Spirochetes

Question 1

What kind of morphology/motility do spirochetes have?

Answer 1

1. Gram negative and anerobic
2. Helically coiled body (spiral shaped)
3. Motile - corkscrew movement

Question 2

Where is the flagella located for spirochetes?

Answer 2

in the periplasm

Question 3

Are all spirochetes pathogenic?

Answer 3

no

Question 4

What are the 3 species/genera of spirochetes that cause human disease?

Answer 4

1. Leptospira species
2. Treponema pallidum (subspecies pallidum)
3. Borrelia burgdorferi

Question 5

What disease do leptospira cause?

Answer 5

Leptosporosis

Question 6

What is an example of a pathogenic leptospira and a non-pathogenic one?

Answer 6

Pathogenic: L. interrogans

Non-pathogenic: L.biflexa

Question 7

What is the natural habitat for Leptospira sp.?

Answer 7

stagnant fresh water

Question 8

What growth conditions do Leptospira favour?

Answer 8

higher temperatures

- see it more in the summer months

Question 9

What is the geographical/time distribution of Leptospirosis cases?

Answer 9

usually occur in tropical areas

outside of tropical areas, the distribution of cases is seasonal (usually)
- typically occurring in Aug-Sep

Question 10

Leptospirosis is a zoonotic disease. What is the primary host? what are humans?

Answer 10

Primary host: rodents

Humans: accidental hosts

Question 11

What other animals can be infected with Leptospirosis?

Answer 11

trick question! pretty much any animal, wild or domestic

Question 12

How do humans become infected with Leptospirosis?

Answer 12

ingestion or contact with water/soil contaminated by animal urine
- through breaks in the skin or mucous membranes

Question 13

Why is the diagnosis of leptospirosis often missed?

Answer 13

Because there can be a wide range of symptoms

• flu like symptoms
• can also mimic other diseases as it progresses

Question 14

What 3 antibiotics can be used to treat leptospirosis?

Answer 14

1. Aminoglycosides
2. Doxycycline
3. ß-lactams

Question 15

What is the timeline of where the spirochetes can be found in the body for leptospirosis?

Answer 15

1. First 7-10 days they can be found in the blood
   - leptospiremia
2. After this they move to the kidneys and are found in the urine

Question 16

Why is culture not really used to diagnose leptospirosis in the lab?

Answer 16

Because you need a very special media and it takes about 3 months to generate a positive/negative results

Question 17

What is the go to lab method used to diagnose leptospirosis?

Answer 17

Serology - looking for IgM and IgG responses

Sometimes will also do PCR on blood or urine depending on the timing

Question 18

In the treponema genus, how many are human pathogens?

Answer 18

4

Question 19

Which species of treponema causes syphilis?

Answer 19

T. pallidum subsp. pallidum

Question 20

What are the 4 stages of syphilis? what is a characteristic symptom of each?

Answer 20

1. Primary - chancre and lymphadenopathy
2. Secondary - rash
3. Latent - asymptomatic
4. Tertiary - cardiovascular, neurological issues or gumma

Question 21

What is the chancre like? is it infectious?

Answer 21

painless ulcer with sharp borders and clean base

contact leads to infection in >50% of cases

Question 22

What is the presentation of the rash like in syphilis? What is distinctive?

Answer 22

Can present variably - diffuse, maculopapular, pustular

Question 23

What is the lab-diagnosis definition of latent syphilis?

Answer 23

having serological proof of infection without symptoms of disease

Question 24

What is the differentiation between early and late latent syphilis?

Answer 24

1. Early latent: less than a year after secondary syphilis

2. Late latent: greater than 1 year after secondary syphilis

Question 25

What are the 3 potential presentations of tertiary syphilis?

Answer 25

1. Gummatous syphilis - soft, tumour-like balls of inflammation in the skin, bone liver etc. 2. Neurosyphilis 3. Cardiovascular syphilis

Question 26

What are the 2 days that syphilis can be transmitted?

Answer 26

1. Sexual contact | 2. Vertical transmission

Question 27

Vertical transmission of syphilis often results in?

Answer 27

miscarriage and stillbirth

Question 28

What are some early vs. late symptoms of congenital syphilis?

Answer 28

Early: kind of looks like an RTI at birth - rash, fever, pneumonitis, hepatosplenomegaly Late: if untreated - saddle nose, clutton's joints, saber shin, hutchinson teeth

Question 29

What is the treatment for syphilis?

Answer 29

IM or IV penicillin - not the typical kind - Benzathine (IM) - PenG (IV)

Question 30

When is IV PenG given?

Answer 30

for neurosyphilis

Question 31

What can be given as an alternate drug treatment for syphilis if the patient is allergic to penicillin?

Answer 31

Doxycycline

Question 32

Can you culture syphilis?

Answer 32

Not on artificial media Used to use a rabbit infectivity test (RIT)

Question 33

What is the main diagnostic tool used for syphilis?

Answer 33

serology

Question 34

What are the two types of serological tests used for syphilis?

Answer 34

non-treponemal and treponemal

Question 35

What is another name for non-treponemal tests?

Answer 35

flocculation test

Question 36

How do non-treponemal tests work? what type of test are they

Answer 36

Agglutination type test 1. Treponemes induce damage to host cell 2. Body then produces anti-cardiolipin antibodies 3. These interact with lecithin-cholesterol-cardiolipin

Question 37

What are 2 examples of non-treponemal tests?

Answer 37

1. Rapid Plasma Reagin (RPR) | 2. Venereal Disease Research Lab test (VDRL)

Question 38

What are the disadvantages of non-treponemal tests?

Answer 38

1. Insensitive early and late in disease 2. False positive reactions can occur so you always need to do a confirmatory test - ex: in an area with other endemic treponemes, endocarditis, pregnant...

Question 39

Non-treponemal rests are the most sensitive at detecting which stage of syphilis?

Answer 39

secondary stage

Question 40

What are 2 advantages to non-treponemal serological testing?

Answer 40

1. Rapid, inexpensive, and easy to perform - qualitative 2. Quantitative in that it can be used to measure response to therapy

Question 41

What are treponemal tests measuring?

Answer 41

Measure antibody directed against T. pallidum antigens

Question 42

What are 4 examples of treponemal tests? Which one would you use first?

Answer 42

1. EIA - would probably use this first because of IgM capture but you can get false positives 2. Fluorescent treponemal antibody absorbed (FTA-ABS) 3. T.pallidum particle agglutination (TPPA) 4. Recombination immunoblot

Question 43

What are some disadvantaged to treponemal testing?

Answer 43

1. People are reactive for life, even after treatment - can't use it to monitor treatment 2. False positives can still occur 3. False negatives can also occur

Question 44

What is the current testing algorithm for syphilis?

Answer 44

1. Do an EIA IgM screening (treponemal test) - if negative = no syphilis 2. If EIA +, do a second treponemal test (TPPA) - if this one was negative it indicates: 1. had it but have been treated successfully 2. early of late latent stage 3. False positive EIA - would then do an immunoblot/FTA-ABS 3. If + for both the EIA and the TPPA, move on to doing a non-treponemal RPR titre test