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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

Symptoms of Vibrio vulnificus infection?

Infected wounds from handling
Within hours, cellulitis and necrosis
Eventual liver damage
50% Fatal