Rx_01.20 (Microbio) Flashcards

1
Q

Enfurtivide: MOA & use

A
  • antiretroviral therapy
  • MOA = entry inhibitor
    • blocking interaction between gp120 & host CD4 or by interfering w/viral gp41-mediated fusion
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2
Q

Rocky mountain spotted fever presentation

A
  • vacation/travel to South Atlantic states (NC, TN, etc)
  • classic triad = H/A, fever, rash
    • rash = palms/soles/wrists ==> trunk
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3
Q

Rocky Mountain spotted fever cause/spread/tx

A
  • cause = Rickettsia rickettsii
  • spread via ticks =
    • Dermacentor andersoni
    • D. variabilis
  • tx = immediate antibiotic therapy
    • tetracycline (e.g. doxycycline)
    • chloramphenicol
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4
Q

Causes of osteomyelitis in sickle cell patient

A
  • S. aureus
  • Salmonella
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5
Q

Cholera toxin: MOA

A
  • A1 subunit ==> active adenylate cyclase ==> increased cAMP ==> increased chloride ion secretion ==> secretory diarrhea
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6
Q

Hepatitis E presentation + pathology

A
  • Hepatitis E
    • fecal-oral
    • high infection rates @ sub-saharan Africa
    • high mortality in pregnant women
  • Path ==> focal hepatocyte damage ==> patchy necrosis on biopsy
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7
Q

Characteristics of C. albicans

A
  • germ tube-positive fungus
  • ==> white plaques (thrush) @ immunocompromised individuals (common in HIV)
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8
Q

branching rods on culture from pt w/oral infection ==> ? + tx

A
  • Actinomyces israelii
    • gram-positive
    • branching rods
    • anaerobic
    • part of normal oral flora
  • Tx =
    • IV penicillin for 2-6 wks
    • oral penicillin or amoxicillin 6-12 months
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9
Q

Bartonella henseleae causes….?

A
  • cat-scratch fever
    • local, chronic lymphadenitis
    • commonly @ children
  • bacillary angiomatosis
    • usually @ AIDS patients
    • ==> proliferation of blood and lymphatic vessels ==> “mulberry” lesion in skin
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10
Q

Characteristics of Bartonella henselae

A
  • small gram-negative
    • “proteobacterium”
  • visualized w/Warthrin-Starry stain
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11
Q

Rotavirus mechanism of infection

A
  • enters host cell by endocytosis
  • transcribes viral mRNA w/ a viral RNA polymerase present in virion
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12
Q

Presentation of reactive arthritis/”Reiter’s syndrome” + cause

A
  • urethritis, conjuctivitis, arthritis
    • “can’t pee, can’t see, can’t climb a tree”
  • derm sx
    • most plaques on glans penis
    • crusting papules
  • usually male, w/HLA-B27
  • autoimmune rxn post-infection:
    • Chlamydia trachomatis, N. gonorrhoeae
    • Salmonella, Shigella, Yersinia, Campylobacter
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13
Q

Characteristics of Legionella pneumophila pneumonia

A
  • occurs @ older pts w/hx of alcoholism, smoking, DM, chronic illness, immunosuppression
  • legionella =
    • gram-negative rod (coccobaciliary)
    • stains w/silver stain
    • cultures on charcoal yeast extract
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14
Q

Protective factor for HIV infection

A
  • homozygous for CCR5 mutation
    • CCR5 = chemokine receptor on macrophages that facilitates viral entry
  • CCR5 mutation ==> immunity to certain strains of HIV
  • present in primarily caucasian individuals
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15
Q

Common cause of croup + virus type

A
  • cause = paramyxoviridae family (parainfluenza virus)
  • viral characteristics
    • envelope + helical capsid
    • RNA virus
      • single-stranded
      • negative-sense
      • linear, nonsegment
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16
Q

filamentous, gram-positive organism that is weakly acid-fast =

A

Nocardia asteroides

17
Q

Characteristics/tx of Nocardia asteroides

A
  • filamentous, gram-positive
  • weakly acid-fast
  • ==> lung abscesses @ immunocompromised patients
  • Tx =
    • sulfonamides (MOA: inhibition of dihyropteroate synthetase)
18
Q

Yellow fever characteristics

A
  • flavivurs
    • SS, RNA virus
    • mosquito vector
  • sx = H/A, photophobia, MSK pain, jaundice
  • labs/biopsy
    • AST > ALT
    • councilman bodies = eosinophilic degeneration + condensed nuclear chromatin
19
Q

Mechanism of staph scalded skin syndrome

A
  • staph releases (epidermolytic) exotoxins A and B
  • exotoxins bind desmoglein 1 @ desmosome ==> epidermal separation @ stratum granulosum
  • ==> blistering