Flashcards in 12.7: Mycology II Deck (37)
Structure of cryptococcosis?
- ROUND yeast with polysaccharide capsule
- Associated with pigeon droppings and soil
What to think of when you hear pigeon droppings?
What is only yeast with polysaccharide capsule?
2 Varieties of cryptococcosis and where are they endemic?
1. Neoformans: pigeon guano, global
2. Gatii: SW, PNW, mexico
Who is most at risk for cryptococcosis?
Aids patients make up 50% of victims
Pathogenesis of cryptococcosis?
- Inhale into lungs
- Pulmonary infection is usually asymptomatic a
- Likes to spread from lungs to CNS through blood causing disease w/o showing pulm symptoms
- Causes meningitis in CNS
What is required for clearing cryptococcosis?
- T cells
- Recovery associated with humoral immunity
Clinical presentation of cryptococcosis?
1. Meningitis: cranial nerve abnormalities
4. Gait abnormalities
7. Raised skin lesions
***Lead to coma and death if not treated
How to test for cryptococcosis?
- Cryptococcal antigen latex agglutination
- Rapid test of CSF or blood
- Indian ink preparation also works
What does silver stain work well on?
Fungus, yeast, mold
What are dimorphic fungi?
- Grow as yeast at 35 degrees: in our bodies
- Grow as mold at 25 degrees
Which are the dimorphic fungi?
1. Histoplasma capsulatum
2. Blastomyces dermatitidis
3. Coccidioides immitis
4. Sporothrix schenckii "Sporotrichosis"
Reservoir of Histoplasma?
- Bat caves and chicken coops
Endemic area of Histoplasma?
Ohio and Mississippi river valley
Symptoms of Histoplasma?
- Pulmonary infiltrate and lymphadenopathy that can progress to cavitating lesion
- TB like symptoms
- Febrile illness
Hallmark of Histoplasma Capsulatum?
- Organism can grow inside macrophages then spread to liver spleen and marrow
How is Histoplasmosis tested for?
Positive urine antigen test
Which fungi grows and multiples in macrophages?
What is Chicago disease?
Where is Blastomycosis endemic?
- Central US, primarily Chicago: cities that are on waterways
- Increase during rain and when rivers overflow: late fall after a wet summer
Clinical manifestation of Blastomycosis?
2. Chest pain
3. Cough w/ sputum
4. Lytic bone lesions
5. DIsseminated disease
6. Skin lesions
What are "Broad based budding yeast"?
Appearance of Blastomycosis?
Broad based budding yeast on KOH
Other names for Coccidioidomycosis?
"San Joaquin Valley Fever" "Desert Rheumatism"
Other names for "San Joaquin Valley Fever" "Desert Rheumatism"?
Characteristics of Coccidioidomycosis?
- Restricted to desert SWUS
- Not transmitted person to person: inhale spores from dust
Pathogenesis of Coccidioidomycosis?
- Inhaled arthroconidia bypassing upper airway
- Convert to spherule full of endospores in lungs
- Spherules bust and endospores spread
Presentation of Coccidioidomycosis?
1. Erythema Nodosum: rash commonly seen in white women
Lab test for Coccidioidomycosis?
- Blood or skin test, no urine test
What are spherules filled with endospores indicative of?
What is alternating barrel shaped arthroconidia indicative of?
What is Subcutaneous mycoses?
Fungal infection of skin and underlying tissue by fungi without systemic spread
Two types of Subcutaneous mycoses?
What is associated with pricking self on rose thorn in garden?
Presentation of Sporotrichosis?
- Papular skin lesions that enlarge and ulcerate
- Firm nodules along lymphatics
What is cigar or daisy like shape indicative of?