Flashcards in Travel Associated Illnesses Deck (79)
Describe the structure of Vibrios
How does the DNA of vibrios appear?
2 circular chromosomes
Vibrio pH happy place?
Highly alkali tolerent, but acid sensitive
How do vibrio feel about salinity?
Halotolerant, some halophilic
How are Vibrio cholerae classified?
Capsule, Biotypes, Serotypes
Disease state Vibrio cholerae has what capsule type?
O1 (no capsule)
Disease state Vibrio cholerae has what biotypes?
What serotypes are associated with both biotypes? With One?
Both -- Ogawa, Inaba
Only El Tor -- O139
What medication is prone to promote Vibrio cholerae growth?
Normally 10^6 needed, with AA only 10^3
Vibrio cholerae presents in what part of the body?
Clinical presentation of Vibrio cholerae infection?
1-4 day incubation
Nausea, Vomiting, 1-2 loose stools
Acute, Profuse diarrhea -- "Rice Water Stool"
No Pain, Fever
Describe the "Rice Water Stools" seen in Vibrio cholerae infection.
Contains lots of mucus
How does Vibrio cholerae tend to become a fatal disease?
Dehydration and Electrolyte loss
Vibrio cholerae is distributed where?
Around the world in water supplies via copepods
Hosts of Vibrio cholerae?
What do we know about chronic Vibrio cholerae?
Explain the pathogenesis of Vibrio cholerae.
Fibriae bind gut epithelium
AB5 Toxin expressed (Toxin/Pilus regulated by riboswitch)
B binds to receptor ganglioside G-m1 of epithelial cells
A-A's SS bond is reduced
A1 uses NAS to ADP-Ribosylate a Gs Protein
How does ADP-ribosylating a Gs protein influence host function?
Activates adenylyl cyclase
Increased cAMP causes ion secretion into gut
Water follows ions
Relationship between pertussis and cholera?
Per. blocks the inhibitor
Cholera locks in active state
Explain how the Vibrio cholerae riboswitch works
The switch weakly blocks the genes for toxin and pilus at low temperatures (ocean). When moved to higher temperatures (stomach), unstable base pairings fall apart, allowing transcription of the toxin and pilus
Most important component of treatment for Vibrio cholerae?
Rehydration and Electrolyte Replacement
An Oral Rehydration Salts (ORS) formula contains...
What medicinal treatment might be used for Vibrio cholerae?
Doxycycline can limit shedding, but can't stop the diarrhea
Describe Vibrio cholerae vaccines.
not very effective -- about 6 months
Use heat-killed O1 Classical Strain
Few doses available, used in outbreaks
Clinical presentation of Vibrio parahemolyticus
- 12-24 hour incubation
- Nausea, vomiting, watery-bloody diarrhea, maybe gastroenteritis
Where can Vibrio parahemolyticus be found? How is it typically spread?
Worldwide in Oceans
Pathogenesis of Vibrio parahemolyticus?
Type 3 and 6 Secretion Systems
How is Vibrio parahemolyticus treated?
Rehydration and electrolyte replacement
Doxycycline if necessary
Typical origin of Vibrio vulnificus infection?
Infected would from handling contaminated seafood
Bacteremia from eating raw oysters