Trichophyton soudanense

On Sabouraud's dextrose agar, colonies are slow-growing with a flat to folded, suede-like surface. Often there is a broad fringe of submerged growth. Surface mycelium and reverse pigment are characteristically a deep apricot-orange in colour. Microscopically, the hyphae often show reflexive or right-angle branching. Pyriform microconidia may occasionally be present and numerous chlamydoconidia are often found in older cultures.  RG-2 organism.

Culture of Trichophyton soudanense.

Reflex hyphae branching in T. soudanense.

Clinical significance:

Trichophyton soudanense is an anthropophilic fungus which is a frequent cause of tinea capitis in Africa. Invaded hairs show an endothrix infection but do not fluoresce under Wood's ultra-violet light. Distribution is mainly in Africa with occasional isolates from Europe, Brazil and U.S.A.

Mycosis: Dermatophytosis

Further reading:

Rebell, G., and D. Taplin. 1970. The Dermatophytes. 2nd. revised edition. University of Miami Press, Coral Gables, Florida. USA.

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