Fungi Flashcards
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 Crumbling nails Jock itch Discoloring Keratin Ringworm Azoles
Tinea
Malassezia furfur appearance
Spaghetti (short septae hyphae) and meatballs (small yeasts)
Gardener Nodular lesions Roses Splinter Thorn prick
Sporothrix schenckii
Cauliflower-like verrucous (warty) nodules
Dematiaceous (brown or black, melanin-producing) sclerotic bodies
Skin disease
Chromoblastomycosis
Cobblestones Immunocompromised Thrush Vaginal yeast White, curd-like, adhesive plaques that bleed when removed for culture Prolonged use of antibiotics
Candida albicans
Allergic bronchopulmonary Angioinvasive Fruiting bodies Fungus ball Hypersensitivity pneumonitis Malt/grain workers Septate branching hyphae
Aspergillus species
Acidotic diabetic Black nasal discharge Bread mold Coenocyte (aseptate) hyphae Paranasal sinus and ocular orbit involvement
Rhizopus and Mucor species
What are the main differences between systemic and opportunistic infection agents?
Systemic: 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)
Opportunistic: Disease often is serious primarily in compromised hosts Found worldwide Usually part of normal flora Not dimorphic (except Candida)
AIDS patients
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 lungPneumocystis jiroveci
Midwestern U.S. (Mississippi River Valley) Eastern U.S. ; Central America Rotting wood Beaver dams Broad-based budding yeast Granuloma Healthy and immunocompromised
Blastomyces dermatitidis
American southwest deserts San Joaquin River Valley Skin test for antigen exposure Spherules Desert bumps
Coccidioides immitis
AIDS patients PIGEON DROPPINGS Capsular antigens Capsule India ink preparations Meningitis
Cryptococcus neoformans
YEASTS INSIDE MACROPHAGES Caves Bird and BAT droppings "Cincinnati spleen" Granulomas Lung and spleen Ohio and Mississippi River Valleys
Histoplasma capsulatum
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.
Aspergillus species
“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.
Systemic blastomycosis
Blastomyces dermatitidis
An HIV-positive man has white patches on the tongue.
Oral thrush
Candida albicans
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.
Yeast infection
Candida albicans
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.
Coccidioides immitis
An immunosuppressed woman has a chronic headache and stiff neck. India ink preparation of CSF shows encapsulated yeast cells.
Cryptococcal meningitis
Cryptococcus neoformans
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.
Histoplasma capsulatum
A diabetic patient in ketoacidosis has a frontal lobe abscess.
Mucor species
An AIDS patient with a low CD4 cell count has a respiratory infection with fever, cough, SOB, and pulmonary infiltrates.
Pneumocystitis jiroveci
A woman develops suppurating, nodular skin lesions on the lower arm after pruning rose bushes in her garden.
Sporothrix schenkii
What is the most virulent agent of systemic fungal infection?
Coccidioides immitis
Rural Latin America
Budding yeast cells (“steering wheels”)
Paracoccidioides brasiliensis
Which fungi are dimorphic?
Blastomyces dermatitidis Coccidioides immitis Histoplasma capsulatum Paracoccidioides brasiliensis Sporothrix schenckii Candida albicans
Which fungi are opportunistic?
Aspergillus fumigatus Candida albicans Mucor and Rhizopus species Pneumocystis jiroveci Cryptococus neoformans
Which fungi are systemic?
Coccidioides immitis
Histoplasma capsulatum
Blastomyces dermatitidis
Paracoccidioides brasiliensis
Disease features of Blastomyces dermatitidis
Lung infection with hemoptysis
Invasive form: blood vessels often involved
Allergic form: respiratory distress increasing with age
Which fungi are transmitted via inhalation of spores or yeast?
Aspergillus fumigatus Blastomyces dermatitidis Coccidioides immitis Histoplasma capsulatum Mucor and Rhizopus species Paracoccidioides brasiliensis Cryptococcus neoformans Pneumocystis jiroveci
Candida albicans treatment
Subcutaneous: Azole
Oral thrush: Nystatin
Systemic: Amp-B
Coccidioides treatment
Amp-B
Azole
Cryptococcus neoformans treatment
Amp-B + Flucytosine for meningitis (Fluconazole second line)
Long term Fluconazole in AIDS patients
Histoplasma capsulatum treatment
Amp-B for acute disease
Long term Itraconazole for AIDS patients
Mucor and Rhizopus treatment
Surgery to remove necrotic tissue
Amp-B
Pneumocystic jiroveci treatment
TMP-SMX
Pentamidine
Clinda
Sporothrix schenckii treatment
Potassium iodide (oral)
Amp-B
Itraconazole
Blastomyces dermatitidis treatment
Azoles
Amp-B for serious cases
Aspergillus fumigatus treatment
Surgery to remove infected tissue
Amp-B
Azoles
Echinocandins
