Spirochetes are Vibrios Flashcards
what is quorum sensing? why is it important?
the ability of pathogenic bacteria to sense their population density; certain gene products are only made at high population density
What are some of the methods of transmission for spirochetes?
sexual, vector borne (ie ticks), environmental
Describe the characteristic of infection?
cross easily into bloodstream, causing immediate bacteremia and eventual multi-system infection
Why might the spirochetes cause CNS isssues and meningitis?
They cross the blood brain barrier
What category do spirochete virulence factors fit in?
immune evasion
Why are there no vaccines against spirochetes?
they are not very antigenic, and they can immunomodulate the host to further decrease the response
Why is diagnosis of spirochetes difficult?
disease proceeds in phases that may be separated by months and years
treponema is too small to see by standard microscopy
lyme disease has no quick and clear lab test
How can treponema be detected?
dark field microscopy
What is Argyll-Roberston pupil?
Diagnostic test for spirochete diseases,
one or both pupils fail to constrict in response to light
but it will constrict if focused on a near object
Describe treatment for spirochetes once diagnosis is made?
Simple, little acquired antibiotic resistance
What is the Jarisch-Herxheimer response? Why is it important?
endotoxins released from dead bacteria; warn patient!
Describe syphilis stages
Occurs in 3 stages: goes from
- painless chancre
- variable types of rash with flu-like symptoms (meningitis possible)
- either latency or dangerous cardiac or CNS involvement (gummas possible)
Describe congenital syphilis
devastating and preventable
symptoms: miscarriage/stillbirth/neonatal death 40-50% of cases
within first 2 years surviving infants develop sever secondary syphillis
What is Lyme disease?
Tick borne, very common in the Northeast in the summer
How can you prevent Lyme disease?
Takes 24hrs to transmit, prompt removal of ticks with gloves, tweezers, possible doxyclycline can prevent
How many phases does Lyme disease have? What are they?
3 phases:
- skin infection (rash common)
- immune/neurological issues
- chronic Lyme with more sever immune, neuro- fibromyalgia
How long does treatment for Lyme disease take?
antibiotic for Lyme may take a month, no more: Jarisch-Herxheimer reaction may help confirm the diagnosis
what are gummas?
granulomatous lesion with rubbery necrotic center, primarily in liver, bones, and testes.
What happens during cardiovascular syphillis?
greater than 10 years after infection; develop aneurysm of ascending aorta caused by chronic inflammation of vasa vasorum
What are vibrios?
Curved, gram (-) rods.
Where are vibrios most often found?
most are ocean dwelling, several are halophiles
What is their primary mode of transmission?
fecal-oral gastroenteritis, may also infect wounds contaminated by seawater or debris
What does H. pylori cause?
peptic ulcers
What is the life cycle of V. cholerae outside the human host?
complex planktonic
