Lecture 11 - Rickettsia, Chlamydia & Mycoplasma Flashcards
How is Rickettsia spread?
Arthropod-spread, Humans are ‘accidental hosts’
What circumstances do Rickettsia need to survive?
They are obligate intracellular parasites
T or F, Rickettsia are small, stain poorly with gram stain and are gram negative coccobacilli
True
Why are Rickettsia obligate intracellular parasites?
They lack many of the enzymes required to produce amino acids and thus depend on host derived AA.
How is the bacteria spread and its mode of infection?
Infected tick, mite, louse or flea defecates as it eats its blood meal
Person itches the site which brings feces and bacteria in contact with wound
Bacteria enter blood stream and infects endothelial cells
Replicate slowly, affect adjacent endothelial cells, kil them and cause local blockage of blood flow (Rash)
What are symptoms of Rickettsia infection?
Fever, chills, rash and headache
What may occur in severe cases of Rickettsia infection?
Can cause vascular damage in multiple organs and tissues
Most of the symptoms of Rickettsia are due to what?
LPS flooding blood stream
What is the most common and important disease of Rickettsia
Typhus
Name the three different Typhus diseases
- Epidemic Typhus
- Endemic Typhus
- Scrub Typhus
What vectors are associated with each of the three typhus diseases?
Epidemic Typhus - Louse
Endemic Typhus - Flea
Scrub Typhus - Mite
Which of the three typhus diseases is unique and have humans as the reservoir?
Epidemic Typhus. We are reservoir or our clothes are.
R. prowazekii is associated with what disease?
Epidemic typhus
Which of these do Rickettsia have? LPS, Cell Wall
Both
What is the treatment for Epidemic Typhus
Sanitation and antibiotics