Trichophyton

1
Trichophyton

• The thiamin requirement test
• T. tonsorans grows poorly on a chemically defined
  medium poor in thiamin (Trichophyton Agar 1) and
  very well on a thiamin enriched medium
  (Trichophyton Agar 4)
• T. rubrum and T. mentagrophytes grow equally well
  on both media no elevated thiamin requirement

2
Nutritional Requirement of Trichophyton species
3
Trichophyton

• Microscopic exam of cultures
• Most Trichophyton species produce numerous
  globose to pyriform microconidia (not septate) in
  two primary arrangements
• Along the hyphae likes birds on a telephone wire
  (en thyrse) or
• In large clusters (en grappe)

4
Trichophyton

• Microscopic exam of cultures
• Microconidia of T. tonsorans tend to vary in size
• Macroconidia are scarce in this genus
• If present they are pencil or club shaped
  (clavate) and multiseptate with thin smooth walls

5
Conidia of Trichophyton
Typical macroconidia and en grappe microconidia
en thyrse microconidia
6
Differential Characteristics of Selected
Trichophyton
T. rubrum T. mentagrophytes T.
tonsorans In vitro Hair
?
? Baiting Good Growth on Trich.

? Agar 1 Red colony on
? ? CMD or PDA
Urease ?
? (Red Urea Agar ?3d)

7
Epidermophyton floccosum

• The genus Epidermophyton is comprised of only one
  species E. floccosum
• Colonies of E. floccosum are typically fluffy and
  have an off-yellow color described as khaki green

8
Epidermophyton floccosum
9
Epidermophyton floccosum

• Diagnostic Microscopic features
• Club shaped smooth thin-walled macroconidia
• Can have multiple macroconidia emanating from one
  conidiophore
• E. floccosum produces no microconidia

10
E. floccosum Conidia