Infectious Lymphadenopathy Microbiology

  1. Not only are cats evil, but their stupid little scratches can also make you develop this:
    • Cervical lymphadenopathy
    • Axillary lymphadenopathy
    • Bottom line is, stay away from cats
  2. Tularemia is caused by this bug:
    Francisella tularensis
  3. Gram stain/ shape of Francisella tularensis:
    • Gr -
    • Pleomorphic Rods
  4. Which biotype (A or B) of Francisella tularensis is more virulent in the USA?
    • Type A
    • Found in rabbits, deer, rodents
  5. Human cases of Francisella tularensis infection is found mostly in which part of US?
    • Missouri
    • Arkansas
  6. #1 vector of Francisella tularensis?
    Ticks (Dermacentor feeds on them rabbits)
  7. T/F: Humans are the accidental dead end host of Francisella tularensis
  8. T/F: Tularemia can be transmitted via bite or inhalation
    True, though inhalation/ ingestion is rare
  9. How is the bacteria transmitted in ticks?
    Adult ticks are capable of transmitting the infection by passing it to its offspring via transovarian route
  10. Notable cutaneous tularemia syndrome is:
    Ulceroglandular- skin papule followed by ulcer and tender lymph adenopathy
  11. T/F: Tularemia skin lesion is typically black and non-painful
    False; tularemia skin lesion is usually a red papule and it is tender, Anthrax is black and non-painful
  12. After Francisella tularensis enters through the skin, where does it localize to?
    Reticuloendthelial system- causing disintegration of macrophage membrane
  13. T/F: Francisella tularensis exotoxins are what is causing symptoms of tularemia
    False; its endotoxin
  14. What is the primary intracellular target of F. tularensis?
  15. T/F: tularemia have a pulmonary form- often sudden onset and influenza like
    True, this is through breathing in- so rare
  16. T/F: definitive diagnosis of Tularemia is through culturing
    • False; culturing is rarely done because this is high risk to the lab workers
    • Also because it requires a cysteine medium that is not really available
  17. What is the definitive diagnosis of tularemia?
    Agglutination test, looking for antibodies
  18. Is there vaccine available for F tularensis?
    Yes, but only for people at highest risk
  19. Evil cat’s name is ___
    • Bart
    • Bartonella henselae is the bug that causes cat scratch disease
  20. What is so terrible about Bartonella henselae especially in immunocompromised people?
    Can develop bacillary angiomatosis
  21. Gr stain and shape of Bartonella henselae?
    • Gr negative
    • Pleomorphic rod
  22. T/F: Bartonella will grow on routine blood agar
    False, they are fastidious
  23. Reservoir of Bartonella?
  24. What can Bartonella cause in immunocompetent people? Immunocompromised?
    • competent: febrile lymphadenopathy
    • Compromised: bacillary angiomatosis
  25. T/F: Bartonella is transmitted from flea to cat during feeding
    False; bartonella is not transmitted through the flea saliva, instead it is through their poop
  26. Bacillary angiomatosis is characterized by this clinical presentation:
    Raised, cherry-red vascular lesions in the skin and visceral organs that looks kinda like Kaposi’s sarcoma (which is HIV related)
  27. Bacillary peliosis is usually lesions in ________?
    Liver and spleen
  28. How is Bartonella diagnosed?
    • Pleomorphic rods seen in biopsy tissue
    • Warthin-Starry silver stain
  29. What is the stain used for Bartonella biopsy?
    Warthin-Starry silver stain
  30. How to treat cat scratch disease?
    • Well, if immnocompetent, just deal with it, unless its bad then maybe you some Azithromycin (macrolide)
    • If immunocomprised and were treating Bacillary angiomatosis, use tetracycline (doxy) or macrolide (erythromycin)
  31. Brucella shape and gram stain and does it have capsule?
    • Gr negative
    • Rods
    • No capsule
  32. Arthropod vector for Brucella?
    Trick question! There isn’t one
  33. How is Burcellosis transmitted?
    Eating or drinking animal stuff
  34. Where does brucella live inside the body?
  35. T/F: exotoxins are produced in Brucella
    False just endotoxin because of Gr negative = LPS
  36. Pt who is a farmer presents with on and off fever pattern and enlarged lymph nodes on exam. What is the bug and what else could be found clinically?
