FA - Micro - Mycology Flashcards
Treatment for systemic mycosis?
- Fluconazole (local infection)
- Itraconazole (local infection)
- Amphotericin B (systemic infection)
3 features about systemic mycoses?
- ALL can cause pneumonia
- Can disseminate
- ALL caused by dimorphic fungi: cold (20C)=mold, heat(37C)=yeast.
Only exception: Coccidioidomycosis - spherule (not yeast) in tissue.
Systemic mycosis can mimic what?
TB (granuloma formation), EXCEPT, unlike TB, have no person-person transmission.
Histoplasmosis - Endemic location?
Mississippi and Ohio river valleys.
Histoplasmosis cause?
Pneumonia.
Histoplasmosis special feature?
Macrophage filled with Histoplasma (smaller than RBC) - Histo Hides (within macros).
BIRDS (eg starlings) and BATS droppings.
Blastomycosis - Endemic location?
States east of Mississippi River and Central America.
Blastomycosis - cause?
Inflammatory lung disease - can disseminate to skin and bone.
Forms granulomatous nodules.
Blastomycosis - Special feature?
Broad-base budding (same as RBC).
Coccidioidomycosis - Endemic location?
Southwestern US, California.
Coccidioidomycosis - cause?
- Pneumonia
- Meningitis
- Can disseminate to bone and skin.
Coccidioidomycosis - Special features?
- Case rate UP after earthquakes (spores in dust are thrown up in the air and become spherules in the lungs).
- Spherule (MUCH LARGER than a RBC) filled with endospores.
Paracoccidioidomycosis - Endemic location?
Latin America.
Paracoccidioidomycosis - Special feature?
Budding yeast with “captain’s wheel” formation (MUCH LARGER THAN RBC).
Tinea versicolor - Cause?
Malassezia spp. (Pityrosporum spp.) ==> A yeast-like fungus (NOT A DERMATOPHYTE despite being called tinea).
Tinea versicolor - Pathogenesis?
Degradation of lipids produces acids that damage MELANOCYTES –> hypopigmented and/or PINK patches.
Tinea versicolor - When?
Can occur ANY TIME of year, but more common IN SUMMER ==> Hot, humid weather.
Tinea versicolor - treatment?
- Topical miconazole
2. Selenium sulfide (Selsun)
Tinea versicolor - Microscopic morphology?
“Spaghetti and meatball” appearance.
Other tineae?
Tinea pedis Tinea cruris (groin) Tinea corporis Tinea capitis Tinea unguium (onychomycosis, on fingernails)
Other tineae - Features?
Pruritic lesions with central clearing resembling a RING.
Other tineae - causes?
By dermatophytes - Microsporum, Trichophyton, Epidermophyton.
Dermatophytes - Microscopic morphology?
BRANCHING SEPTATE HYPHAE visible on KOH preparation with BLUE FUNGAL STAIN.
C.albicans - causes?
- Oral-esophageal thrush in immunocompromised (Neonates+ Steroids + Diabetics + AIDS).
- Vulvovaginitis (diabetes, use of antibiotics).
- Diaper rash
- Endocarditis in IVDA
- Disseminated candidiasis (any organ)
- Chronic mucocutaneous candidiasis