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Superficial Fungal Infections:Dermatophytes Part 1
Glenn D. Roberts, PhD
Division of Clinical Microbiology
Department of Laboratory Medicine & Pathology
Mayo Clinic
Rochester, Minnesota
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Disclosures
None
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Selection of Clinical Specimens
Normal Host Hair
Skin
Nails
Immunocompromised host
Potentially any source
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Superficial Fungal Infections: Dermatophytes Part 1
Microbiology
Trichophyton
Characterized by macroconidia that are elongated,
pencil to cigar-shaped, smooth-walled, multiseptate,and thin-walled
In general, microconidia predominate in most cultures
They may be arranged in clusters, produced singly alonghyphae, or hardly sporulate at all
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Genus Trichophyton
Superficial Fungal Infections: Dermatophytes Part 1
Microbiology
Epidermophyton
Produces only large, multiseptate, smooth-walled,and club-shaped macroconidia
Microsporum
Characterized by large, multiseptate, rough-walled,and spindle-shaped macroconidia
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Superficial Fungal Infections: Dermatophytes Part 1
Genus Epidermophyton
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Superficial Fungal Infections: Dermatophytes Part 1
Genus Microsporum
Superficial Fungal Infections: Dermatophytes Part 1
Common Dermatophytes Foundin North America
Trichophyton rubrum T mentagrophytes
T tonsurans
T verrucosum
Microsporum canis M audouinii
Epidermophytonfloccosum
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Superficial Fungal Infections: Dermatophytes Part 1
Ecology
Anthropophilic
Trichophyton mentagrophytes
Trichophyton rubrum
Trichophyton tonsurans
Epidermophyton floccosum
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Superficial Fungal Infections: Dermatophytes Part 1
Direct Microscopic Examination
Septate hyaline hyphae
Arthroconidia
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2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
KOH Preparation
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Superficial Fungal Infections: Dermatophytes Part 1
KOH Preparation
Superficial Fungal Infections: Dermatophytes Part 1
Common Clinical Presentations
Tinea pedis: infection of the feet
Primarily involving the soles and toe webs, seenin areas between the third and fifth toes
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2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Tinea Pedis
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Superficial Fungal Infections: Dermatophytes Part 1
Severe Tinea Pedis
Superficial Fungal Infections: Dermatophytes Part 1
Common Clinical Presentation
Tinea cruris: infection of the groin
Including the perineum and perianal region
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2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Tinea Cruris
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Superficial Fungal Infections: Dermatophytes Part 1
Common Clinical Presentation
Tinea corporis: infection of the smooth skinof the trunk and extremities
Exclusive of the face, foot, groin, hands, or scalp area
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2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Tinea Corporis
Superficial Fungal Infections: Dermatophytes Part 1
Common Clinical Presentation
Tinea capitis: infection of the scalp,eyebrows, and eyelashes
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Superficial Fungal Infections: Dermatophytes Part 1
Tinea Capitis
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Onychomycosis:nails and surroundingtissues may be infected by a number of fungiincluding Aspergillus, Fusarium, and others
Common Clinical Presentation
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Superficial Fungal Infections: Dermatophytes Part 1
Onychomycosis
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1
Superficial Fungal Infections: Dermatophytes Part 1
Microbiology
Tinea pedis
Trichophyton rubrum
Trichophyton mentagrophytes
Epidermophyton floccosum
Tinea cruris
Epidermophyton floccosum
Trichophyton rubrum
Trichophyton mentagrophytes
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Microbiology
Tinea corporis
Trichophyton rubrum
Trichophyton mentagrophytes
Microsporum canis
Tinea capitis
Trichophyton tonsurans
Microsporum canis
Microsporum audouini
Trichophyton violaceum
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Superficial Fungal Infections: Dermatophytes Part 1
Epidermophyton floccosum
Microscopic IdentificationFrom Mycosel or Cornmeal Agars
Large, smooth-walled, club-
shaped conidia arranged singlyor in clusters of 2 or 3
Colony khaki colored with white areas
Epidermophyton floccosum
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Superficial Fungal Infections: Dermatophytes Part 1
Microscopic Morphologic Features
Epidermophyton floccosum
Hyphae are hyaline, septate, and contain
numerous chlamydoconidia
Macroconidia are blunt, club-shaped,smooth-walled, multicelled
Attached singly or in groups of 2 or 3
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Epidermophyton floccosum
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Epidermophyton floccosum
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Superficial Fungal Infections: Dermatophytes Part 1
Cultural Features
Epidermophyton floccosum
Colonies are pale olive-green or khaki; some may
be white in color; most are folded and velvety
White sterile hyphae cover the colonies after2 to 3 weeks of incubation
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
Superficial Fungal Infections: Dermatophytes Part 1
Epidermophyton floccosum
2012 Mayo Foundationfor Medical Educationand Research. All rights reserved.
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