Spirochetes Flashcards
What are the general characteristics of spirochetes?
Thin and flexible organisms with one or more complete helical turns, a flexible cell wall, and endoflagella for motility.
Which species of Treponema are known to cause human disease?
- T. pallidum ssp. pallidum (syphilis)
- T. pallidum ssp. pertenue (yaws)
- T. pallidum ssp. carateum (pinta)
- T. pallidum ssp. endemicum (endemic syphilis or bejel)
What microscopy technique is best for visualizing Treponema species?
Darkfield microscopy.
True or False: The chancre in syphilis is highly infectious.
True.
What is congenital syphilis?
A multi-organ disease transmitted transplacentally that is severe and mutilating.
What is the drug of choice for treating syphilis?
Penicillin.
What microscopy technique can be used for diagnosing Borrelia infections?
Staining a blood smear with Wrights or Giemsa stain.
True or False: Leptospira interrogans can be found in drinking water.
True.
What is the primary animal reservoir for leptospires?
Dogs, rats, and other rodents.
What are the two stages of leptospirosis?
- High fever, headache, and muscle ache
- Meningitis, rash, and jaundice
What type of microscopy can be used to observe Leptospira?
Darkfield microscopy, phase contrast microscopy, and immunofluorescence.
How do leptospires live in their animal reservoirs?
Leptospires live in the renal tubules and are secreted in the urine.
Who is most commonly affected by leptospirosis?
Occupational exposure is common among veterinarians, dairy workers, swineherds, slaughterhouse workers, miners, sewer workers, and fish and poultry processors.
How is leptospirosis transmitted to humans?
Via direct contact with contaminated urine or indirectly through contaminated water.
How do leptospires enter the human body?
Through breaks in the skin or mucous membranes.
What is Weil’s disease?
A severe systemic disease that includes renal failure, hepatic failure, and intravascular disease, which can be fatal.
Is direct detection of leptospires in clinical specimens recommended?
No, it is not recommended.
What is the optimized method for detecting motile leptospires?
Centrifuging samples at 1500g for 30 minutes.
When can leptospires be cultured from patients?
From CSF or blood during the first week of illness, or from urine after the first week.
What is the incubation time for cultures of leptospires?
6-8 weeks in the dark at room temperature or 30°C.
What is the preferred method for detecting IgM antibodies in leptospirosis?
Indirect hemagglutination and ELISA test.
What is the effectiveness of penicillin in treating leptospirosis?
Effective if administered before the fourth day of illness.
What is the role of doxycycline in the treatment of leptospirosis?
Shortens the course of illness in adults and reduces the incidence of convalescent leptospiruria.
