Clinical Bacteriology: Spirochetes and Zoonotic Intro Flashcards
What are the major three pathogenic spirochetes?
Which one can be visualized by stain?
B**orrelia, **L**eptospira, and T**reponema (BLT)
B**orrelia can be visualized using aniline dyes (Wright or Giemsa stain) in light microscopy. (B** is Big)
_T_reponema is visualized by dark-field microscopy.
What kind of disease does Leptospira interrogans cause?
What is an especially severe form called?
Where is it found and prevalent?
Flu-like symptoms, jaundice, photophobia with conjunctival suffusion (erythema without exudate).
Weil disease: Severe form with jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage, anemia.
Found in water contaminated with animal urine, prevalent among surfers in the tropics.
What is the organism that causes Lyme disease?
What is its vector, and what organism does it share it with?
Lyme disease is caused by Borrelia burgdorferi
Transmitted by the Ixodes tick (also vector for Babesia).
Reservoir is the mouse.
What are the symptoms of Lyme disease?
How do you treat?
Initial symptoms: Erythema chronicum migrans rash, flu-like symptoms, with or without facial palsy.
Later symptoms: Monoarthritis (large joints) and migratory polyarthritis, cardiac (AV nodal block), neurologic (encephalopathy, facial nerve palsy, polyneuropathy)
FAKE a key Lyme pie:
Facial nerve palsy (typically bilateral), Arthritis, Kardiac block, Erythema migrans
Give doxycycline or ceftriaxone.
What is the cause of syphilis?
What is the treatment?
Caused by spirochete Treponema pallidum
Treatment is Penicillin G
What are the symptoms of primary syphilis?
How would you test for it?
Painless chancre.
Use dark-field microscopy to visualize treponemes in fluid from chancre
Serologic tests: VDRL/RPR (non-specific test), confirm with specific test FTA-ABS
What are symptoms of secondary syphilis.
How is it tested for?
Disseminated disease with constitutional symptoms, macropapular wash that INCLUDES PALMS AND SOLES (unusual!), condylomata lata.
Dark-field microscopy fluid from condylomata lata lesions, VDRL/RPR (nonspecific), confirm withFTA-ABS (more specific).
Secondary syphilis = Systemic. Latent syphilis follows.
What are some symptoms of tertiary syphilis? Signs of disease?
How do you test for neurosyphilis?
Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, “general paresis”), Argyll Robertson pupil (light-near dissociation - unreactive to light, constrict to focus on near objects)
Signs: Broad-based ataxis, positive Romburg test (sensory neuropathy), Charcot joint (rapid destruction of a weight-bearing joint), stroke without hypertension.
Test spinal fluid for VDRL or RPR.
What are signs of congenital syphilis?
How to prevent?
Saber shins, saddle nose, CV VIII deafness, Hutchinson teeth, mulberry molars.
Treat mother early in pregnancy, placental transfer typically occurs after first trimester.
What does VDRL test?
What are diseases that show false positives?
Detects nonspecific antibody that reacts with beef cardiolipin.
Inexpensive and quantitative.
VDRL:
Viruses (mono, hepatitis)
Drugs
Rheumatic fever
Lupus and leprosy
You begin treatment for a patient’s syphilis with penicillin and he begins to develop a flu-like syndrome.
What happened?
Jarisch-Herxheimer reaction - due to killed bacteria releasing pyrogen.
Classically associated with syphilis, can also occur with other spirochetes.
What disease is caused by anaplasma species?
What is its transmission and source?
Anaplasmosis
Ixodes ticks (live on deer and mice)
What disease is caused by Bartonella species?
What is its transmission and source?
Cat scratch disease, bacillary angiomatosis
Cat scratch
What disease is caused by Borrelia burgdorferi?
What is its transmission and source?
Lyme disease
Ixodes ticks (live on deer and mice)
What disease is caused by Borrelia recurrentis?
What is its transmission and source?
Relapsing fever
Louse (recurrent due to variable surface antigens)
