Micro 03 - Systemic Mycoses
Terms
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- Five systemic fungi
-
Histoplasma Capsulatum
Blastomyces dermatidis
Paracoccidioides brasilensis
Coccidioides immitis
Cryptococcus neoformans - Systemic fungi infection begins in the ______ and disseminates from there
- Lungs
- Systemic fungi infections usually present initially as ________
- pneumonia
-
4 thermally dimorphic fungi
Systemic fungis that is yeast-like -
1. H. capsulatum
2. P. brasilensis
3. B. dermatidis
4. Coccidioides immitis
Yeast-like = Cryptococcus neoformans -
Dimorphism:
-growth at 25'C in culture is _______
-growth at 37'C is ________ -
Filamentous
Yeast-like or unicellular - Histoplasmosis initial disease characteristics
-
-Flu-like pneumonia
-50-90% have sub-clinical course
-5% show acute pneumonia - Progression of Histoplasmosis disseminated disease is associated with ________
- underlying immunosuppression
-
Histoplasmosis infection route is often associated with ______.
Infection by inhalation of ______
Spores are phagocytosed by _______
-bind to ______ -
bat or bird poop
Conidia (asexual spores)
Macrophage
-CD11/CD18 integrins -
Histoplasmosis:
-__1__ reproduces within macrophage
-interacts with macrophage to suppress generation of __2__
-activively changes pH of __3__
-phagocytosis by __4__ may predispose fungi to be pathogenic on evolutionary scale -
1. Yeast
2. oxygen radicals
3. phagosome
4. Amoeba -
Histoplasmosis:
-__1__ may form in Spleen or Liver - Calcified granulomas
- Distribution of Histoplasmosis
-
Midwest USA
-Ohio and Mississippi River Valleys - Histoplasma that is also present in Africa
-
H. duboisii
-similar to Blastomycosis
-skin, liver, lung, bone -
Histoplasmosis:
-in a healthy individual, following heavy inoculum, __1__ symptoms developing following a LATENCY PERIOD of __2__.
-Host immune system begins inhibiting grown of organism in infected M0 by __3__
-CMI DTH develops within __4 -
1. Flu-like
2. 10-25 days
3. 7-18 days
4. 3-6 wks
5. host survival
6. clearance of organism - Histoplasmosis Pulmonary symptoms
-
Non-productive cough
Fever
Enlarged Lymph nodes - Histoplasmosis Disseminated symptoms
-
Fatigue
Weakness
Malaise - Describe the Thermo-conversion of Histoplasmosis
-
-25'C = rough walled macroconidia on Saouraurd Glucose agar
-37'C = yeast-like colony - Diasnosis of Disseminated Histoplasmosis requires demonstration of organism at ___________
-
Extrapulmonary sites
-immunologic tests are better for monitoring treatment than for primary diagnosis -
Histoplasma Antigen Test:
-__1__ antigen
-titers show how __2__ or __3__ the infection is -
1. Wheat antigen
2. active
3. widespread -
Histoplasmosis Treatment:
-most infections are __1__
-treat acute pulmonary disease if symptoms present greater than __2__ with __3__ followed by __4__ -
1. self-limiting
2. 1 month
3. Amphotericin B
4. Itraconazole - Disease caused by Blastomycosis
- Pneumonia/skin and/or bone lesions
- Blastomycosis is asymptomatic in up to ____% of cases due to some natural resistance
- 50%
- Describe the pneumonia associated with Blastomyces
- indolent onset of pneumonia with a 30-45 day incubation!!!
- Blastomycosis causes Extrapulmonary disease in what percent of patients?
- 25-40%
- Geographic distribution of Blastomycosis
-
NOrth America and parts of Africa
Endemic in UPPER and CENTRAL MIDWEST - Blastomycosis exists in these animals (2)
-
dogs
Horses - Point source outbreaks of Blastomycosis are associated with _________
- rotting vegetation along streams or rivers
- Part of the body that is commonly infected with Blastomyces in HIV patients
- CNS
-
Blastomycosis:
-sexual infection in genus __1__
-infection by inhalation of __2__
-spores are phagocytosed by __3__
-yeast reproduces within _4_
-__5__adhesion inhibits TNF-alpha.
