Mycology

What are the three main components of fungal structure mentioned in the source?

Cell wall, Cell membrane, and Ergosterol.

The cell wall of fungi is primarily composed of what substance?

Chitin.

What is the key sterol component of the fungal cell membrane?

Ergosterol.

Which fungus-like organism is noted for not having ergosterol in its cell membrane?

Pneumocystis.

Fungi can be classified based on morphology into which three groups?

Yeast, Moulds/Hyphae, and Dimorphic fungus.

Which fungal morphology consists of only buds?

Yeast (e.g., cryptococcus).

Which fungi are known to form both yeast-like buds and pseudohyphae?

Candida and Malassezia.

Dimorphic fungi exist as _ at 37°C.

yeast

Dimorphic fungi exist as _ at 22-25°C (cold temperatures).

mold (hyphae)

What is the mnemonic for remembering the dimorphic fungi?

Body Heat Probably Changes Shapes.

In the mnemonic 'Body Heat Probably Changes Shapes', what does 'B' stand for?

Blastomyces.

In the mnemonic 'Body Heat Probably Changes Shapes', what does 'H' stand for?

Histoplasma.

In the mnemonic 'Body Heat Probably Changes Shapes', what does 'P' stand for?

Penicillium Marneffei, paracoccidioidomycosis.

In the mnemonic 'Body Heat Probably Changes Shapes', what does 'C' stand for?

Coccidioidomycosis.

In the mnemonic 'Body Heat Probably Changes Shapes', what does 'S' stand for?

Sporothrix schenckii.

Which stain is used to visualize black hyphae in mycology?

Gomori methenamine silver (GMS).

Which stain is used to visualize pink hyphae in mycology?

Periodic acid-Schiff (PAS) stain.

Which stain is used to visualize Cryptococcus on a biopsy sample?

Mucicarmine stain.

Which stain is used to visualize Cryptococcus in a CSF sample?

India ink/Nigrosin.

Which stain gives a white appearance to fungal elements under fluorescence microscopy?

Calcofluor white.

What is the common culture medium used for fungi, abbreviated as SDA?

Sabouraud dextrose agar.

Which blue stain is commonly used for observing fungal culture morphology?

Lactophenol cotton blue (LPCB).

What is the typical pH of Sabouraud dextrose agar (SDA)?

pH 5.6.

What two antibiotics are typically included in SDA to inhibit bacterial growth?

Gentamicin and chloramphenicol.

What substance is added to Lactophenol cotton blue (LPCB) stain for hydration?

Glycerol.

Mycology divides fungal infections into what three main categories?

Superficial mycosis, Subcutaneous mycosis, and Deep mycosis/systemic mycosis.

Tinea versicolor is caused by what organism?

Malassezia furfur.

A patient with Tinea versicolor typically presents with what type of skin lesions?

Hypopigmented lesions.

The microscopic appearance of Malassezia furfur on a skin scraping is described as _.

'Spaghetti and meatballs' or 'banana and grapes'.

What chemical is used for digesting keratin during a skin scraping examination for fungi?

10% KOH (potassium hydroxide).

What special supplement is required in SDA to culture Malassezia furfur?

Olive oil.

What is the characteristic appearance of Malassezia furfur colonies on culture media?

Fried Egg appearance.

What are the topical treatment options for Tinea versicolor?

10% sulphur ointment or 1-2% imidazole cream.

What are the systemic treatment options for Tinea versicolor?

Itraconazole or Fluconazole.

Tinea Nigra is characterized by what clinical presentation?

Brown patches on the palm and soles.

What is the causative organism of Tinea Nigra?

Hortaea Werneckii.

A superficial mycosis affecting the hair shaft, known as Black piedra, is caused by _.

Piedraia hortae.

A superficial mycosis affecting the hair shaft, known as White piedra, is caused by _.

Trichosporon Beigelii (Bijli).

What is a primary treatment for both black and white piedra?

Topical imidazole and/or cutting/shaving the hair.

What is the common name for infections caused by dermatophytes?

Tinea or ringworm.

What is the mnemonic for the three genera of dermatophytes?

TME (Trichophyton, Microsporum, Epidermophyton).

An infection of the scalp by a dermatophyte is called _.

Tinea capitis.

A dermatophyte infection of the beard is called _.

Tinea barbae.

A dermatophyte infection of the face is called _.

Tinea faciei.

A soft, boggy swelling of the scalp due to a dermatophyte infection is known as a _.

Kerion.

A dermatophyte infection of the groin (jock itch) is called _.

Tinea cruris.

A dermatophyte infection of the nail bed is called _.

Tinea unguium.

A fungal infection of the trunk is called _.

Tinea Corporis.

A dermatophyte infection of the feet (athlete's foot) is called _.

Tinea pedis.

Which dermatophyte genus is characterized by pencil-shaped macroconidia and maximum microconidia?

Trichophyton.

Which dermatophyte genus is characterized by spindle-shaped macroconidia and moderate microconidia?

