Spirochetes Flashcards
What are spirochetes?
Gram negative bacteria/atypically staining bacteria that are spiral
What three spirochetes do you need to commit to memory?
treponema pallidum, borrelia burgdorferi, and leptospira interrogans
Syphillus cannot be visualized on gram stain, how do we see it then?
immunoflurescent microscopy or darkfield microscopy
Describe the rash of secondary syphillus
mucocutaneous copper colored rasg that invludes the mouth, hands, and soles
When will antibodies be positive for syphillus?
secondary
What test is often used as the confirmatory ab test for syphillus?
FTA-ABS
Positive serology but no symptoms of syphillus is defined as what stage of syphillus?
latent syphillus
Loss of the dorsal colimn-medial lemniscus tract of the spinal cord resulting in the loss of proprioception and sensation in the distal extremities; seen in tertiary syphillus
tabes dorsalis
this condition is seen in tertiary syphillus and is caused by midbrain lesions. It permits pupil contraction when changing focus from distant to near but prevents the pupillary light reflex
Argyll-Robertson Pupil
In this stage of syphillus, serology may be negative but CSF antibodies may be positive
tertiary syph
Elements of congential syphillus
saddle nose, hutchinson teeth, mulberry molars
What is the mechanism behind the Jarisch-Herxheimer reaction?
As the syphillus spirochete dies, LPS endodoxin is released and induces a sever inflammatory reaction. This occurs within 24 hours of antibiotic administration
Within 24 hours of abx admin for syph, pt demonstrates fever, rigors, leukopenia, and a diffuse macular rash
Jarisch-Herxheimer reaction
What stage of syphillus is the Jarisch-Herxheimer reaction most likely?
disseminated infection during secondary syphillus
Reservoir for Borrelia burgdorferi
Ticks (e.g., Ixodes deer tick) or mammals (e.g., mouse)
How do we visualize Borrelia burgdorferi
Largest spirochete
Visible in light microscopy using: Wright or Giemsa stain (aniline dyes)
Photomicrograph of a blood smear (Giemsa stain; 1000x magnification)
Numerous Borrelia spirochetes (examples indicated by black arrowheads) can be seen.
How do we treat borrelia burgdorferi?
Doxycycline OR 3rd generation cephalosporins (e.g., ceftriaxone)
Amoxicillin OR cefuroxime in pregnant women and children
What reservoir spreadds borrelia recurrentis?
Lice
Weil’s disease
A severe form of leptospirosis characterized by multiorgan involvement (e.g., hemorrhagic diathesis, hepatic dysfunction, renal dysfunction).
