Test 2 Micro

  1. What genus has mycolic acid in their cell wall, but isn't acid fast?
  2. What genus has metachromatic granules within their cells?
    What stain do you use to see these?
    • Corynebacterium
    • Methylene blue
  3. Corynebacterium diphtheriae
    • Aerobic
    • Non-motile
  4. What type of toxin is Diphtheria toxin?
    What gene carries this toxin and how is it transmitted?
    Synthesis of this gene is regulated by?
    • A-B toxin
    • Tox gene carried by lyosgenic phase
    • Synthesis is regulated by DTxR
  5. Diptheria toxin gene synthesis, stimulated or repressed by high iron levels?
    Repressed by high iron levels
  6. Which subunit of Corynebacterium diptheria  is the recptor-binding and translocation region?
    Subunit B (allows movement of catalytic A region into host cell cytosol)
  7. Terminates host cell protein synthesis by inactivating elongation factor 2 (EF-2)
    Subunit A of Corynebacterium diptheriae
  8. Thich pseudomembrane develops over pharynx in?
    Respiratory Disease (Corynebacterium diptheriae)
  9. Culture Corynebacterium diptheriae on?
    Blood agar, cysteine-tellurite agar
  10. Elek Test
    Used to test for Corynebacterium diptheriae.  Involves antitoxin-soaked filter paper and an X.... Ask Sam
  11. Once diptheria toxin is internalized, _______.
    What can stop diptheria toxin from binding to cells?
    • cell death is inevitable (think of a bull being released in cell)
    • DAT (diptheria antitoxin)
  12. Diptheria toxin is treated with ______.  This messes up the toxin's ability to _________.
    • formalin
    • bind the receptor
  13. Aerobic Actinomycetes:
    Gram-P or Gram-N?
    Enzyme positive for?
    Some have filamentous forms
    Weakly-acid fast
    • Gram-P rods
    • Catalase-P
  14. Name 2 types of Actinomycetes.
    • Nocardia
    • Rhodococcus
  15. Which typ of actinomycetes is a strict aerobe?
  16. Aerial hypae found on the colonies of?
  17. What factor of Nocardia facilitates intracellular survival by blocking fusion of phagosomes with lysosomes?
    Cord factor
  18. Suppurative granulomas, progressive fibrosis and necrosis, and sinus tract formation
    Mycetoma (Nocardia)
  19. Granuloma formation and erythematous subcutaneous nodules with eventual ulceration.
    Lymphocutaneous disease (Nocardia)
  20. Granulomatous ulcers with surrounding erythema; little involvement of draining lymph nodes.
    Cellulitis and subcutaneous abscesses (Nocardia)
  21. Can present initially as chronic meningitis.
    Nocardia (CNS infections)
  22. Salmon-pink pigment?
    Rhodococcus (also aerobic)
  23. Facultative intracellular organism survives in macrophages and causes granulomatous lesion with abscess. (Originally considered an occupational pathogen of farmers and veterinarians)
    Rhodococcus equi
  24. Actinomycetes Diseases (not already listed)
    • Exudative dermatitis
    • Whipple's Disase
    • Allergic pnemonitis (farmer's lung)
  25. What bacteria give you farmer's lung?
  26. 2 enzymes that inactivate toxic oxygen metabolites for Nocardia.
    Catalase, SOD
  27. Infection intrinsic to the skin
    Primary skin infection
  28. Systemic or other organ dysfunction manifested in the skin.
    Secondary skin infection
  29. Which disease affects the stratum corneum?
  30. Name 1 disease that affects the epidermis.
  31. Name 2 diseases that affect the dermis.
    • Erysipelas
    • Cellulitis
  32. Necrotic tropical ulcer affects what layer?
    Fat (If I go to a tropical resort, I get fat.)
  33. Necrotizing fasciitis affects what layer?
  34. Name 1 disease that affects the muscle layer.
  35. Name a complication of Impetigo.
    Post-streptococal glomerulonephritis
  36. Superficial bacterial infection of hair follicles within the epidermis: usually localized.

    What organism causes this?
    • Folliculitis
    • S. aureus
  37. Pathogen and tx of Hot Tub Folliculitis.
    • Pseudomonas
    • No tx required
  38. Infection of hair follicles extending into subcutaneous tissue. (boil or risin)
  39. Serious deep-seated infection involving several hair follicles.
    Carbuncles (Carbs provide lots of energy to spread to multiple hair follicles :-)
  40. Acute inflammatory, superficial infection of lower legs, face, or ears
    Erysipelas (basically swelling)
  41. Most Erysipelas is caused by?
    S. pyogenes (though S. aureus can cause some)
  42. Treat Erysipelas with?
    1st Gen. Cephalosporin
  43. Red swollen ear.
    Otitis externa
  44. Expanding red, swollen, hot, tender plaque w/ indefinite border
  45. Necrosis (skin is dusky blue to black and bullae are often present)
    Primary Pyyoderms: Necrotizing soft tissue infection (SURGICAL EMERGENCY!)
  46. How do you treat necrotizing fasciitis?
    • Multiple debridements
    • Clindamycin + ampicillin + metronidazole
    • Clindamycin +piperacillin/tazobactam
Card Set
Test 2 Micro
Corynebacterium, Nocardia, Soft Tissue Infections