Madurella mycetomatis

Colonies are slow growing, flat and leathery at first, white to yellow to yellowish-brown, becoming brownish, folded and heaped with age and the formation of aerial mycelia. A brown diffusable pigment is characteristically produced in primary cultures. Although most cultures are sterile, two types of conidiation have been observed, the first being flask-shaped phialides that bear rounded conidia, the second being simple or branched conidiophores bearing pyriform conidia (3-5 um) with truncated bases. The optimum temperature for growth of this mould is 37C.  RG-2 organism.

Culture of Madurella mycetomatis showing the typical brown diffusable pigment in the agar.

Phialides of M. mycetomatis (rarely seen as most isolates are sterile).

M. mycetomatis can be distinguished from Madurella grisea by growth at 37C and its inability to assimilate sucrose.

MIC data is limited.  Antifungal susceptibility testing of individual strains is recommended.

Clinical significance:

The genus Madurella is based on tissue morphology (mycetoma with black grains) and the formation of sterile cultures on mycological media and is in need of revision. Both M. mycetomatis and M. grisea have been isolated from soil and are one of the major causative agents of mycetoma.

Mycosis: Mycetoma

Further reading:

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.