Lecture 5 Part 3: Spirochetes Flashcards
What are the three genera of spirochetes associated with human disease?
Treponema, Borrelia, and Leptospira
What disease is caused by Treponema pallidum?
Syphilis
What disease is caused by Borrelia burgdorferi?
Lyme disease
What disease is caused by Leptospira interrogans?
Leptospirosis
What is the shape and Gram classification of Treponema pallidum?
It is a thin, helical, Gram-negative spirochete
How does Treponema pallidum move?
It has three flagella at each pointed end
What type of environment does Treponema pallidum prefer?
It is either microaerobic or anaerobic
Is Treponema pallidum found in animals or only in humans?
It is a strict human pathogen
TRUE OR FALSE
Treponema pallidum causes venereal (sexually transmitted) disease.
TRUE
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What is the primary stage of syphilis?
It presents as a skin lesion (chancre), survives in phagocytes, and can disseminate
What is the secondary stage of syphilis?
Systemic spread, flu-like symptoms, and a disseminated mucocutaneous rash that is highly contagious
What is the Tertiary stage of syphilis?
A chronic inflammatory condition
What is the shape and Gram classification of Leptospira?
It is a thin, coiled, Gram-negative spirochete with hooks at one or both ends
How does Leptospira move?
It is motile and has two flagella at each end
Where does Leptospira replicate in the host?
It invades and replicates in intact tissues of the host
What is the classification of Leptospira species?
it has a complicated classification, with L. interrogans being pathogenic and L. biflexa being non-pathogenic.
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**What is the difference between a reservoir host and an incidental host for Leptospira?
Reservoir hosts, like rodents and small mammals, are usually asymptomatic, while incidental hosts can become infected after exposure
How is Leptospira transmitted to incidental hosts?
It is spread through water contaminated by infected animals, such as rodents
What causes the damage in Leptospirosis?
Damage mainly due to inflammatory response
What is the typical presentation of Leptospirosis?
Usually mild flu-like disease
What serious complication can occur with Leptospirosis?
Glomerulonephritis
What is Weil disease, and how does it present?
Weil disease is a severe form of Leptospirosis, involving renal and hepatic failure, vascular collapse, and hemorrhage. It can often be fatal.
Is spread to the CNS common in Leptospirosis?
Yes, spread to the CNS is common
How many species of Borrelia are associated with Lyme disease?
3
Which species of Borrelia causes Lyme disease?
The species associated with Lyme disease are B. burgdorferi, B. garinii, and B. afzelii
What is the shape of Borrelia spirochetes?
Large spirochetes
How does the cell wall of Borrelia compare to Gram-negative bacteria?
The cell wall is similar to Gram-negative bacteria but does not stain with Gram stain
What diseases are caused by Borrelia?
Borrelia causes Lyme disease (transmitted by hard ticks) and relapsing fever (transmitted by lice and soft ticks)
Does Borrelia produce toxins?
No, Borrelia does not produce toxins
How does Borrelia cause injury in the host?
The injury is caused by the immune response, specifically proinflammatory cytokines
Does Borellia cause direct damage
**no direct damage* and look at slide 30
Borrelia burgdorferi and Lyme disease
STAGE 1-2
3 – 30 day incubation period
fever, fatigue, arthritis
Borrelia burgdorferi and Lyme disease
STAGE 3
- appears a week to a year after infection
- neurologic symptoms (meningitis, encephalitis, peripheral
neuropathy)
- Cardiac dysfunction (heart block, CHF)
- Arthritis (IgG reactivity to OspA & OspB)
When does Stage 3 of Lyme disease typically appear?
Stage 3 appears a week to a year after infection
What are some symptoms of Stage 3 Lyme disease?
Neurologic symptoms (meningitis, encephalitis, peripheral neuropathy), cardiac dysfunction (heart block, CHF), and arthritis (due to IgG reactivity to OspA and OspB)
What is the characteristic lesion of Stage 1 Lyme disease?
Erythema migrans, a lesion at the site of the bite
What is the incubation period for Borrelia burgdorferi infection (Lyme disease)?
The incubation period is 3 to 30 days
What symptoms occur during Stage 1 and Stage 2 of Lyme disease?
Symptoms include fever, fatigue, and arthritis. The infection persists for about a month on average
