Lecture 11: Spirochetes and Vibrios Flashcards
What are three methods of spirochete transmission?
sexual
vector-borne
environmental
Spirochetes cross quickly and easily into the _______, causing immediate _______ and eventual _______ infections.
bloodstream
bacteremia
multi-organ
Spirochete virulence factors are mainly for _______.
immune evasion
Spirochetes can _______ the host to decrease the host’s immune response.
immunomodulate
Why are there no vaccines for spirochetes?
No appropriate virulence factors to target - virulence factors are for immune evasion
Why is diagnosis of spirochete infection difficult? (3 reasons)
- infection proceeds in phases with months to years in between
- Treponema are too small to see by standard microscopy
- Lyme Disease has no quick and clear lab test
What exams can be useful in diagnosing spirochete infection?
Eye exam
Do spirochetes have acquired antibiotic resistance?
Little
What is the Jarisch-Herxheimer reaction to treatment?
very sick 24 hours after treatment
used to confirm spirochete infection (Lyme)
Which spirochete infection can be detected using eye exam?
neurosyphilis
What are the three stages of syphilis?
- Painless cancre
- Variable rash - flulike symptoms, possible meningitis
- EITHER latency OR dangerous cardiac and CNS involvement - gummas possible (noncancerous granuloma)
Congential syphilis is devastating but can be treated with ______
prenatal care
How long does Lyme take to transmit?
24 hours
What is the procedure for tick removal and Lyme prevention?
tweezers
possible doxycycline
What are the three phases of Lyme?
- Skin infection (usually rash)
- Immune/neurological issues
- Chronic Lyme
What is involve with Chronic Lyme?
Severe immune, neuromyalgia, fibromyalgia
How long should Lyme be treated with antibiotics?
no more than a month
What is the shape and Gram staining of vibrios?
curved rods
G-
Where do most vibrios live?
oceans
some are halophiles
What do vibrios primarily cause?
fecal-oral gastroenteritis
What species of vibrio causes stomach ulcers?
H. pilori
Gastroenteritis and peptic ulcers, caused by vibrios, require _____ virulence factors
GI
V. cholerae has a complex ______ lifestyle outside human host
planktonic (water)
Mmost pathogenic strains of V. cholerae, a 1_____, bear 2______ of colonization by 3_______ that carries 4_________.
- vibrio
- O1 genetic marker
- lysogenic bacteriophage
- virulence factors
How is V. cholerae usually transmitted?
fecal-oral route
If V. cholerae is not killed by stomach acid, what does it do?
secretes mucinase to attach to and to colonize the intestine
After V. cholerae colonizes the intestine, an 1_______ which interferes with 2_________ causes 3_______
1 A-B subunit enterotoxin
2 signal transduction
3 massive watery diarrhea
What are the two main problems with V. cholerae?
dehydration
electrolyte imbalance
Are antibiotics necessary to treat cholera?
not always - infection is self-limited