DESCRIPTIONS OF MEDICAL FUNGI

154
Descriptions of Medical Fungi
The genus Phialophora contains more than 40 species, most are saprophytes
commonly found in soil or on decaying wood. Some human pathogens with phialidic
conidiogenesis previously assigned to Phialophora have been moved to other genera,
namely, Phaeoacremonium and Pleurostomophora. P. verrucosa, P. americana, P.
bubakii, P. europaea and P. reptans remain of medical interest (Revankar and Sutton
2010). Both P. verrucosa and P. americana produce their conidia from phialides with
conspicuous darkened collarettes, however sequencing has demonstrated a close
relatedness, suggesting that these species may be synonymous (de Hoog et al. 1999).
P. verrucosa is primarily an agent of chromoblastomycosis although other reported
infections include endocarditis, keratitis, and osteomyelitis.
RG-2 organism.
Phialophora verrucosa Medlar
Morphological Description: Colonies (SDA) are slow growing, initially dome-shaped,
later becoming flat, suede-like and olivaceous to black in colour. Phialides are flaskshaped
or elliptical with distinctive funnel-shaped, darkly pigmented collarettes. Conidia
are ellipsoidal, smooth-walled, hyaline, mostly 3.0-5.0 x 1.5-3.0 μm, and aggregate in
slimy heads at the apices of the phialide.
Key Features: Characteristic flask-shaped phialides with distinctive funnel-shaped,
darkly pigmented collarettes.
Molecular Identification: ITS sequencing recommended (de Hoog et al. 1999).
References: Ellis (1971), McGinnis (1978a, 1980), Domsch et al. (1980), de Hoog et
al. (1999, 2000, 2015), Revankar and Sutton (2010).
20 µm
20 µm
Phialophora verrucosa phialides and conidia.