DESCRIPTIONS OF MEDICAL FUNGI

152
Descriptions of Medical Fungi
Phaeoacremonium parasiticum (Ajello et al.) W. Gams et al.
Synonymy: Phialophora parasiticum Ajello, Gerog & Wang.
The genus Phaeoacremonium initially accommodated isolates with features similar to
those seen in both Acremonium and Phialophora. It differs from the former by having
pigmented hyphae and conidiophores and from the latter by having indistinct collarettes
and warty conidiogenous cells (Revankar and Sutton, 2010).
Phaeoacremonium currently consists of 46 species with P. parasiticum and P. krajdenii
recognised as the predominant species associated with human infections (Mostert
et al. 2005). Other species have also been isolated from clinical cases i.e. P. alvesii,
P. amstelodamense, P. griseorubrum, P. minimum, P. rubrigenum, P. tardicrescens,
and P. venezuelense. Infections caused by P. parasiticum include subcutaneous
abscesses, thorn-induced arthritis, and disseminated infection (Revankar and Sutton,
2010, Gramaje et al. 2015).
RG-2 organism.
Morphological Description: Cultures usually slow growing, suede-like with radial
furrows, initially whitish-grey becoming olivaceous-grey with age. Hyphae hyaline, later
becoming brown and some becoming rough-walled. Phialides are brown, thick-walled,
slender, acular to cylindrical slightly tapering towards the tip, 15-50 μm long, often
proliferating, with small, funnel-shaped collarettes. Conidia, often in balls, are hyaline,
thin-walled, cylindrical to sausage-shaped, 3-6 x 1-2 μm, later inflating. Maximum
growth temperature 40°C.
Molecular Identification: ITS and β-tubulin sequencing (Mostert et al. 2006, Gramaje
et al. 2015).
Key Features: The identification of the different Phaeoacremonium species can be
done by combining cultural, morphological and sequence data (Mostert et al. 2006,
Gramaje et al. 2015).
References: de Hoog et al. (2000, 2015), Revankar and Sutton (2010), Mostert et al.
(2005, 2006), Gramaje et al. (2015), Badali et al. (2015).
10 µm
a
b
Phaeoacremonium parasiticum (a) colony and (b) a phialide
with a small, funnel-shaped collarette.