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fungal Pneumonia's 10/2/06


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1. what are Endemic dimorphic fungi in US?

2. Opportunistic fungi
1. Blastomyces dermatitidis
Coccidioides immitis
Histoplasma capsulatum

2. Candida sp
Aspergillus sp
Mucor sp.
Pneumoncystis jiroveci
2. What is endemic?

2b. what is dimorphic? what are they?
2. geographic

2b. Exist in 2 morphologically different forms
1. Molds- multicellular, thread-like hyphae found in environment (free-living phase)
2. Yeasts- single cell form found in tissues (parasitic phase)
3. what do you inhale in endemic fingal LRTI?

3b. What holds it in chesk

3c. when is it reactivated?
Can result following inhalation of conidia

May be self-limiting disease held in check by CMI. Organisms persist but fail to grow as long as anti-fungal CMI is strong

Can be reactivated if individual become immune suppressed
4. Histoplasma capsulatum - where is it found?

4b. what enhances its growth?

4c. 3 specific envirmonments?
Soil organism

4b.Growth in soil enhanced by bird or bat guano (poop)

4c.Specific types of environments
Chicken coops
Old buildings
5. What is conidia transformed into with the body's high temp?

5b. What attacks them?

5c. What is killing them dependent on?
Transform into yeasts

Phagocytosed by macrophages but are not killed

Killing of intracellular yeast depends on Th1 cell activation of macrophages through release of g-IFN

FYI - By this time, organisms have spread widely in lung
histoplasma capsulatum continued...
6. What does it appear as in the lungs?

6b. What happens in the long run to them on CXR?
6a. Granulomas form around infected macrophages

6b. Later they calcify (can see this on CXR)
Organisms remain viable in granulomas for years
Clinical manifestations of histoplasma capsulatum:
7. what is initial illness like?

7b. what is the DX and treatment?
7a. Flu like symptoms

7b. culture of sputum (KOH) and bx lung tissue shows yeast in the macs
Severe - amphotericin B, and mild to moderate - itraconazole
Blastomyces dermatitidis
8. where is this found in nature?

8b. Where is this found in the US?
8a. soil organism found in decaying LEAF matter

8b. Central and eastern US
9. Blastomycosis is similar pathogenesis to Histoplasma.

But what is the key finding that seperates Blasto from histo?
Blasto has skin lesions!!!

FYI - same treatment
10. Coccidioides immitis (is the fungal form) of Coccidioidomycosis

a. Where is it found?

b. Pathogenesis
a. Semi arid regions of the SW USA

b. Probably associated with burrows of desert animals
Grows rapidly following rain; drought and windy conditions spread organism large distances
Many people in area have serologic evidence of prior infection
11. Coccidioidomycosis

a. you inhale the conidia into your alveli --> what happens next

b. Are they a yeast?

c. How do you control the infection?

d. WHAT SEPERATES Cocci form histo and blasto?
a. conodia Transformation into a spherule containing endospores

b. NO!! they are extracellular

c. Control with Th1 cells and macs.

d. there is PAIN (ARTHRALGIA) in addition to fever and dry cough. (same THX)
12. You know that Candida is part of normal flora of nasopharynx, skin, vagina, but which one is responsible for most infections?

(FYI) - start of oppostunistic fungi

b. 4 Causes of infection with candida
C. albicans is responsible for most infections

b. T cell immune suppression
Antibiotic therapy
Insertion of catheter
13. Candida albicans,

a. What Dz are associated with it?

b. Where do you cultue it?
a. Disease associations
Vaginal yeast infections
Hepatospenic candidiasis

b. Culture of blood or biopsied lung tissue
Blood agar or Sabouraud’s agar
14. You find this fungus espically in the renovation of old buildings (damp, musty places)

b. what is the key histological appearance of the hyphae?

c. Treatment?
14a. Aspergillus!

b. Histopathology of infection- see acutely branching septate hyphae; may see fruiting bodies in lung
(FYI - Organism can invade blood vessels to disseminate, leading to necrotic skin lesions and brain abscesses)

c. Amphotericin B, voriconazole, caspofungin
This fungal infection is commonly seen in AIDS, once thought yo be a protozoan, and Replicates in the surfactant layer above the alveolar epithelium
Forms trophozoites and cysts
As proliferation continues, damage to basement membrane occurs alt
Pneumocystis jiroveci!!!
16. What are the clinical manifestations of Pneumocystis jiroveci?

b. DX is made with?

c. Treatment?
a. Clinical Manifestations
Dyspnea, dry cough, fatigue plus or minus low grade fever

b.Microscopic examination of BAL fluid stained with Giemsa, toluidine blue, methenamine silver
See thin walled trophozoites and thick walled cysts containing 4-8 nuclei

c.Treatment and prevention

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