ABSTRACT
The soil constitutes a major reservoir of fungi pathogenic to humans and animals (Ajello, 1956). In the soil the fungus decays organic matter derived from the dead bodies of animals and plants and may grow and sporulate strongly. Mycopathogenic species of Aspergillus and members of the Mucorales (e.g. Absidia, Mucor, Rhizopus, see Figure 5.3) can usually be isolated from samples of topsoil and compost. Such fungi are essentially saprobic, acting as opportunistic (adventitious) mycopathogens, mainly infecting those who are already seriously ill and immunocompromised, or perhaps entering and infecting the bodies of otherwise healthy people through wounds. Some potential mycopathogens may also live saprobically as commensal organisms on the skin and mucocutaneous surfaces where they appear to constitute part of the normal microflora of the human body and cause no detectable damage. For example, species of Aspergillus may be isolated from the external auditory meatus and alveoli, and Candida from the skin of the hands and mucocutaneous surfaces of apparently healthy individuals.
