World of Dermatophytes: A Pictorial Prov Lab Home

Microsporum audouinii [E. floccosum] [M. canis]

Microsporum audouinii colonial morphology on PYE
Microsporum audouinii PDA Reverse Side
Microsporum audouinii phase contrast microscopy
Microsporum audouinii biochemicals
Colonial Morphology
Microscopic Morphology
Phase Contrast
Biochemical Reactions:
BCP, SDA and Urease
  • Growth rate: slow
  • Texture: downy to silky, flat, spreading, dense
  • Thallus color: white to light tan
  • Reverse: peach or salmon on PDA, yellowish brown to red brown on SDA
  • rare club-shaped microconidia
  • rare deformed, spindle shaped macroconidia, longer and smoother than M. canis
  • pectinate hyphae
  • terminal or intercalary chlamydospores
  • BCP: profuse, alkaline, hydrolysis
  • Urease: negative or positive
  • Hair perforation: negative
  • Rice: poor growth, brown pigment, no conidia
  • Vitamin requirement: none, some strains enhanced by thiamine
Compare to and
differentiate from:

Etiology & Ecology
  • anthrophilic
  • worldwide, rare except in Africa and Asia
  • scalp and body
  • once caused epidemic tinea capitis in prepubescent children, now rare
  • also spread by guinea pigs and dogs