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Flashcards in Micro Mycology Deck (13):
1

Systemic Mycoses
Names
Disease caused by it...
Kind of organisms?
Temperature
Treatment
What might it be confused with?

Histoplasmosis, Blastomycosis, Coccidioidomycosis, Paracoccidioidomycosis
Can cause pneumonia and disseminate
Dimorphic fungi:
Cold (20) = mold. Heat (37) = yeast. Except for Coccidio which is a spherule in tissue (not yeast)
Fluconazole or Itraconazole for local infections. Amphotericin B for systemic infections
Can mimic TB (form granulomas) except no person-to-person transmission

2

Histoplasmosis
Presentation
Location
Vectors
Histo

Pneumonia
Mississippi and Ohio River Valley
Bird or bat droppings
Macrophage filled with Histoplasma (smaller than RBCs)
"Histo Hides in macs"

3

Blastomycosis
Presentation
Histo
Location

Inflammatory lung disease and can disseminate to skin and bone
Forms granulomatous nodules. Broad-base budding (same size as RBCs)
States east of Mississippi river and in Central America

4

Coccidioidomycosis
Presentation
When do rates go up?
Histo
Location

Pneumonia and meningitis. Can disseminate to bone and skin
Cases ↑ after earthquakes
Spherule filled with endospores (much larger than RBCs). At higher temps: Hyphae
Southwestern US and California
San Joaquin Valley or desert (desert bumps) - Valley Fever

5

Paracoccidioidomycosis
Location
Histo

Latin America
Budding yeast with Captain's Wheel formation (much larger than RBCs)
"Paracoccidioidomycosis parasails with the captain's wheel all the way to Latin America"

6

Tinea versicolor
What is it caused by?
Weapons
Presentation
Histo
Location where it occurs
Treatment

Malassezia furfur - yeast fungi
Degrades lipids and that produces acids that damage melanocytes
Hypo- or hyperpigmented patches
Spaghetti and meatball appearance on KOH prep
Hot, humid weather
Topical mconazole, Selenium sulfide (Selsun)

7

Other Tinea
Organisms that cause it
What does it cause?
Names with location of infection
Presentation
Histo
Life cycle

Dermatophytes (Microsporum, Trichophyton, Epidermophyton)
Ringworm
Tinea pedis (foot), Tinea cruris (groin), Tinea corporis (ringworm on body), Tinea capitis (head, scalp), Tinea unguium (onychomycosis on fingernails)
Pruritic lesion with central clearing (ring)
Mold hyphae on KOH prep. Not dimorphic

8

Candida albicans
What is it?
Who is susceptible?
What does it cause?
Treatment
Histo

Opportunistic fungal infection
Immunocompromised
Oral and esophageal thrush in Immunocompromised (neonates, steroids, diabetes, AIDS), Vulvovaginitis (diabetics, antibiotic use), Diaper rash, Endocarditis in IV drug users, Disseminated Candidiasis (to any organ), Chronic Mucocutaneous Candidiasis
Topical azole for vaginal. Fluconazole or caspofungin for oral/esophageal. Fluconazole, amphotericin B or Caspofungin for systemic
Forms germ tubes at 37

9

Aspergilus fumigatus
What is it?
Who is susceptible?
What diseases does it cause?
Weapons
Life cycle
Histo

Opportunistic fungal infection of immunocompromised and those with chronic granulomatous disease
Allergic bronchopulmonary aspergillosis (w/ asthma or CF), Aspergillomas in lung cavities (after TB infection)
Aflatxins associated with HCC
Not dimorphic
Septate hyphae that branch at 45 deg angles. Conidiophore with radiating chains of spores
"A for Acute Angles in Aspergillus"

10

Cryptococcus neoformans
What is it?
Diseases caused by it?
Histo
Life cycle? Where is it found?
Transmission? Growth? Stains?
Test? Kind of lesion?

Opportunistic fungal infection
Cryptococcal meningitis, Crytpcoccosis
Heavily encapsulated yeast (wide capsular halos). Unequal budding
Not dimorphic. Found in soil, pigeon droppings. Acquired through inhalation to the lungs with hematogenous dissemination to meninges
Culture on Sabouraud's agar. Stains with India ink
Latex agglutination test detects polysaccharide capsular Ag
Soap bubble brain lesion

11

Mucor and Rhizopus Species
What is it?
What do they cause?
Who gets it?
PathoPhys
What doe they form?
Presentation
Histo

Opportunistic fungal infection
Mucormycosis
DKA and leukemic pts
Proliferate in blood vessel walls when there is excess ketone and glucose
Penetrate cribriform plate and enter brain forming Rhinocerebral, Frontal lobe abscesses
Headache, Facial pain, Black necrotic eschar on face. May have CN involvement
Irregular broad nonseptate hyphae branching at wide angles

12

Pneumocystis jirovecii
What is it?
Who is at risk?
What does it cause?
Transmission
Presentation. XR. Diagnosis
Histo
Treatment

Opportunistic fungal infection (yeast)
Immunosuppressed (AIDS)
Pneumocystis pneumonia (PCP) - a diffuse interstitial pneumonia
Inhaled
Asymptomatic. Diffuse bilateral CXR appearance
Lung biopsy or lavage. Disc-shaped yeast forms on methenamine silver stain of lung tissue
TMP-SMX, Pentamidine, Dapsone. Start prophylaxis when CD4 drops below 200 in HIV pts

13

Sporothrix schenckii
What is it?
What does it cause?
Life cycle
Histo
Where do they live? Transmission?
Presentation
Treatment

Opportunistic fungal infection
Sporotrichosis
Dimorphic. Cigar shaped budding yeast
Lives on vegetation
Spores traumatically introduced into skin by thorns
Local pustule or ulcer with nodules along draining lymphatics (ascending lymphangitis) without systemic illness
Itraconazole or Potassium iodide
"Plant a rose in the pot" "Rose gardeners disease"