Microsporum.

Which dermatophyte genus is characterized by club-shaped macroconidia and minimum microconidia?

Epidermophyton.

Which dermatophyte genus infects skin, hair, and nails?

Trichophyton.

Which dermatophyte genus infects skin and hair?

Microsporum.

Which dermatophyte genus infects skin and nails?

Epidermophyton.

The Hair Perforation Test is used to differentiate which two fungi?

Trichophyton rubrum and T. mentagrophytes.

Which organism shows hair shaft erosion in the Hair Perforation Test?

T. mentagrophytes.

What is the drug of choice (DOC) for treating Tinea capitis?

Griseofulvin.

What is a Dermatophytid (Id) reaction?

Sterile lesions that appear away from the original fungal infection, likely due to fungal products.

What is the key difference between the causative organisms of Actinomycetoma and Eumycetoma?

Actinomycetoma is caused by filamentous bacteria, while Eumycetoma is caused by fungus.

Actinomycetoma typically produces _ granules.

red or yellow/white

Eumycetoma, caused by Madurella mycetomatis, typically produces _ granules.

brown (due to melanin)

What is the treatment for Actinomycetoma?

Cotrimoxazole with or without amikacin for 6-12 months.

What is the treatment for Eumycetoma if antifungal therapy fails?

Amputation.

The _ phenomenon, an antigen-antibody complex, is seen in sporothrix schenckii infections and actinomycetoma.

Splendore-hoeppli

What is the causative organism of Rhinosporidiosis?

Rhinosporidium seeberi.

Rhinosporidium seeberi is classified as what type of organism?

Aquatic parasite.

What is the gross appearance of a lesion caused by Rhinosporidiosis?

Strawberry nasal polyp.

Microscopically, what structures are seen inside the sporangia of Rhinosporidium seeberi?

Endospores.

What is a key characteristic of Rhinosporidium seeberi regarding laboratory growth?

It is a non-cultivable organism.

What is the primary treatment for Rhinosporidiosis?

Surgery.

Chromoblastomycosis is characterized by the presence of warty skin lesions and microscopic structures known as _.

Copper penny bodies (sclerotic/muriform/medlar bodies).

What is the common route of infection for Chromoblastomycosis?

Traumatic inoculation, such as from barefoot walking.

What are the primary treatments for Chromoblastomycosis?

Wide surgical resection, with laser reduction or Amphotericin B if needed.

Sporothrix is classified as a mycosis and is also a fungus.

subcutaneous; dimorphic

What is another name for Blastomycosis?

North American blastomycosis, Chicago disease, or Gilchrist disease.

What is the characteristic microscopic finding for Blastomyces?

Broad-based budding, appearing as an '8' shape.

How are mild cases of Blastomycosis treated?

Fluconazole or Itraconazole.

How are disseminated cases of Blastomycosis treated?

Amphotericin B followed by Itraconazole.

What are other names for Histoplasmosis?

Ohio disease, darling disease, or cave's disease.

What is the natural reservoir for Histoplasma?

Bat/bird droppings.

Histoplasma yeast forms go into which cells in the body?

Macrophages.

What is the characteristic microscopic structure of Histoplasma seen with a Lactophenol cotton blue stain?

Tuberculate macroconidia.

What is another name for Paracoccidioidomycosis?

South American blastomycosis.

What is the characteristic microscopic appearance of Paracoccidioidomycosis?

Pilot wheel, Mariner wheel, or Mickey Mouse appearance.

What is the current name for Penicillium Marneffei?

Talaromyces marneffei.

What is the natural reservoir for Penicillium Marneffei?

Bamboo rat.

A key identifying feature of Penicillium Marneffei in culture is the production of a _.

red pigment

The LPCB stain of Penicillium Marneffei shows what characteristic structure?

A brush/broom like structure.

What are other names for Coccidioidomycosis?

Desert rheumatism, valley fever, or California disease.

Coccidioidomycosis is associated with joint involvement, leading to a condition sometimes called _.

desert rheumatism

What is the characteristic microscopic structure found in tissues infected with Coccidioidomycosis?

Spherule with endospores.

The spores of Coccidioidomycosis seen in LPCB stain are described as _ shaped arthrospores.

barrel

What is the common name for sporotrichosis?

Rose gardener's disease.

Which organism is responsible for causing sporotrichosis?

Sporothrix schenckii.

How is sporotrichosis typically transmitted?

Through traumatic penetration, such as a rose thorn prick.

What is the characteristic pattern of lesion spread in sporotrichosis?

Nodules spread along the lymphatics.

In sporotrichosis, a round eosinophilic body with surrounding projections is known as a(n) _.

Asteroid body (Splendore-Hoeppli reaction).

What is the term for the yeast form of Sporothrix seen in tissues?

Cigar body.

What is the characteristic arrangement of conidia seen in the mold form of Sporothrix?

Rosettes of conidia.