Micro Test 3: Oppotunistic Mycoses

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  1. Name 4 Opportunistic Mycoses (occur in immunocompromised patients)
    • Candidiasis
    • Cryptococcus
    • Aspergillosis
    • Zygomycosis
  2. 2 Main predisposing factors for opportunistic fungal infections
    • 1)  Granulocytopenia
    • 2)  Impaired T-cell mediated immunity
  3. What are the 4 organisms most frequently infecting patients with T-cell dysfunction?
    • Coccidioides (systemic)
    • Cryptococcus
    • Histoplasma (systemic)
    • Candida (mucocutaneous infections only)
  4. 5 disease forms of Candidiasis
    • Thrush
    • Vaginitis
    • Chronic mucocutaneous candidiasis
    • UTI
    • Systemic infection
  5. Which organism is a common cause of disease in the blood?
    Candidiasis (Candidemia)
  6. Candidaisis has a ____ mortality rate.
    high (38%)
  7. Oval yeast with a single bud
    Candida albicans
  8. Candida albicans is seen as an _____
    oval yeast with a single bud

    As opposed to Cryptococcus neoformans, which is seen as an encapsulated oval, budding yeast (pigeon droppings)
  9. Candida albicns form
    pseydohyphase (germ tube)
  10. Dormant spores of C. albicans
  11. Which organism has pseudohyphae and chlamydiospores?
    C. albicans
  12. One of the most common manifestations of HIV infection.
    Is this associated with disseminated candidiasis?
    • Mucocutaneous candidiasis
    • HIV candidiasis involves oropharynx, esophagus, or vagina.
    • No
  13. 3 things that have increased the incidence of Candidiasis.
    • Antimicrobial agents
    • Corticosteroids
    • Central venous access devices
  14. Use of antimicrobial agents, corticosteroids, and central venous access devices have increased the incidence of ____
  15. Candidal endocarditis occurs most commonly in (3 ppl)
    • IV drug users
    • Pts w/ prosthetic heart valves
    • Prolonged use of central venous catheters
  16. IV drug users, patients with prosthetic heart valves, and IV drug users are at an increased risk of developing
    Candidal endocarditis
  17. How do you diagnose disseminated candidiasis?
    CT scan, confirm with biopsy
  18. Candidiasis Tx:  What form?
    Fluconazole, itraconazole
    Amphotericin B
    Fluconazole prophylaxis; risk of resistance
    • OTC:  Vaginitis
    • Azoles
    • AmpB- Systemic Candidiasis infections
  19. Causative agent of Cryptococcis
    • Cryptococcus neoformans
    • Found in pigeon droppings
  20. Cryptococcus neoformans is seen microscoppically as
    Encapsulated oval, budding yeast

    High salt and polysaccharides limits capsule formation!!!
  21. What two things inhibit capsule formation of C. neoformans?
    High salt, polysaccharides

    Once in the lungs, they regenerate their capsules
  22. Name two fungi that are NOT dimorphic.
    • Cryptococcus neoformans
    • Aspergillus fumigatus
  23. C. neoforms causes:
    • Lung infection (often asymptomatic, but may produce pneumonia)
    • Predilection for CSF
    • Meningitis
  24. Which organism has a predilection for CSF and can cause meningitis?
    Cryptoccocus neoformans
  25. Name 3 diseases associated with HIV.
    • Candida albicans- thrush
    • Cryptococcus neoformans- meningitis (90%)
  26. How do you treat Cryptococcus neoformans?
    • AmpB and flucytosine (2 wks)
    • Azoles (8 wks)
    • HIV (therapy for up to a year)
  27. Which organism historically has infections in temperate areas?  (ie. Australia) Infects
    • Cryptococcus gatti
    • Animals and healthy individuals
  28. Cryptococcus gatti historically causes infections in healthy individuals_____ areas.
  29. Cryptococcus gattii (the Aussies) causes:
    • Pneumonia
    • Neurologic involvement
  30. Causative agent of Aspergillosis
    Aspergillus fumigatus
  31. Which organism has septate hyphae and V-branching?
    Aspergilllus fumigatus
  32. Aspergillus fumigatus grows only as a ____.  Is it dimorphic?
    mold, not dimorphic
  33. 2 differentiating factors of A. fumigatus
    • Septate hyphae
    • V-branching
  34. Infectious particle of A. fumigatus
    Radiating conidia
  35. Associated with infections of corneal transplants and fungus balls.
    A. fumigatus
  36. Histoplasmoces can spread from ____ to _____
    Aspergillosis can infect ____ and spread to ________
    • H. capsulatum: lungs to skin
    • A. fumigatus:  skin to body (lungs)
  37. 3 species of Zygomycosis
    Rhizopus, Mucor, Absidia
  38. Saprophytic molds
  39. 4 Disease forms of Zygomycosis
    • Rhinocerebral (nasal passage--> brain)...Like animorphs!!!!
    • Pulmonary
    • Cutaneous
    • GI
  40. Which fungus has an overall mortality rate of > 50% with disseminated disease rates approaching 100%?
  41. 3 Risk factors for Zygomycosis.
    • Diabetic ketoacidosis
    • Burn victims
    • Leukemia
  42. Nonseptate hyphae, broad irregular walls, right angle branching
  43. Aspergillos has a conidiaphore with conidiospores.
    Zygomycosis has a _____ with spores
  44. Facial pain w/ eye protrusion
    Zygomycosis (very rapidly growing)
Card Set:
Micro Test 3: Oppotunistic Mycoses
2012-12-02 22:36:34
Opportunistic Mycoses

Opportunistic Mycoses
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