Aspergillus nidulans. Coloured scanning electron micrograph of the fungus Aspergillus nidulans, cause of aspergillosis and mycetoma. Here, fungal threads are swollen into conidiophores (fruiting bodies, brown) which bear chains of conidia (spores, red) at the tip. A.nidulans produces the toxin sterigmatocysin" which may lead to food contamination. It also causes allergic aspergillosis, a hypersensitive lung reaction in asthmatics and those with lowered resistance, provoked by repeated inhalation of the spores. Mycetoma (Madura foot) may result when this fungus infects subcutaneous tissue, bone and skin. Magnification: x1,300 at 6x7cm size. x4,400 at 8x10""