-__6__ are not present -
1. Aiellomyces
2. conidia
3. macrophages
4. macrophages
5. W1-1
6. Calcifications - Diagnosis of Blastomycosis
-
-Culture from tissue
-Broad-based budding yeast cells
-MiraVista Ag detection - List the differences between Histo and Blasto
-
* - DOC for mild Blastomycosis
- Itraconazole for 2 months
- Life threatening treatment for Blastomycosis
- AmB then Itraconazole
- Treatment for Disseminated Blasto
- Amphtotericin B or Fluconazole followed by Itraconazole
- Cure rate of Blastomycosis with this drug is very high
-
Amphotericin B
-relapse rate ~3% - nickname for Paracoccidiomycosis
- South American Blastomycosis
- Paracoccidiomycosis infections occur where geographically?
- South and Central America
- Most infections of Paracoccidiomycosis occur in this group of people
-
Men aged 20-50
-especially coffee growers
*9X more common in men - Paracoccidiomycosis lesions are where?
-
Oral and Nasal Cavity - Describe the Pulmonary infection of Paracoccidiomycosis
-
Asymptomatic or
Cough, purulent sputum, chest pain
Lymphadenopathy -
Paracoccidioides brasiliensis exists in __1__
Infection follows inhalation of __2__.
Spores convert to yeast at _3_
Mycelia to yeast transition is inhibited by __4__
Lesions are secondary to __5__ -
1. soil
2. conidia
3. 37'C
4. 17-B-Estradiol
*why women not infected*
5. pulmonary infection - Diagnosis of Paracoccidiomycosis
-
Ships-wheel arrangement of spores
-2 to 20 microns in diameter
-doubly refractile wall - Paracoccidiomycosis treatment
-
-Sulfa drugs are used in S. America but require long-term administration
-Itraconazole and Voriconazole are best treatment (6 months)
**relapse if frequent** - 2 causative agents of Coccidioidomycosis
-
Coccidioides Immitis
C. posadsii - Coccidioidomycosis is often called ______
- Valley Fever
- Most common disease of Coccidioidomycosis
-
Pneumonia
*night-sweats and joint pain*
*5-10% have nodules/cavities* - Where is Coccidioidomycosis endemic?
-
SW USA
also in Argentina and Paraguay - In what things is Coccidioidomycosis found?
-
Soil, Dust as Arthrospores (spore that results from fragmentation of hyphae)
Chimpanzee, Horses - Patients of these descents are at a higher risk of dissemination with Coccidioidomycosis
-
African
Philippino -
Coccidioidomycosis:
-once inhaled, C. immitis dust-borne artho-conidia convert at 37'C to form large __1__ in tissue -
spherules -
Coccidioidomycosis:
-Spherules burst releasing __1__ which grow to form new __2__ -
1. Endospores
2. spherules - Diagnosis of Coccidioidomycosis
-
-Spherules in stained tissue
-Complement fixation for IgG anticoccidioidal Ab's
-Culture
-Antigen preps - When is treatment for Coccidioidomycosis pneumonia recommended?
-
-if patient loses >10% of body weight
-if night-sweats persist >3 wks. - Coccidioidomycosis treatment for non-meningeal spread
- Itraconazole
- Coccidioidomycosis treatment for meningitis
-
Fluconazole
Intrathecal AmB
*follow-up for 2 years -
Coccidioidomycosis:
-mortality up to __% in AIDS in 1 month
-__ is more relevant than HIV status -
70
CD4 count -
Cryptococcosis commonly causes relapsing _______
It is sometimes considered ______ -
meningitis
Opportunistic - Difference between Cryptococcosis and other systemic mycoses
- Not Thermally Dimorphic
- Cryptococcosis is related to _______
- common jelly fungus
- Alternate names for Cryptococcosis
- Torulosis or European Blastomycosis
- Unique feature of Cryptococcus neoformans
- acidic mucopolysaccharide capsule
- Cryptococcus is associated with these two things
-
Pigeon poop
Eucalyptus trees -
Cryptococcosis:
-infection is initiated by inhalation of organism from the __1__
-spread from lungs occurs via the __2__
-is a defining illness for __3__
-first identified as causing __4__ in 1905
-disseminates to __5__ -
1. soil
2. blood
3. AIDS
4. meningitis
5. prostate (skene's gland in females) - Cryptococcosis clinically most often presents as ______
-
Meningitis
-headache
-fever of several weeks
-sometimes solitary pulmonary nodule - Diagnosis of Cryptococcosis
-
-India ink prep shows acidic capsule = use for IC'ed
-Antigen test for detection of polysaccharide in CSF - Treatment for Cryptococcosis
- AmB + FLUCYTOSINE then Fluconazole