Sepedonium

Sepedonium species are common soil fungi and parasites of fleshy fungi, however Yogo et al. (2014) reported an intra-abdominal infection in an immunosuppressed patient. Sepedonium species closely resemble Histoplasma capsulatum

Note: For laboratory safety, culture identification to exclude Histoplasma capsulatum should be performed by either exoantigen test or DNA sequencing.

RG-1 organism.

Sepedonium conidia

Sepedonium spp. showing large, globose, thick-walled, one-celled, verrucose, terminal conidia.

Morphological description: 
Colonies are moderately fast growing, usually white to golden yellow, suede-like to downy, becoming fluffy with age. Conidiophores are hyaline and non-specialised, resembling short branches of the vegetative hyphae. Conidia are terminal, solitary, or in clusters, one-celled, globose to ovoid, 7-17 µm, hyaline to amber, smooth to verrucose and usually with a thick wall.

Key features: 
Hyphomycete, producing large, thick-walled, one-celled, verrucose, globose, terminal conidia from non-specialised conidiophores, resembling the macroconidia seen in Histoplasma capsulatum.

Molecular identification: 
I
TS and D1/D2 sequencing may be used for accurate species identification (Halliday et al. 2015).

References: 
McGinnis (1980), Rippon (1988), Yogo et al. (2014).