Stemphylium sp.

Colonies are rapid growing, brown to olivaceous-black or greyish and suede-like to floccose.  Microscopically, solitary, darkly pigmented, terminal, multicellular conidia (dictyoconidia) are formed on a distinctive conidiophore with a darker terminal swelling. Note the conidiophore proliferates percurrently through the scar where the terminal conidium (poroconidium) was formed.  Conidia are pale to mid-brown, oblong, rounded at the ends, ellipsoidal, obclavate or subspherical and are smooth or in part verrucose. Stemphylium should not be confused with Ulocladium which produces similar dictyoconidia from a sympodial conidiophore, not from a percurrent conidiogenous cell as in Stemphylium.

Conidiophores and conidia of Stemphylium sp.

Clinical significance:

Most species are plant pathogens with occasional isolates from soil, they are rarely seen in the clinical laboratory.

Mycosis: Phaeohyphomycosis

Further reading:

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

McGinnis, M.R. 1980. Laboratory handbook of medical mycology. Academic Press, London, UK.