[Ecology of opportunistic fungi].

As most of the pathogenic fungi, opportunistic fungi have a saprophytic life in the soil. The knowledge of their life in natural conditions may allow to avoid their proliferation in the vicinity of man. Examples of ecology were taken among Aspergilli and mycetoma-inducing fungi. The ecology of these fungi was studied in Senegal-Mauritania where mycetoma is fairly frequent and well studied. Cultures of L. senegalensis and L. tompkinsii were very often isolated from dry thorns of acacias or other thorn trees. M. mycetomi, the most frequent mycetoma-inducing fungus, was very difficult to culture from wood or soil specimens. A special selective sulphide medium had to be used. Some strains of M. mycetomi were isolated from specimens taken off the surface of termitaria.