Mycology Practical

Trichophyton rubrum

Defining Characteristic

• Microconidia: Club shaped, singularly on hyphae

Disease Association

• Skin and nail infection

• Causes ectothrix hair invasion

Susceptible Population

• People on immunosuppressive therapy

  • May cause subcutaneous nodules and/or abscesses

Trichophyton mentagrophytes

Defining Characteristic

• Macroconidia — Pencil-shaped, thin-walled

• Microconidia — Round, in grape-like clusters

Disease Association

• Athlete’s foot

Susceptible Population

• College students, athletes

Trichophyton tonsurans

Defining Characteristic

• Macroconidia — Rare, smooth-walled, club-shaped

• Microconidia — Great size and shape variation

• Chlamydoconidium (balloons) and racquet hyphae

Disease Association

• Scalp ringworm

• Black dot tinea captis

Susceptible Population

• Children

Aspergillus niger

Defining Characteristic

• Conidiophores — Long, smooth

• Phialides — Cover entire vesicle. Form “radiate” head

Disease Association

• Aspergillosis

Susceptible Population

• Debilitated people

Conidiophore = something that holds conidium (spore)

Phialides = flask-like structure

** The stem is much more thicker than A. fumigates

Aspergillus fumigatus

Defining Characteristic

• Conidiophores — Short, smooth

• Phialides — On upper two-thirds of vesicle. Parallel to conidiophore

Disease Association

• Aspergillosis

Susceptible Population

• Immunocompromised

Penicillium

Defining Characteristic

• Flask-shaped phialides

• Chains of phialoconidia in brush-like patterns

Disease Association

• Keratomycosis, penicilliosis, and ear and nail infections

Susceptible Population

• Immunocompromised

Rhizopus

Defining Characteristic

• Rhizoids at base of sporangiophore

Disease Association

• Zygomycosis

• Otomycosis

Susceptible Population

• Immunocompromised

Mucor

Defining Characteristic

• Branched or unbranched sporangiophores

• No rhizoids

Disease Association

• Zygomycosis

• Otomycosis

• Allergies

Susceptible Population

• Immunocompromised

Scopulariopsis

Defining Characteristic

• Lemon-shaped annelloconidia that become spiny

• Septate hyphae

Disease Association

• Keratomycosis

Susceptible Population

• Immunocompromised

Scedosporium apiospermum

Defining Characteristic

• Single or small clustered, oval annelloconidia

• Long or short annellophores

Disease Association

• Mycetoma

Susceptible Population

• Immunocompromised

Alternaria

Defining Characteristic

• Dark hyphae + conidia

• Tapered ends

• Chained poroconidia w/ horizontal + vertical conidia

Disease Association

• Keratomycosis, skin + nasal septum infections, osteomyelitis, pulmonary disease

Susceptible Population

• Immunocompromised

Fusarium

Defining Characteristic

• Conidiophores — single or branching

• Microconidia — single-celled in balls

• Macroconidia — banana shaped

Disease Association

• Keratomycosis, skin lesions, disseminated infections

Susceptible Population

• Burn patients, immunocompromised

Sporothrix schenckii

Defining Characteristic

• (Must use oil immersion)

• Conidia in rosette form

Disease Association

• Sporotrichosis

Susceptible Population

• Rose gardeners

Histoplasma capsultaum

Defining Characteristic

• Smooth-walled or tuberculate macroconidia

• Tear drop microconidia

Disease Association

• Histoplasmosis

Susceptible Population

• Immunocompromised

• Ohio