Spirochetes Flashcards
Describe the morphology of spirochetes
gram negative, helicoid bacteria (think corkscrew)
Is spirochetes motile?
yes! It’s one of the fastest bacteria!
Describe the three major genera of spirochetes
- Treponema=syphilis
- Borrelia=lyme disease
- Leptospira
What does treponema look like on a gram stain?
Cannot see it on a gram stain. It is too small
What techniques can you use to visualize treponema?
- dark field stain
- immunofluorescence
- silver salts
- electron microscope
Can you culture treponema?
No. Cannot survive in the blood after several days. Therefore, cannot get syphilis from a blood transfusion.
However, you can keep them motile under anaerobic conditions and rich media
What are the different stages of syphilis?
- Bacterial replication at infection site
- Primary lesion that heals spontaneously
- Secondary syphilis: Dissemination to rash, arthritis, renal dysfunction. May see sore throat, malaise, skin lesions on face, palms, soles
- Tertiary lesions: Occurs many years later. Includes CNS, aortic aneurysms, hypersensitivity lesions
How would you diagnose syphilis?
- Serologic tests
2. Specific tests
Describe the various serologic tests for syphilis:
- Wasserman: antibody interacts with cardiolipin
- VDRL (venereal disease research laboratory test)
- Rapid plasma reagent (clumping of antigen on carbon particles)
Describe the various specific tests for syphilis
- Fluorescent treponemal antibody absorption
- Microhemmaglutination test
- ELISA
- T. pallidum immobilization test
How is treponema currently being tested for?
- Direct microscopic exam
- Non-treponemal specific tests
- Treponemal specific tests
- ELISA
can treponema be cultured?
no
can syphilis be transmitted through a blood transfusion?
no, unless it’s very fresh blood
How is syphilis transmitted?
- direct genital contact
- congenital syphilis–can result in stillbirth or abortion
- transfusion if blood if very fresh
What are the three stages of syphilis?
- bacterial replication at infetion site
- primary lesion, heals spontaneously
- Secondary lesion: Dissemination to rash on hands/palms, arthritis, renal dysfunction. sore throat malaise
- Tertiary lesion: CNS, aortic valves, hypersensitivity MANY YEARS LATER. Not many organisms seen.
Diagnosis and testing of syphilis?
Check micro notes
What are the benefits of nontreponemal tests?
High sensitivity with lots of false positives. Also possible cross reaction and failure of titers to decline
How does the microhemagglutination test work?
Tests for treponemal antibodies
How do you treat syphilis?
Penicillin.
If allergic to penicillin, can use tetracycline or erythromycin
What are other treponemal diseases?
- Yaws
- bejec
- pinta
What causes relapsing fever?
Borrelia hervisii and borellia recurrentis
How are the two different borrelia pathogens of relapsing fever transmitted?
B Hernsii transmitted by ticks
B recurrentis transmitted by body louse
What are the symptoms of borrelia relapsing fever?
Fever, afebrile, relapse. Varies surface antigen frequently, which is encoded on a linear plasmid
How do you diagnose borrelia hervisii and borellia recurrentis?
Through blood smears
