Enteric Bacteria vibrios (3)

Question 1

Bacteriology of Vibrios

Answer 1

curved gram negative rod

Question 2

What agar is good for culturing vibrios?

Answer 2

bile salts agar - selective for salt tolerance

Question 3

What vibrio has a moderately effective vaccine available?

Answer 3

Cholera

Question 4

What are the reservoirs for cholera?

Answer 4

humans and ocean microbial communities

-indian ocean and gulf of mexico

Question 5

Cholera has two lifestyle forms, what are they and which one is a source of genetic diversity?

Answer 5

planktonic and pathogenic

plank tonic is source of diversity

Question 6

How is cholera transmitted?

Answer 6

fecal oral transmission

Question 7

Where does cholera colonize? How?

Answer 7

colonizes lumen epithelium of small bowel with mucinase and toxin-coregulated pillus - TCP

Question 8

Are alot of cholera bacteria needed to infect someone?

Answer 8

yes - high infectious dose

Question 9

How does cholera create the massive diarrhea it is notorious for? What is the name of this?

Answer 9

choleragen exotoxin
AB signal transduction: A causes persistent activation of adenylate cyclase–> loss of water and ions

“rice water stool”

Question 10

Who is particularly susceptible to a cholera infection?

Answer 10

people on antacids or with gastrectomy

-stomach acid usually kills bacteria

Question 11

How does the cholera bacteria acquire the choleragen gene?

Answer 11

lysogenic bacteriophage CTX

Question 12

What are markers for the presence of CTX?

Answer 12

O1 and O139

Question 13

What is the usual cause of death from cholera?

Answer 13

dehydration and electrolyte imbalance - Acidosis and loss of potassium

Question 14

How would you diagnose and treat dehydration?

Answer 14

skin tenting pinching
treat: IV lacted Ringer solution

NOT just saline- acidosis

Question 15

What antibiotic is available to help shorten the course of cholera? What other vibiro is it effective for?

Answer 15

doxycycline

-parahaemolyticus

Question 16

What are the non-cholera vibrio infections? what are they associated with?

Answer 16

parahaemolyticus, vulcanis

1. self limited gastroenteritis
2. rapid progression cellulitis

Question 17

What is a notorious career that is associated with non-cholera vibrio infection?

Answer 17

working with raw shellfish

Question 18

What is the reservoir for parahaemolyticus and vulcanis

Answer 18

ocean water

they are halophiles - live in high salt

Question 19

What are important co-morbid conditions associated with a poor prognosis for infeciton with parahaemolyticus and vulcanis?

Answer 19

liver or renal disease
immunodeficiency
iron overload

Question 20

What is the typical appearance of cellulitis caused by the non-cholera vibrios?

Answer 20

hemorrhagic bullae

Question 21

How do you treat the cellulitis caused by non-cholera vibrios?

Answer 21

RAPID and aggressive surgery

Question 22

Are systemic symptoms present in cholera infection

Answer 22

usually not, pediatrics it can be since their gut is so thin

Question 23

What is similar about infection with cholera and non-cholera vibirios?

Answer 23

• possibility of dehydration
• self limited course
• efficacy of doxycycline treatment
• site of infection

Question 24

What is not similar about infection with cholera and non-cholera vibrios?

Answer 24

likelihood of dehydration and need for antibiotic

Question 25

V vulnificus is similar to gas gangrene in that it produces what virulence factor?

Answer 25

protease exotoxins