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23 Cards in this Set
- Front
- Back
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cryptococcus main manifestation esp in immunocomp
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meningitis
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blastomyces geographical association?
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mississippi/ohio river valley
(picture rocket Hitting and blasting the Mississippi river valley) |
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histoplasma geographical association?
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mississippi/ohio river valley
(picture rocket Hitting and blasting the Mississippi river valley) |
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coccidioides geographical association?
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southwestern USA, mexico, south/central america
(picture southern cowboy “cocking” his spore-gun) |
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5 reasons why histoplasma, blastomyces and coccidiodes are like TB
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1) infection via inhalation
2) primary manifestation is pneumonia 3) can disseminate to other organs 4) can have granulomas, calcifications and/or cavitations 5) skin test is like PPD |
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treatment for histoplasma, blastomyces and coccidioides?
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histoplasma and coccidioides usually are mild and so are not treated. Blastomyces is usually severe and is thus treated aggressively with itraconazole or amphotericin B for months
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What is a reservoir for histoplasma?
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bird/bat droppings
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what is a reservoir for blastomyces?
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soil and rotting wood
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what is a reservoir for cryptococcus neoformans?
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pigeon droppings
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What is the coccidioides tissue phase?
what is its life cycle from inhalation to regeneration of the original form |
a spherule instead of a yeast,
Inhalation of arthroconidia --> Arthroconidia transform into spherule in the lung. At maturity, spherules produce endospores. Rupture of spherule releases endospores --> which in turn form new spherules |
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What do patients with penicillosis marneffei present with? and where is it found (geographically)?
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fever, malaise, skin lesions, lymphadenopathy, organomegaly, anemia, leukopenia, thrombocytopenia and cytopenias
found in thailand and southern China |
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What are dermatophytes responsible for superficial cutaneous infections?
how are they treated? |
MET: microsporum, epidermophyton, trichophyton
treated with imidazoles and griseofulvin if infection is scalp/nails (keratin) |
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What causes sporotrichosis? how does it develop?
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sporothrix schenkii - found in soil and on plants (thorns, splinters).
Pricked by thorn --> subcutaneous nodules --> necrotic and ulcerates --> ulcer heals but new nodules pop up along lymphatic tracts up arm |
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What causes chromoblastomycosis and where are they found? What is disease process?
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Phialophora and Cladosporium (found on rotting wood)
it is a subcutaneous infection: puncture wound --> infection --> small violet wartlike lesions --> additional lesions over months-years (resemble cauliflower) |
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what are the forms of conidia that histoplasma mold produces?
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tuberculate macroconidia - big so it doesnt get into terminal alveoli
microconidia - problematic because theyre small, so get into terminal alveoli --> phagocytosis by pmns/macros --> converts to yeast form |
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What is more importnat in combating systemic mycoses - antibodies or CMI?
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CMI!!!!-- thats why AIDS patients have such susceptibility to them
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what fungus are antibodies most important against?
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cryptococcus neoformans! because it has a mucopolysaccharide capsule that creates a negative charge around the yeast and prevents phagocytosis
antibodies allow opsonization and phagocytosis |
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What does aspergillosis cause in a normal host? in an immunocompromised host?
When does aspergilloma form? What is bronchopulmonary aspergillosis? |
Chronic necrotizing aspergillosis in normal hosts; invasive pulmonary aspergillosis in immunocompromised, neutropenic hosts
Aspergilloma forms within a cavity in lung that might have been due to other problem (like TB) bronchopulmonary aspergillosis is IgE mediated allergic reaction to aspergillus flavus' fungal antigens |
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what form(s) does aspergillus flavus exist in?
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Only exists in hyphal (septate) form -- its a monomorphic mold
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What happens when aspergillus disseminates via blood? what about cryptococcus?
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When aspergillus disseminates it goes to brain and causes abscesses. Cryptococcus causes meningitis
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why do you get tissue infarction with aspergillosis
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aspergillosis is angioinvasive, it likes to invade blood vessels
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what do zygomycoses look like under the microscope? What about aspergillus?
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Zygomycoses look like mold with irregularly contoured ASEPTATE hyphae.
Aspergillus looks like mold with SEPTATE hyphae |
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What type of fungal infection occurs in ketoacidotic diabetics and leukemic patients?
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Zygomycosis: Mucor and Rhizopus infections -->Zygomycosis: mold with irregular nonseptate hyphae branching at wide angles (>90).
Causes: Rhinocerebral zygomycosis: Rhinocerebral and frontal lobe abscesses. (occurs in ketoacidotic diabetics/leukemics) Pulmonary zygomycosis: Fungi also proliferate in walls of blood vessels and cause infarction of different tissues (similar to aspergillosis) |
