The objective of this study was to determine if thermophilic fungi exist in the mycoflora of man and in the aeroflora of his environment.Humicola lanuginosa andHumicola grisea were isolated from 5 of 55 samples of outside air. Three thousand cultures were taken from the nasal mucosae, skin surfaces and recta of 570 children. Cultures were incubated at 50°C. Thermophilic fungi were isolated from 6 of 287 children receiving immunosuppressive therapy for malignancies and from 1 of 283 normal children.H. lanuginosa was recovered from the skin of one, the rectum of one and the nasal mucosae of three patients.Mucor pusillus was isolated from the nasopharynges of two patients.
Further studies are now indicated to determine the pathogenicity of these organisms with respect to tissue invasive disease, antigenicity and metabolite toxicity.