Microsporum audouinii An anthropophilic fungus causing non-inflammatory infections of scalp and skin especially in children. Once the cause of epidemics of tinea capitis in Europe and North America but is becoming less frequent. Invaded hairs show an ectothrix infection and usually fluoresce a bright greenish-yellow under Wood's ultra-violet light. Distribution: World-wide. Key Features: Absence of conidia and poor or absence of growth on polished rice grains. Text slide.

156. Typical M. audouinii infection of scalp showing hair loss and scaling.

157. Chronic M. audouinii scalp infection of 6 years duration showing minimal hair loss and scaling.

158. Colony of M. audouinii on mycobiotic agar showing a flat, spreading, downy white surface with a salmon or peach-pink reverse pigment. 158

159. Colony of M. audouinii on mycobiotic agar showing a flat, spreading, downy white surface with a salmon or peach-pink reverse pigment. 159

160. Microscopy morphology of M 160. Microscopy morphology of M. audouinii showing a thick-walled intercalary chlamydoconidium. Note macroconidia and microconidia are only rarely produced. 160

161. Nutritional requirements. Growth of M 161. Nutritional requirements. Growth of M. audouinii is enhanced by the presence of thiamine (Trichophyton agars No.1 and No.4, Difco). 161

162. Growth of M. audouinii on polished rice grains is very poor or absent, usually being visible only as a brown discoloration. This is one of the features, which distinguish M. audouinii from M. canis. 162