Flashcards in Fungi Deck (41)
What is the main difference between fungal and bacterial cell walls?
Fungal cell wall--made of chitin
Bacterial cell wall--made of peptidoglycan
What are dimorphic fungi?
Fungi that are yeasts at 37C and molds at lower temperatures.
Circular, scaling lesion with central clearing and hair loss
Malassezia furfur appearance
Spaghetti (short septae hyphae) and meatballs (small yeasts)
Cauliflower-like verrucous (warty) nodules
Dematiaceous (brown or black, melanin-producing) sclerotic bodies
White, curd-like, adhesive plaques that bleed when removed for culture
Prolonged use of antibiotics
Septate branching hyphae
Black nasal discharge
Coenocyte (aseptate) hyphae
Paranasal sinus and ocular orbit involvement
Rhizopus and Mucor species
What are the main differences between systemic and opportunistic infection agents?
Disease often is asymptomatic or resolves quickly in both normal and compromised hosts
Endemic in limited geographic area
Usually not part of normal flora
Dimorphic (except Cryptococcus)
Disease often is serious primarily in compromised hosts
Usually part of normal flora
Not dimorphic (except Candida)
Cup shaped ("flying saucer")
Diffuse interstitial pneumonia
Fluffy, foamy alveolar exudate
Gomori silver stain
Ground-glass appearance on radiograph
IV drug abuser
Organisms in lavage lung
Midwestern U.S. (Mississippi River Valley)
Eastern U.S. ; Central America
Broad-based budding yeast
Healthy and immunocompromised
American southwest deserts
San Joaquin River Valley
Skin test for antigen exposure
India ink preparations
YEASTS INSIDE MACROPHAGES
Bird and BAT droppings
Lung and spleen
Ohio and Mississippi River Valleys
35 y/o man has a URI. His sputum is blood stained. A chest radiograph shows a ball-like mass of fungal hyphae in an apical cavity.
"Ball-like mass of fungal hyphae" = aspergilloma
An otherwise healthy man who had successfully recovered from a URI marked by fever, cough, and chest pain 3 months ago now develops several chronic suppurative skin lesions. A chest radiograph shows pulmonary infiltrates.
An HIV-positive man has white patches on the tongue.
A 39 y/o woman who has diabetes is being treated with abx for a bacterial infection. She develops vaginal pruritus, erythema, and a thick, creamy vaginal discharge.
After vacationing in the desert areas of New Mexico, a 40 y/o woman develops a URI with pulmonary infiltrates and has red, nodular, painful lesions on both shins.
An immunosuppressed woman has a chronic headache and stiff neck. India ink preparation of CSF shows encapsulated yeast cells.
A chicken farmer living in southern Ohio has a mild respiratory infection with flu-like symptoms that resolve within 10 days. Two months later, numerous diffuse, small calcific densities are seen on chest radiograph.
A diabetic patient in ketoacidosis has a frontal lobe abscess.
An AIDS patient with a low CD4 cell count has a respiratory infection with fever, cough, SOB, and pulmonary infiltrates.
A woman develops suppurating, nodular skin lesions on the lower arm after pruning rose bushes in her garden.
What is the most virulent agent of systemic fungal infection?
Rural Latin America
Budding yeast cells ("steering wheels")
Which fungi are dimorphic?
Which fungi are opportunistic?
Mucor and Rhizopus species