DESCRIPTIONS OF MEDICAL FUNGI

Descriptions of Medical Fungi 83
Synonymy: Epicoccum purpurascens Ehrenb. ex Schlecht.
Epicoccum nigrum is a cosmopolitan saprophyte of worldwide distribution which is
occasionally isolated as a contaminant from clinical specimens like skin.
RG-1 organism.
Epicoccum nigrum Link
Morphological Description: Colonies are fast growing, suede-like to downy, with a
strong yellow to orange-brown diffusible pigment. When sporulating, numerous black
sporodochia (aggregates of conidiophores) are visible. Conidia are formed singly on
densely compacted, non-specialised, determinant, slightly pigmented conidiophores.
Conidia are globose to pyriform, mostly 15-25 µm diameter with a funnel-shaped base
and broad attachment scar, often seceding with a protuberant basal cell; i.e. aleuric or
rhexolytic dehiscence of conidia. Conidia become multicellular (dictyoconidia), darkly
pigmented and have a verrucose external surface.
Key Features: Dematiaceous hyphomycete producing darkly pigmented, large globose
to pyriform, verrucose dictyoconidia on a sporodochium.
References: Ellis (1971), Domsch et al. (1980), McGinnis (1980), Samson et al. (1995).
a
b
15 µm
Epicoccum nigrum (a) culture and (b) conidia.