Bacterial infections of blood and vasculature Flashcards Preview

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Flashcards in Bacterial infections of blood and vasculature Deck (30)
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1
Q

Borrelia, unlike treponema

A

are large enough to see with standard microscopy

2
Q

B burgdorferi causes

A

Lyme disease, vectored by deer ticks (not dog ticks); with mice and rats preferred by nymphs and deer preferred by adults

3
Q

Lyme diagnosis depends on; serology

A

history of geographic area, season (highest risk in summer when nymphs are feeding) and activity; can confirm exposure but not disease and not promptly

4
Q

Lyme requires

A

about 24 hours to transmit (REMOVE TICK SOONER)

5
Q

Lyme disease has three stages:

A
  1. flulike with erythema migrans rash (bulls-eye appearance in a minority)
  2. Musculoskeletal and/or neurologic symptoms (intermittent arthritis; in Europe, bluish borrelial lymphocytoma and Acrodermatitis Chronica Atrophicans (ACA) on biopsy, a progressive fibrosing skin
  3. Additional neurologic symptoms, also Post-Lyme syndrome with lingering neurological sequelae (chronic progressive encephalomyelitis, subacute encephalopathy);
    worry about COINFECTION with ERLICHIA or BABESIOA meaning high fever
6
Q

Treat Lyme with; give for

A

amoxicillin or doxycycline, alternatives ceftriaxone, cefuroxime axetil;
10-30 days, NO MORE (lingering symptoms due to DAMAGE, NOT lingering bacteria);
Can see Jarisch-Herxheimer reaction and erythema migrans could expand!

7
Q

Relapsing fever may be

A

louse- or tick-borne, louse- is more severe (reservoir is humans; louse crushing and inoculation by scratching), tick- more likely in US (bite of infected tick, usually nocturnal); REPEATED HIGH FEVERS with well periods between, complications of pregnancy

8
Q

Relapsing fever Borrelia

A

immediately enter bloodstream from bite site, repeated rounds of bacteremia and cleanup by IL10+neutralizing Ab’s vs. antigenic variation by spirochete

9
Q

Diagnose relapsing fever by

A

peripheral blood smear; spirochetes are usually visible during febrile periods

10
Q

Treat relapsing fever with

A

tetracyclines (doxy); erythromycin (kids, pregnant women, and adults) and penicillin G in adults

11
Q

Relapsing fever and lyme:

A

avoid ticks (protective clothing, DEET), daily tick checks in at-risk areas in season

12
Q

Successful treatment of any spirochete infection

A

may cause Jarisch-Herxheimer reaction (that and response to treatment may be needed to empirically diagnose Lyme)

13
Q

____, ___, ____ are all what?

A

Rickettsia, Ehrlichia, and Anaplasma; small cocci-to-short-rods are transferred to mammalian hosts by arthropod vectors

14
Q

Rickettsiae are sensitive

A

to tetra (doxycycline)

15
Q

Rickettsiae are ____ parasites and can

A

obligate intracellular; only be grown IN VITRO in tissue culture (like VIRUSES)

16
Q

Rickettsiae diseases present; they can also cause

A

with headache, fever, and body aches; a rash (particularly RMSF, petechial, or epidemic typhus, any) or eschar (particularly Mediterranean Spotted Fever and scrub typhus)

17
Q

For Rickettsiea, proper removal of a potentially-infected tick

A

is with tweezers, while wearing GLOVES, promptly (bacteria take time to transit)

18
Q

Host, reservoir, and uniqueness for epidemic typhus? What’s characteristic of the other rickettsial diseases?

A

Humans are the proper host and reservoir for ONLY epidemic typhus, and is also unique in having a RECRUDESCENT form (Brill-Zinsser disease), VECTORED by body louse;
accidental transmission to humans by promiscuous vectors

19
Q

All four Rickettsiae group (Rickettsia, Coxiella burnetti, Ehrlichia, Anaplasma) replicate

A

within infected cells; Rickettsia divide throughout the cell, Ehrlichia and anaplasma from morulae in phagocytic vacuoles

20
Q

All of the rickettsiae are

A

difficult to stain chemically and require microimmunofluorescent assay to visualize (blood and/or biopsy)

21
Q

Because of the gravity of the Rickettsiae illnesses; alternate treatments for ___ and ____ patients are

A

small children may be treated with tetracyclines but pregnant women are not; pregnant, allergic, use chloramphenicol (Rickettsia) or fluoroquinolones (Ehrlichia, Anaplasma)

22
Q

T/F: B burgdorferi has a definitive test for lyme disease

A

No, there is no definitive lab test (e.g. seropositivity won’t tell much, though seronegativity is relatively reliable)

23
Q

B. burgdorferi prevention includes

A

protective clothing, DEET, avoid woodsy areas, tick collars on pets

24
Q

Rickettsia, Ehrlichia, and Anaplasma are like borrelia and unlike borrelia:

A

Like Borrelia: arthropod vectors, mammalian reservoirs, tetra sens;
unlike Borrelia: small cocci-to-short-rods, intracellular replication

25
Q

RMSF is vectored by

A

ticks

26
Q

RMSF virulence factors include:

A
  1. OmpA&B for adhesion
  2. T4SS: entry
  3. Phospholipase A2: escape from endosome
  4. ActA: actin-based cell-cell spread
27
Q

Epidemic typhus usually begins on

A

trunk and spreads peripherally (the opposite of RMSF which begins on extremities)

28
Q

What season would you expect to see epidemic, murine, and scrub typhus?

A

Cold weather: epidemic;

warm weather: murine and scrub

29
Q

Brill-Zinsser disease risk factors include

A

malnutrition and improper or incomplete antibiotic therapy

30
Q

Ehrlichia (e.g. Human Monocytic ehrlichiosis) and anaplasma (human granulocytic anaplasmosis) can grow

A

within neutrophils