Systemic Mycoses Flashcards Preview

Week 5 of Micro TA presentation > Systemic Mycoses > Flashcards

Flashcards in Systemic Mycoses Deck (31)
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1
Q

List of systemic mycoses

A

Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi

2
Q

Morphology of systemic mycoses

A

Histoplasma, Blastomyces, Paracoccidiodes, Penicillum marneffi are dimorphic: “mold in the cold, yeast in the heat”
1 exception is Coccidioides: “mold in the cold, spherule in heat”
Yeast forms have unique morphologies!

3
Q

Transmission of systemic mycoses

A

For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Respiratory
No person-person

4
Q

Clinical presentation of systemic mycoses

A

For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi

  • Mostly asymptomatic unless immunocompromised. Need high infectivity dose to cause disease in immunocompetent person.
  • All can cause Pneumonia and disseminate (Extrapulmonary Manifestation)
  • can have latent period and reactivation disease.
5
Q

Treatment of systemic mycoses

A

For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Azole for local infection
Amphotericin B for systemic infection

6
Q

Histoplasma Capsulatum epidemiology

A
Inhaled microconidia (spores) from: spelunking, construction work, bat guano (high concentrations), 
Ohio and Mississippi River Valleys and other countries (Caribbean)
7
Q

Histoplasma Capsulatum morphology

A

Dimorphic (mold/yeast), Intracellular (monocytes/macrophages ). In culture see it growing inside of macrophages. Smaller then RBC.

8
Q

Histoplasma Capsulatum Clinical presentation

A

Dissemination/sepsis /reactivation in immunocompromised/defects in CMI with high mortality (>80%);
PULMONARY (can look like miliary TB, or regular TB with granulomas), cardiac, rheumatic conditions; can be asymptomatic

9
Q

Histoplasma Capsulatum diagnosis

A

Most Important: Urine antigen test.
The possible other options: Visualization on sputum with silver stain, peripheral blood smear, bone marrow biopsy, Broncheoalveolar lavage; skin/liver/LN bx poor yield

10
Q

Treatment of histoplasma capsulatum

A

Amphotericin B, Itraconazole, Voriconazole

11
Q

Blastomyces Dermatitidis morphology

A

Dimorphic, saprophytic mold in soil (25C); Broad Based Budding yeast
“Blasto = Broad-Based Buds”
Same size as RBC.

12
Q

Clinical presentation Blastomyces Dermatitidis

A

Pulmonary (chronic pneumonia); cutaneous lesions (papules, nodules, microabscesses – looks like mold) and bone lesions from hematogenous spread
ExtraPulm - “BLaST = Bones, Lungs, and Skin, (TB presentation)”

13
Q

Diagnosis of Blastomyces Dermatitidis

A

Broad-based budding of yeast; silver stain

14
Q

Epidemiology of Blastomyces Dermatitidis

A

Inhalation of spores (rarely cutaneous), environmental (soil, decaying wood, river banks);
geographic overlap with Histo: Great lakes and Ohio River valleys

15
Q

Treatment of Blastomyces Dermatitidis

A

Amphotericin B, itraconazole, fluconazole

16
Q

Coccidioides Immitis morphology

A

Dimorphic: multinucleate spherule and
mold (barrel-shaped arthroconidia is infectious unit).
Spherule filled with endospores in body, not yeast. Larger then RBC.

17
Q

Coccidioides Immitis clinical presentation

A

Asymptomatic (many), flu-like symptoms (10-16 days post-exposure);
San Joaquin Valley Fever in 5% (rash, erythema nodosum (desert bumps), erythema multiforme, joint pain, conjunctivitis);
may disseminate MENINGITIS

18
Q

Diagnosis of Coccidioides Immitis

A

LARGE spherule in culture, PPD-like skin test (type IV hypersensitivity)

19
Q

Epidemiology of coccidioides Immitis

A

Soil in SW US, Latin America; disturbed soil (inhaled spores, which becomes LARGE spherule) –>Military, Archaeologists, Construction workers. Increased rate after earthquakes
“Cocc your gun in the South and knock over a Barrel of spores”
genetic high risk groups: Filipino>African-American>Native Americans

20
Q

Treatment of coccidioides immitis

A

Amphotericin B (+ fluconazole if immunocompromised)

21
Q

paracoccidioides brasiliensis morphology

A

Dimorphic, Mariner’s Wheel (multiples buds w/ narrow stalks)

“Paracoccidio parasails with the Captain’s Wheel all the way to Latin America”

22
Q

Paracoccidioides brasiliensis clinical presentation

A

Lungs –> dissemination; LONG latency (can be > 10 yrs); PULMONARY (necrotizing granulomas, dry cough), lymphadenopathy, sometimes cutaneous fistulae; CXR shows patchy nodular densities and sometimes consolidations; can be asymptomatic

23
Q

Paracoccidioides brasiliensis diagnosis

A

Culture of biopsy or bronchoalveolar lavage  budding yeast with Mariner’s (captain’s) wheel appearance

24
Q

Paracoccidioides brasiliensis epidemiology

A
Latin America (Mexico to Argentina; highest in Brazil); 15:1 male predominance (estrogen may be protective); inhaled spores
“Paracoccidio parasails with the Captain’s Wheel all the way to Latin America”
25
Q

Paracoccidioides brasiliensis treatment

A

Itraconazole OR TMP-SMX, Amphotericin B if severe

26
Q

Penicillum Marneffi morphology

A

Dimorphic Yeast and mold

27
Q

Clinical presentation of penicillum marneffi

A

Pulmonary, dissemination, fever, weight loss, pancytopenia, HEPATOMEGALY, umbilicated skin lesions (cutaneous disseminated disease)

28
Q

Diagnosis of penicillum Marneffi

A

Binary Fission in yeast phase

29
Q

Epidemiology of penicillum marneffi

A

Endemic to tropical Asia; bamboo rat (zoonotic reservoir); immunocompromised
*3rd most common opportunistic infections in endemic area (after TB and Crypto) in AIDS patients in N. Thailand

30
Q

What can cause disseminated skin lesions?

A

Causes umbilicated skin lesions

disseminated cryptococcosis or disseminated histoplasmosis or disseminated penicillumosis

31
Q

Treatment of penicillum marneffi

A

Amphotericin B and 5-Fluorocytosine