    • Brucella
    • Hepatosplenomegaly
    • Pancytopenia
  37. What is the most common complication with B. melitensis infection?
  38. T/F: brucella can be cultured on cysteine enriched media
    False; brucella can be cultured, but on media that is enriched with 10% CO2 (cysteine agar is for Francisella, but that is almost never cultured)
  39. Black plague is caused by_____
    Yersinia pestis
  40. Yersinia pestis gram stain, shape and does it have capsule?
    • Gr negative
    • Rod with bipolar staining (red at ends)
    • Has capsule- polysaccharide-protein complex
    • Non motile
  41. How is the black plaque transmitted?
    infected fleas with thick biofilm on its upper GI tract eat humans- accidental hosts
  42. Reservoir of Yersenia
    Urban rats
  43. Bug with V and W antigen and an envelope capsular antigen (F1):
    Yersinia pestis
  44. Which bug can inject YopS proteins to host cells which dampen host immune response
    Yersinia pestis – causing pneumonic plague
  45. Anthrax is Gram ______, ______ (shape), ________ (motility), _______ (spore?), _______ (capsule?)
    • Gram positive
    • Chained Rods
    • Non-motile
    • Spore-forming
    • Large Poly-D glutamate capsule
  46. Black echar on exam:
  47. How can Anthrax be transmitted?
    • inhaled the spores
    • Ingest the spores
  48. Edema factor and Lethal factor are toxins made by which bug?
  49. T/F: Anthrax has exotoxins
    True; edema factor, lethal factor and protective antigen
  50. Which of the anthrax exotoxin (AB toxin) is part of the A subunit that increases intracellular cAMP?
    Edema Factor
  51. Which of the anthrax AB toxin is part of the A subunit that cleaves phosphokinase of the MAPK signaling pathway which inhibit cell growth
    Lethal factor
  52. What is protective antigen?
    An anthrax exotoxin, of the B subunit for both EF and LF, binds to cells for A subunit internalization = aka lets the EF and LF toxins into cells
  53. Which bug can cause rapid hemorrhagic mediastinitis?
  54. Widening of mediastinum on xray is diagnostic criteria for which bug?
    Inhalation anthrax
  55. Acute febrile tick-born diseases:
    • Ehrlichia
    • Anaplasma
  56. Ehrlichia targets ____ cells while anaplasma targets ________ cell
    • Monocytes
    • Neutrophils
  57. T/F: ehrlichia and anaplasma are obligate intracellular gram negative rods without LPS or peptidoglycan
  58. Vectors and reservoirs for E chaffeensis (ehrlichiosis)
    • Ticks – vectors
    • White-tailed deer – reservoir
  59. Ehrlichosis usually occur in which months?
    Summer/ warm months
  60. Which of the acute febrile tick borne disease can have brain involvement?
    • Ehrlichiosis
    • Late illness can have damage to the brain resulting in meningoencephalitis
  61. Ehrlichiosis is often in _____ region and anaplasmosis in ______
    • Missouri, Arkansas, new York, virginia
    • Northeast, Wisconsin, Minnesota
  62. Look for ‘morulae’ in blood smears for which organisms?
    Ehrlichiosis and anaplasmosis
  63. Chagas disease is caused by ___
    Trpansoma cruzi (a flagellated protozoan)
  64. What is the vector for T. cruzi? Reservoir?
    • Reduviid bug
    • Reservoir is humans and animals
  65. How is T cruzi transmitted in human?
    Infected Reduviid bug (vector) has trpomastigotes in their guts and that gets into our blood in the form of bug feces when the but bites
  66. In us, T cruzi is in this form:
    Nonflagellated amastigotes
  67. Where is Chagas disease often found?
    Central and south America
  68. Which bug can cause myocarditis and congestive heart failure?
    T cruzi (chronic Chagas disease of which there is no effective drug against)
  69. What is Romana’s sign?
    Swelling of one of the eyes as seen in Chagas disease (caused by Trypanosoma cruzi)
  70. Which of the Trypanosoma species causes African Sleeping sickness which has CNS involvement (think demyelinating encephalitis)
    Trypanosoma brucei
  71. What is the vector of T brucei? Reservoir?
    • Tsetse fly
    • Reservoir: humans
  72. Which of the Trypanosoma species form a metacyclic trypomastigotes form?
    T brucei. (this form is transmitted via tsetse fly bite)
  73. T/F: Tsetse fly injects the infectious metacyclic trpomastigotes form of T brucei via poop into human bloodstream
    False; all is true except that tsetse fly infect through their saliva into our skin
  74. T/F: T brucei are often found as amastigotes in tissue, much like T. cruzi and leishmania
    False; T brucei are rarely found as amastigotes, unlike T cruzi and leishmania
  75. How does T brucei (African sleeping sickness) evade our immune system?
    It has variable surface glycoprotein which basically means that their glycoprotein coat and change every 10 days – this also results in a cyclical fever spike
  76. What is Winterbottoms sign?
    • Posterior cervical lymph nodes
    • African Sleeping Sickness (T brucei)
  77. T brucei gambiense can induce ____ over a few years, T brucei rhodesiense can cause ______ if untreated. (these are both subspecies of African sleeping sickness)
    • Low grade chronic course
    • Death
  78. Use ELISA to detect IgM antibody in early _____ infection
    African Slepeing sickness
  79. _____ is a drug that should be initiated before development of the third starge encephalitis caused by T brucei (African sleeping sickness)
    Suramin (does not cross BBB)
Card Set
Infectious Lymphadenopathy Microbiology
HemeOnc Midterm 2