Fungi Flashcards
Identify the major virulence/toxicity factors associated with Penicillium. (1)
fungal spores have mycotoxins
Describe a typical Tinea lesion. (2)
pruritic lesion with central clearing resembling a ring.
What is the presentation of Blastomyces dermatiditis infection? (3)
gilchrist’s disease (blastomycosis)-mild infection in the lungs followed by ucerative granulomas of the skin or bone if infection becomes disseminated.
How are coccidioldomycosis and histoplasmosis transmitted?
inhalation of asexual spores
What is the morphology of C. albicans in culture at 37 degrees C?
germ tubes
What lab findings are useful to help diagnose Histoplasma capsulatum? (2)
chest x-ray shows ‘millet seed’ pattern; Hyphae visible if cultured on Sabouraud’s agar.
What lab findings are useful to help diagnose Pneumoncystis carinii? (2)
organism seen in microscopic examination of lung tissue or lavage; sputum cultures negative
What is the morphology of Aspergillus fumigatus?
mold with septate hyphae that branch at a V-shaped (45 degree) angle
What is the morphology of Rhizopus?
white ‘cotton candy’ colonies that turn brown with age
Is Cryptocuccus neoformans domorphic?
no
How is Coccidiodes immitis transmitted?
inhaled as spores
What predisposes to disease with Pneumocystis carinii?
most infections asymptomatic. Immunosupression (e.g., AIDS) predisposes to disease.
What regions are associaed with Histoplasma capsulatum? (2)
endemic to Ohio and Mississippi river valleys
How is Histoplasmosis capsulatum transmitted?
bird or bat droppings
What are the clinical manifestations of Cladosporium? (2)
allergic reactions to spores. Opportunistic lung infections possible in immunocompromised patients.
What are the clinical manifestations of Alternaria?
allergic reactions and hypersensitivity pneumonitis to spores
What disease does Pneumocystis carinii cause?
causes pneumonia (PCP)
What is ‘most common’ associated with Cladosporium?
maybe the most common source of indoor and outdoor spores.
What is the morphology of C. albicans in culture at 20 deg C?
budding yeast with pseudohyphae
Identify the major at risk population associated with Pneumoncystis carinii.
aIDS and other immunosupressed patients
Identify relevant epidemiology and risk factors associated with Candida albicans. (2)
aIDS, diabetes mellitus
What is the morphology of Stachybotris?
black slimy mold
What is the morphology of Histoplasma capsulatum?
dimorphic fungus (yeast/mold)
What are the clnical manifestations of Cryptococcus neoformans? (2)
only causes diseases in immunocompromised. Meningitis insidious presentation-occasional headache, irritability, difficult cognition, mild fever. Relapse common.
Is Aspergilius fumiatus dimorphic?
no
What are the clinical manifestations of Aspergillus? (5)
ottitis externa; fungal sinusitis; allergic bronchopulmonary aspergillosis; fungus ball; sepsis
What type of budding patter is seen in Cryptococcus neoformans?
narrow-based unequal budding
What are the clinical manifestations of Pullalaria?
allergic reaction to spores
What are the clinical manifestations of Tinea?(3)
ringworm-pruritic papules, broken hair, thick broken nails
Describe the morphology of Blastomyces dermatiditis as revealed by KOH prep.
kOH preparation shows round double refractive wall with single broad-based budding yeast.
What special lab test does the capsule of Cryptocuccus neoformans permit?
latex agglutination test detects polysaccharide capsular antigen
What disease does C. albicans cause in immunocompromised patients?
Oral thrush in throat (neonates, steroids, diabetes, AIDS)
What is the morphology of Cryptococcus neoformans?
heavily encapsulated yeast
What lab findings are useful to help diagnose Cryptococcus neoformans? (6)
urease positive; encapsulated; spinal tap reveals pleocyosis, increased lymphocytes, low glucose, and organism that can be cultured.
Cryptococcus neoformans stains best with which substance?
india ink
What disease does C. albicans cause in babies?
diaper rash
What region is associated with Coccidioides immitis?
endemic in the southwest US
Is C. albicans, infection local, systemic, or both?
both
What class of organism is Pneumocystis carinii?
yeast (originally classified as protozoan)
What are the clinical manifestations of Candida albicans? (3)
thrush-white patches on red base can be scraped off. Candidal vaginitis-erythema, white discharge, itching and burning. Red patches with satellite pustules. Chronic mucocutaneous candidiasis-multiple red, pustular or thick lesions, esp on face.
