Systemic spirochetes Flashcards
Describe how spirochetes appear microscopically. Do they gram stain? Do they grow in vitro?
Spirochetes are spiral-shaped organisms that exhibit corkscrew motility, don’t gram stain, and grow SLOWLY in in vitro or not at all.
What are the three geneses of pathogenic spirochetes?
- Treponema (pallidum and carateum) - all susceptible to penicillin, all have same serological responses in humans
- Borrelia - zoonotic infection
- Leptospira - zoonotic infection.
Can T. Pallidum be grown in culture?
NO
Can Borrelia be grown in culture?
yes - it is fastidious and microaerophilic
Can Leptospira be grown in culture?
Yes - aerobically in the right media
Borrelia burgdorferi - what disease does it cause?
Lyme disease: tick born
What is the tick that carries Lyme disease? The animals that are important to the life cycle of this tick?
Ixodes scapularis
Ixodes dammini
Reservoirs: white footed mice and white-tailed deer
Describe the clinical manifestations of lyme disease
Early infection (STAGE 1): localized infection - ERYTHEMA MIGRANS (bulls eye rash) at site of tick bite
Early infection (STAGE 2): dissemminated infection - secondary annular skin lesions, systemic symptoms such as severe malaise and fatigue. BELLS PALSY.
Late infection (STAGE 3): persistant infection: arthritis (like one knee), meningoencephalitis, neuropathies.
How do you diagnose Lyme Disease?
Clinically: have erythema migraines or a late manifestation
Laboratory: At least one of: isolation of B. burgdorferi, Diagnostic levels of IgM or IgG antibodies to spirochetes, or significant increase in antibody titer between acute and convalescent serum samples (4x rise in titer). Serologic: ELISA - only good to detect Lyme disease from here, not europe (different strain)
What is the therapy for Lyme Disease?
Oral antibiotics for stage 1: doxycycline
Stage 2: may need IV antibiotics
Is lyme disease forever?
No. It is probably reinfection.
What bug can cause a similar rash to Lyme Diseases’s erythema migraines bull’s eye?
Southern Tick-associated Rash Illness (STARI) - by lone star tick Amblyomma americanum
What causes relapsing fever? how do you define relapsing fever?
Borrelia sp - Recurrent episodes of fever separated by asymptomatic intervals
What is the difference in vector and reservoir of relapsing fever that is epidemic and endemic
Epidemic relapsing fever: human reservoir, body louse vector
Endemic relapsing fever: rodent/soft-shelled tick reservoir, soft-shelled tick vector
How is Borrelia recurrent transmitted?
From person to person by LICE. No animal reservoir, only occurs in epidemic form.