all Malassezia species have in
common a monopolar and repetitive budding process
(leaving a thick scar on the mother cell) and a multilayered
cell wall with a corrugate innermost layer to which
corresponds a helicoidal translucent band. However
specific identification is not straightforward and history
of the nomenclature used for the Malassezia genus
is quite complex.
First descriptions
Malassezia yeasts were first recognized in 1846 when
Eichstedt realized the fungal nature of pityriasis versicolor,
a very common skin disease in humans. He
reported the presence of round yeasts and filaments in
scales of patients. The agent of pityriasis versicolor was
named Malassezia furfur by Baillon in 1889. In subsequent
years, lipophilic yeasts alone were observed by
many authors in samples of healthy skin and also in
conditions such as seborrheic dermatitis and pityriasis
capitis (dandruff). In 1904, Sabouraud assigned these
yeasts to the genus Pityrosporum. In 1913, Castellani
Correspondence: Jacques Guillot
Ecole Nationale Vétérinaire d’Alfort, Maisons-Alfort, France,
Tel 33 1 43 96 71 57; Fax 01 43 96 71 90
e-mail: jguillot@vet-alfort.fr
and Chalmers described the species P. ovale by
acknowledging an earlier name, Saccharomyces ovalis
Bizzozero 1884 (Slooff 1970). In 1951, Gordon
described a new Pityrosporum species, P.orbiculare.
Although this was associated with healthy skin, he also
identified the yeast with the organism M. furfur, the
agent of pityriasis versicolor (Gordon 1951).
Weidman provided the first description of lipophilic
yeasts from an animal species in 1925. He isolated
yeasts with a similar morphology to that of P. ovale
from skin lesions of an Indian rhinoceros. Weidman
described the new species P. pachydermatis. In 1955,
Gustafson isolated the same type of yeast from otitis
externa in dogs. Gustafson wrongly concluded from
early descriptions that the yeasts recovered from rhinoceros
skin grew poorly and were very difficult to
maintain. As a consequence, Gustafson created the
new species P. canis. The synonymy between P. pachydermatis
and P. canis was proved by Guillot & Guého
in 1996.
The need to assign all lipophilic yeasts to a single genus
was finally recognized by taxonomists. The genus
Malassezia created by Baillon predates Sabouraud’s
Pityrosporum. As a consequence, the species mentioned
above were all assigned to the genus Malassezia
in recent reviews (Ahearn and Simmons 1998, de Hoog
et al. 2000).
An increasing number of species
Before 1996, only 3 species were recognized within the
genus Malassezia: M. furfur (Robin) Baillon 1889, M.
pachydermatis (Weidman) Dodge 1935 and M. sympodialis
Simmons and Guého 1990. In addition to the
above species, stable variants identified by morphological
and immunological features had been documented
in the literature (Midgley 1989, Cunningham et al.
1990). However, these variants were proposed without
a valid description or a type specimen. Genetic studies,