Spirochetes-Steinauer Flashcards
What is the structure of spirochetes?
- Long, slender, spiral.
- Axial filaments (flagella) attached in periplasmic space.
- Gram- (No LPS in treponema and borrelia.)
What are the basic characteristics of spirochetes?
- PCN is effective.
- Flexible cell wall similar to Gram-
- Motile
What two things can the genera Treponema cause?
Syphilis or skin infections
What causes syphilis? How is it transmitted? What is the pathogenesis? What are the virulence factors (2)?
Cause: Treponema pallidum.
Transmission: Person to person contact (sexual)
Pathogenesis: Invade the mucocutaneous tissue → lymphatics → systemic circulation → other tissues.
Virulence factors:
1. “Bare” outer membrane (few antigens) = sheath. 2. Hyaluronidase
Which stage of treponema pallidum is described as: 21 days for incubation. Develop a painless chancre. Heals w/n 3-6 weeks.
Primary Syphilis
Which stage of treponema pallidum is described as: resolves 3-6 weeks
•Macular rash (prominent lesions on soles and palms). Condylomata lata (lesions in moist areas).
•Systemic symptoms: fever, HA, malaise, sore throat, lymphadenopathy.
Secondary Syphilis
Which stage of treponema pallidum is described as: no signs or symptoms?
Latent Syphilis
Which stage of treponema pallidum is described as: 3 manifestations
•Gummas: granulomatous lesions of skin, bone and subcutaneous tissue.
•Neurosyphilis and CV syphilis.
Tertiary Syphilis
What is congenital syphilis?
transmission to fetus most likely during primary or secondary syphilis. Less likely during 1st trimester.
•Can have early symptoms or late (years later).
•Desquamation is common
How is Treponema Pallidum (Syphilis) diagnosed?
- Darkfield, immunofluorescence or silver stain.
•Best seen in primary or secondary stages. - Can’t be cultured.
- Serology:
•Nontreponemal: used during secondary syphilis (screening or monitoring test). Use regain (antibody) against cardiolipin (human protein). Test for agglutination. Looking for a non-treponema antibody that increases when infected.
•Treponemal: testing for antibodies against treponema. (confirmation test)
•Used during secondary stage.
What two species of Treponema cause skin infections?
- Yaws - Treponema pertenue
2. Pinta - Treponema carateum
What are the characteristics of Treponema skin infections (transmission, stages, manifestations)?
Transmission: Skin to skin contact.
Stages:
1. Primary: painless nodule that progesses locally.
2. Secondary: 6months-1 year later w/ widespread lesions.
3. Tertiary:
•Yaws: widespread bone joint and soft tissue destruction.
•Pinta: widespread pigmentary change.
What 3 diseases can Borrelia cause?
Relapsing fever, Lyme disease, Acute Necrotizing Gingivitis
What are the 2 species of Borrelia that cause relapsing fever? What transmits them? What is the reservoir? What is the pathogenesis? Symptoms? Diagnosis?
- Louse born: Borrelia recurrentis
o Human only reservoir.
o Africa and assoc. w/ overcrowding. - Tick born: Many borrelia spp. (soft ticks = Ornithodoros)
o Reservoir: small mammals.
o Assoc. w/ vacationing and outdoor activity (cabins).
Pathogenesis: Incubation → febrile → afrebrile → febrile → afrebile → etc.
Symptoms: fever, chills, HA, malaise, muscle pain, vomiting, and diarrhea.
Diagnosis: stain w/ wright stain or giemsa.
What species of Borrelia causes Lyme Disease? What is the vector? What is the pathogenesis? Diagnosis?
Borrelia burgdorferi.
Vector: black-legged tick (Ixodes) (hard-bodied)
Spirochetes penetration vessels and disseminate to other tissues
Pathogenesis: Get a bulls-eye rash (erythema chronicum migrans), flu-like symptoms → neurologic and cardiac symptoms → arthritis (in knees).
Diagnosis: based on serology (ELISA and IFA)
