DESCRIPTIONS OF MEDICAL FUNGI

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Descriptions of Medical Fungi
The genus Pithomyces contains about 50 species commonly isolated from a wide range
of plant material, also from air, soil, hay, sawn timber and ceiling plaster. Pithomyces
chartarum has long been reported as causing facial eczema in sheep. However, recent
molecular studies have identified at least two additional species P. sacchari and P.
maydicus (de Cunha et al. 2014). Most human isolates are recovered from skin, nail,
respiratory and sinus specimens.
RG-1 organism.
Pithomyces chartarum (Berk. & M.A. Curtis) M.B. Ellis
Morphological Description: Colonies are fast growing, suede-like to downy
and black. Conidiophores are pale olive, smooth or verrucose, 2.5-10 x 2-3.5 µm.
Conidiogenous cells integrated, intercalary or terminal, indeterminate, with one to two
loci of similar width in the conidiogenous cells. Conidia are muriform, medium to dark
brown, echinulate to verrucose, three-(some up to five)-euseptate, slightly constricted
at the septa, with one or both median cells divided by longitudinal septa, thick-walled,
broadly ellipsoidal, apex obtuse, base truncate and characteristically with part of the
conidiogenous cell remaining attached as a small pedicel, 18-29 x 10-17 µm.
Key Features: Dematiaceous hyphomycete with multicelled conidia produced on
small peg-like branches of the vegetative hyphae.
Molecular Identification: ITS and D1/D2 sequencing recommended (de Cunha et al.
2014).
References: Ellis (1971, 1976), Domsch et al. (1980), Rippon (1988), de Hoog et al.
(2000, 2015), de Cunha et al. (2014).
15 µm
Pithomyces chartarum conidiophores and conidia.