systemic spirochetes Flashcards
characteristics of spirochetes
spiral shaped
corkscrew motility
DONT gram stain
grow slow or not at all
three genuses that are pathogenic spirochetes
treponema - all identical, with same serological response, and susceptible to penicillin
borrelia - zoonotic
leptospira - zoonotic
are treponema susceptible to penicillins?
yes
T pallidum - can it grow in culture?
No
vector/transmission of lyme disease
Tick borne —-Northeast and Midwest = Ixodes scapularis (also called Ixodes dammini) or B. burgdorferi —nymph stage transmits infection (May through July). —White-footed mice and white-tailed deer are important for the life cycle of these ticks
local spread of lyme disease (primary lesion) is
erythema migrans
pathogenesis of lyme disease
•Early infection: stage 1 (localized infection; days to weeks) - characterized by erythema migrans at site of tick bite
stage 2 (disseminated infection; weeks to months) - characterized by secondary annular skin lesions and systemic symptoms such as severe malaise and fatigue. Bell’s palsy
—carditis, meningitis, arthritis
•Late infection: stage 3 (persistent infection; months to years) - characterized by arthritis, meningoencephalitis, neuropathies
bells palsy
loss of muscle tone on one or both sides of the face
–occurs with lyme disease
oral antibiotic for lyme disease?
doxycycline
(a tetracycline - used for lyme and anthrax)
STARI
Southern Tick-Associated Rash Illness (STARI)
similar to the rash of Lyme disease, associated with the bite of the lone star tick, Amblyomma americanum. This Lyme disease-like rash has been named Southern tick-associated rash illness (STARI).
relapsing fever
caused by borrelia species
vector = louse (human reservoir) or tick (animal host)
characterized by recurrent episodes of fever separated by asymptomatic intervals
borrelia recurrentis
louse borne relapsing fever
transmitted by lice; no animal reservoir
occurs in epidemics
borrelia hermsii
tick borne relapsing fever
YES animal reservoirs; occurs in endemic (not epidemic) forms
what form of relapsing fever more often shoes jaundice and CNS involvement….
louse borne
leptospirosis
caused by spirochete leptospira
an acute febrile illness with conjunctival suffusion (reddened conjunctiva due to blood flow) and renal failure (Weils disease) and/or meningitis