What are the clinical manifestations of Penicillium?
allergy (spores); penicilliosis (in AIDS)
What do you culture Cryptococcus neoformans on?
culture on Sabouraud’s agar
What lab findings are useful to help diagnose Coccidioides immitis? (3)
tissue and sputum samples show spherules; XCR shows coin-shaped lesions; Serum will show specific antibodies
Why is the disease caused by Coccidioidomycosis called valley fever?
common in the San Joaquin Valley
What are the clinical manifestations of Mucor species? (2)
allergic reaction (spores); opportunistic infections of skin, sinuses in immunocompromised patients.
Is H. capsulatum found intracellularly or extracellularly?
intracellular (frequently seen inside macrophages)
Identify the major virulence/toxicity factors associated with Stachybotris. (1)
produces a toxin that can cause pulmonary hemorrhage if inhaled.
What is the morphology of Mucor sp/? (2)
mold with irregular non-septate hyphae branching at wide angles (>90 deg). Large fluffy white colonies that turn gray or brown age.
Other than thrush and vulvovaginitis, what other diseases can Candida albicans cause? (2)
disseminated candidiasis (to any organ) and chronic mucocutaneous candidiasis.
Describe the symptoms of Coccidioides immitis infection. (7)
coccidioidomycosis (San Joaquin valley fever)-fever, cough, chest pain, sore throat, hemoptysis. In some patients, conjunctivitis, arthritis, erythema nodosum.
What immune modifying diseases are most commonly associated wit infection with Mucor sp? (2)
ketoacidotic diabetics, leukemic patients
Identify the major virulence/toxicity factors associated with Histoplasma capsulaturm. (1)
Macrophages eat spores which then bud into yeast intracellularly are transported all over the body.
How is a stain of Pneumocystis carinii prepared?
silver stain of lung tissue
What is the morphology of Alternaria?
dark green to brown ‘velvet’ colonies
How does Candida albicans gram stain?
positive
How is Histoplasma capsulatum transmitted?
spores inhaled with dust
What is the major reservoir for Pneumoncystis carinii?
ubiquitous in the environment
What is the major reservoir for Cryptococcus neoformans?
soil
How is superficial fungal infections transmitted?
direct contact with other infected individuals
What are the clinical manifestations of Stachybotris? (4)
nosebleeds, cough, chest congestion, may lead to infection and pulmonary hemorrhage.
How is Pneumocystis carinii transmitted?
inhaled
What is the morphology of Pullalaria?
white-pink colonies turn black as they age
Which pulmonary disease is caused by Aspergillus fumigatus?
lung cavity aspergilloma (fungus ball)
How is Cryptococcus neoformans transmitted?
inhalation of bird droppings (especially pigeon)
Which peptide-containing media is useful for culturing fungi?
sabouraud’s agar
Identify the main risk factor associated with Cryptococcus neoformans.
immunosupressed individual
What are the morphologies of Coccidoides immitis? (2)
mold in soil and spherule in tissues
What is the morphology of Cladosporium?
colonies are powdery, black, brown or dark green.
What are the major reservoirs for Histoplasma capsulatum? (2)
soil (mold form), animal tissues (yeast form).
Are most fungal spores sexual or asexual?
asexual
What lab findings are useful to help diagnose Tinea? (2)
hypae can be seen in skin scraping treated with 10% KOH; will fluoresce under UV light (wood’s lamp)
What disease does C. albicans cause in IV drug users?
endocarditis
What are the clinical manifestations of Histoplasma capsulatum? (5)
histoplasmosis-upper respiratory tract infection may progress to pneumonia with progressive cough, night sweats, weight loss (compare TB). Also painless oral ulcers, hepatosplenomegaly and lymphadenopathy.
What are the clinical manifesations of Rhizopus?
allergy (spores)
What regions are associated with Blastomyces dermatiditis? (2)
found in the Mississippi river valley and parts of Africa
What is the major risk factor associated with cladospourium?
old, wet buildings
Identify relevant epidemiology and risk factors associated with Stachybotris. (2)
infants. cigarette smoke
