Borellia & Rickettsiae Flashcards
Other organism that can fit into this category
Yersinia pestis
Borrelia organism size, shape, and visualization
.4um
spirochete (long)
Light microscope visible
Borrelia gran staining
Gram negative
*but NO LPS
Borrelia contains _________ in outer membrane
inflammatory proteins
(OspA + OspC)
B recurrentis and B hermsii cause _____.
Three stages of symptom progession?
Relapsing fever
- General bacteremia (within one week)
- Sudden onset fever, subsides in 3-5 days
- Recurrence of symptoms 5-10 days
Symptom recurrence of B. recurrentis + hermsii caused by _________
Antigenic variation
may go through 5-10 cycles
What is the most common Borellia?
What does it cause?
burgdorfi
Lyme disease
Symptoms of lyme disease (early, and chronic)
Early = Flu-like, erythema chronicum migrans
*Early disseminated symptoms = CN7 palsy, meningitis
Chronic infection = arthritis, joint pain (may affect heart and nerves)
What is behind the pathology of borrelia symptoms?
Autoimmune antibodies
Is borrelia Human > Vector > Human transmission possible?
Only with recurrentis (relapsing fever borrelia)
B. recurrentis spread via ______
human louse
(innoculated when louse is scratched into skin)
B. hermsii is spread via…
soft-bodied ticks from rodent reservoir
(transovarian cycle in the tick)
Many ticks in western US are infected with B. hermsii, but…
outbreaks are rare
B. burgdorferi spread via…
Deer tick nymph (lxodes scapularis)
*from deer, mouse, or bird reservoir
Up to ___% of ticks are infected with B. burgdorferi
50%
Main virulence factor for B. recurrentis + hermsii
antigenic variation
Antigenic variation of borrelia is based on ________
VMP protein antigen
- *Most population has one form, but a few mutants have another one
- *host antibodies select against the mutants
Borrelia (recurrentis and hermsii) latency is when…
relapse is when…
Latency = most of the population has been killed
Relapse = mutant variety grows to repopulate
B.burgdorferi antigenic variation
doesn’t occur
Why do you get multiple rounds of symptoms with burgdorferi if it doesn’t undergo antigenic variation?
Probably a second infection with a different strain of burgdorferi
Preventive control of B. burgdorferi
hygenic delousing
long pants
check body for ticks
Antibiotics for Borellia
Doxycycline or synthetic penicillins
*Can use 3rd gen ceph for recalcitrant (uncooperative) infections
Borrelia vax?
No effective vax
OspA vax developed in 90’s but withdrawn
