Microbio-Mycology

Question 0

Causes pneumonia and can disseminate. @20C=mold, @37C=yeast
Mississippi and Ohio River valleys. Found in bird and bat droppings. Can form palatal/tongue ulcers, splenomegaly. This organism hides within the macrophage.

Answer 0

Histoplasma- causes histoplasmosis

Question 1

Causes pneumonia and can disseminate. @20C=mold, @37C=yeast
States east of Mississippi River and Central America. Causes inflammatory lung disease and can disseminate to skin and bone. Forms granulomatous nodules. Verrucous lesions can mimic SCC. Broad-base budding (same size as RBC).

Answer 1

Blastomycosis

Question 2

Causes pneumonia and can disseminate. @20C=mold, @37C=spherule in tissue. Found in southwestern US and California. Rates increase after earthquakes. Causes pneumonia and meningitis; can disseminate to bone and skin. Erythema nodosum (desert bumps), Arthralgias (desert rheumatism). Spherule (much larger than RBC) filled with endospore.

Answer 2

Coccidioidomycosis

Question 3

Causes pneumonia and can disseminate. @20C=mold, @37C=yeast
Found in Latin America- budding yeast with “captain’s wheel” formation (much larger than RBC). Similar clinic presentation to blastomycosis but males>females

Answer 3

Paracoccidioidomycosis

Question 4

Cutaneous mycoses- caused by Malassezia furfur. Degradation of lipids produces acids that damage melanocytes and cause hypo pigmented and or hyper pigmented patches. Occurs in hot, humid weather. –>Spaghetti and meatball appearance. What is the diagnosis?

Answer 4

Tinea versicolor

Question 5

Includes tinea pedis, tinea cruris (groin), tinea corporis (ringworm, on body), tinea capitis (head scalp), tinea unguium (onychomycosis, on fingernails). Pruritic lesions with central clearing resembling a ring, caused by dermatophytes.

Answer 5

Other Tineae

Question 6

Opportunistic fungal infection- systemic or superficial fungal infection. Oral and esophageal thrush in imunocompromised (neonates, diabetics, steroids, AIDS). Vulvovaginitis, diaper rash, or disseminated infection to any organ/chronic mucocutaneous membrane spread.

Answer 6

Candida albicans

Question 7

Opportunistic fungal infection- invasive in immunocompromised and those with chronic granulomatous disease. Assoc. w/asthma and CF; may cause bronchiectasis and eosinophilia. Found in cavities after TB infection. Some produce aflatoxins, which are assoc. w/hepatocellular carcinoma. Not dimorphic. Grow at acute 45* angles.

Answer 7

Aspergillus fumigatus

Question 8

Opportunistic fungal infection- heavily encapsulated yeast; not dimorphic. Found in soil, pigeon droppings. Acquired through inhalation with hematogenous dissemination to meningitis. Culture on Sabouraud agar. “Soap bubble” lesions in brain.

Answer 8

Cryptococcus neoformans - can lead to cryptococcal meningitis, or cryptococcosis.

Question 9

Opportunistic fungal infection- disease usually found in ketoacidic diabetic and leukemia patients. Fungi proliferate in blood vessel walls when there is excess ketone and glucose, enter cribiform plate and enter brain. Rhinocerebral frontal lobe abscess. Headache, facial pain, black necrotic eschar on face; may have CN involvement.

Answer 9

Mucor and Rhizopus spp. –> Mucormycosis

Question 10

Opportunistic fungal infection- causes a type of pneumonia; a diffuse interstitial pneumonia. Yeast inhaled. Most infections are symptomatic. Immunosuppression predisposes disease. Ground glass appearance on imaging. Disc-shaped yeast forms on methenamine silver stain of lung tissue.

Answer 10

Pneumocystis jirovecii

Tx/profilaxis: TMP-SMX, pentamidine

Question 11

Causative agent for tinea versicolor… not a dermatophyte. Degradation of lipids damages melanocytes causing hypopigmented and or pink patches.

Answer 11

Malassezia spp.

Question 12

Dimorphic cigar-shaped budding yeast that grows in branching hyphae with rosettes of conidia. causes pustule or ulcer along draining lymphatics. What is the microorganism and treatment?

Answer 12

Sporothrix schenckii - Called rose-gardener’s thumb–> TX- intraconazole or potassium-iodide.

Question 13

What mycotoxins infection is at hand??
Narrow budding, heavily encapsulated yeast. Found in soil and pigeon droppings. Acquired through inhalation with hematogenous dissemination to meninges.

Answer 13

Cryptococcus neoformans

Question 14

What mycotoxins infection is at hand??

Irregular, broad, nonseptate hyphae branching at WIDE ANGLES

Answer 14

Mucor and Rhrizopus

Question 15

What mycotoxins infection is at hand??

Septate hyphae that branch at 45 degrees (acute angles)

Answer 15

Aspergillus fumigatus

Question 16

This type of mycoses is known for its broad based budding and is the same size as a RBC. Which one is it, and what clinical findings are characteristic?

Answer 16

Blastomycosis

Inflammatory lung disease, may disseminate to bone or skin (verrucous lesions) that look like SCC.

Question 17

This fungus can be systemic or superficial - forms pseudo hyphae and budding at 20C, or term tubes at 37C. Which microorganism is at hand?

Answer 17

Cándida albicans

Question 18

This mycotic disease is associated with asthma and cystic fibrosis, may cause bronchiectasis and eosinophilia. What is it, and the cause?

Answer 18

Allergic bronchopulmonary aspergillosis- aspergillus fumigatus

Question 19

This microorganism can form palatal/tongue ulcers, splenomegaly. This organism hides within the macrophage.

Answer 19

Histoplasma

Question 20

This microorganism may cause pneumonia and meningitis; can disseminate to bone and skin. Erythema nodosum (—— bumps), Arthralgias (—— rheumatism).

Answer 20

Coccidioidomycosis