Lecture 5 Part 3: Spirochetes

Question 1

What are the three genera of spirochetes associated with human disease?

Answer 1

Treponema, Borrelia, and Leptospira

Question 2

What disease is caused by Treponema pallidum?

Answer 2

Syphilis

Question 3

What disease is caused by Borrelia burgdorferi?

Answer 3

Lyme disease

Question 4

What disease is caused by Leptospira interrogans?

Answer 4

Leptospirosis

Question 5

What is the shape and Gram classification of Treponema pallidum?

Answer 5

It is a thin, helical, Gram-negative spirochete

Question 6

How does Treponema pallidum move?

Answer 6

It has three flagella at each pointed end

Question 7

What type of environment does Treponema pallidum prefer?

Answer 7

It is either microaerobic or anaerobic

Question 8

Is Treponema pallidum found in animals or only in humans?

Answer 8

It is a strict human pathogen

Question 9

TRUE OR FALSE
Treponema pallidum causes venereal (sexually transmitted) disease.

Answer 9

TRUE

Question 10

**

What is the primary stage of syphilis?

Answer 10

It presents as a skin lesion (chancre), survives in phagocytes, and can disseminate

Question 11

What is the secondary stage of syphilis?

Answer 11

Systemic spread, flu-like symptoms, and a disseminated mucocutaneous rash that is highly contagious

Question 12

What is the Tertiary stage of syphilis?

Answer 12

A chronic inflammatory condition

Question 13

What is the shape and Gram classification of Leptospira?

Answer 13

It is a thin, coiled, Gram-negative spirochete with hooks at one or both ends

Question 14

How does Leptospira move?

Answer 14

It is motile and has two flagella at each end

Question 15

Where does Leptospira replicate in the host?

Answer 15

It invades and replicates in intact tissues of the host

Question 16

What is the classification of Leptospira species?

Answer 16

it has a complicated classification, with L. interrogans being pathogenic and L. biflexa being non-pathogenic.

Question 17

**

**What is the difference between a reservoir host and an incidental host for Leptospira?

Answer 17

Reservoir hosts, like rodents and small mammals, are usually asymptomatic, while incidental hosts can become infected after exposure

Question 18

How is Leptospira transmitted to incidental hosts?

Answer 18

It is spread through water contaminated by infected animals, such as rodents

Question 19

What causes the damage in Leptospirosis?

Answer 19

Damage mainly due to inflammatory response

Question 20

What is the typical presentation of Leptospirosis?

Answer 20

Usually mild flu-like disease

Question 21

What serious complication can occur with Leptospirosis?

Answer 21

Glomerulonephritis

Question 22

What is Weil disease, and how does it present?

Answer 22

Weil disease is a severe form of Leptospirosis, involving renal and hepatic failure, vascular collapse, and hemorrhage. It can often be fatal.

Question 23

Is spread to the CNS common in Leptospirosis?

Answer 23

Yes, spread to the CNS is common

Question 24

How many species of Borrelia are associated with Lyme disease?

Answer 24

3

Question 25

Which species of Borrelia causes Lyme disease?

Answer 25

The species associated with Lyme disease are B. burgdorferi, B. garinii, and B. afzelii

Question 26

What is the shape of Borrelia spirochetes?

Answer 26

Large spirochetes

Question 27

How does the cell wall of Borrelia compare to Gram-negative bacteria?

Answer 27

The cell wall is similar to Gram-negative bacteria but does not stain with Gram stain

Question 28

**What diseases are caused by Borrelia?**

Answer 28

**Borrelia causes Lyme disease (transmitted by hard ticks) and relapsing fever (transmitted by lice and soft ticks)**

Question 29

**Does Borrelia produce toxins?**

Answer 29

**No, Borrelia does not produce toxins**

Question 30

**How does Borrelia cause injury in the host?**

Answer 30

**The injury is caused by the immune response, specifically proinflammatory cytokines**

Question 31

**Does Borellia cause direct damage**

Answer 31

**no direct damage* and **look at slide 30**

Question 32

**Borrelia burgdorferi and Lyme disease STAGE 1-2**

Answer 32

**3 – 30 day incubation period fever, fatigue, arthritis**

Question 33

**Borrelia burgdorferi and Lyme disease STAGE 3**

Answer 33

**- 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)**

Question 34

**When does Stage 3 of Lyme disease typically appear?**

Answer 34

**Stage 3 appears a week to a year after infection**

Question 35

**What are some symptoms of Stage 3 Lyme disease?**

Answer 35

**Neurologic symptoms (meningitis, encephalitis, peripheral neuropathy), cardiac dysfunction (heart block, CHF), and arthritis (due to IgG reactivity to OspA and OspB)**

Question 36

What is the characteristic lesion of Stage 1 Lyme disease?

Answer 36

Erythema migrans, a lesion at the site of the bite

Question 36

**What is the incubation period for Borrelia burgdorferi infection (Lyme disease)?**

Answer 36

**The incubation period is 3 to 30 days**

Question 37

**What symptoms occur during Stage 1 and Stage 2 of Lyme disease?**

Answer 37

**Symptoms include fever, fatigue, and arthritis.** The infection persists for about a month on average