Flashcards in Travel Associated Illnesses Deck (79)
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1
Describe the structure of Vibrios
Gram -
Comma Shaped
Polar Flagellum
2
How does the DNA of vibrios appear?
2 circular chromosomes
3
Vibrio pH happy place?
Highly alkali tolerent, but acid sensitive
4
How do vibrio feel about salinity?
Halotolerant, some halophilic
5
How are Vibrio cholerae classified?
Capsule, Biotypes, Serotypes
6
Disease state Vibrio cholerae has what capsule type?
O1 (no capsule)
7
Disease state Vibrio cholerae has what biotypes?
Classical
El Tor
8
What serotypes are associated with both biotypes? With One?
Both -- Ogawa, Inaba
Only El Tor -- O139
9
What medication is prone to promote Vibrio cholerae growth?
Antacid
Normally 10^6 needed, with AA only 10^3
10
Vibrio cholerae presents in what part of the body?
Small Intestine
11
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
12
Describe the "Rice Water Stools" seen in Vibrio cholerae infection.
Contains lots of mucus
10^8 vibrios/mL
No Blood
13
How does Vibrio cholerae tend to become a fatal disease?
Dehydration and Electrolyte loss
14
Vibrio cholerae is distributed where?
Around the world in water supplies via copepods
15
Hosts of Vibrio cholerae?
Only humans
16
What do we know about chronic Vibrio cholerae?
Very rare
"Cholera Delores"
17
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
18
How does ADP-ribosylating a Gs protein influence host function?
Activates adenylyl cyclase
Increased cAMP causes ion secretion into gut
Water follows ions
19
Relationship between pertussis and cholera?
Similar mechanism
Per. blocks the inhibitor
Cholera locks in active state
20
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
21
Most important component of treatment for Vibrio cholerae?
Rehydration and Electrolyte Replacement
22
An Oral Rehydration Salts (ORS) formula contains...
NaCl (3.5g/L)
KCl (1.5g/L)
NaHCO3 (2.5g/L)
Glucose (20g/L)
23
What medicinal treatment might be used for Vibrio cholerae?
Doxycycline can limit shedding, but can't stop the diarrhea
24
Describe Vibrio cholerae vaccines.
not very effective -- about 6 months
Use heat-killed O1 Classical Strain
Few doses available, used in outbreaks
25
Clinical presentation of Vibrio parahemolyticus
- 12-24 hour incubation
- Nausea, vomiting, watery-bloody diarrhea, maybe gastroenteritis
26
Where can Vibrio parahemolyticus be found? How is it typically spread?
Worldwide in Oceans
Raw/Undercooked Seafood
27
Pathogenesis of Vibrio parahemolyticus?
Biofilms
Type 3 and 6 Secretion Systems
Hemolytic/Cytotoxic Enterotoxin
28
How is Vibrio parahemolyticus treated?
Rehydration and electrolyte replacement
Doxycycline if necessary
29
Typical origin of Vibrio vulnificus infection?
Infected would from handling contaminated seafood
Bacteremia from eating raw oysters
30
