Gastrointestinal Infections Part I Flashcards Preview

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Flashcards in Gastrointestinal Infections Part I Deck (48):
1

What is gastroenteritis?

Irritated GI system

2

What is a symptom of diarrhea?

Small intestines not absorbing secreted fluid and electrolytes

3

What is dysentery?

Invasion of large intestine resulting in bloody and purulent stool

4

What causes diarrhea?

Increased secretion
Decreased absorption

5

What is food-associated infection?

Multiplication of the organism in the body

6

What is food poisoning?

Microbial toxins in contaminated food

7

What do enterotoxins do?

Stimulate intestinal secretion (diarrhea)

8

How does cholera work?

B subunit binds GM1
Endocytosis
A subunit crosses ER membrane
A subunit transfers ACP ribosyl group from NAD to stimulatory G protein
G protein activates adenylate cyclase
Adenylate cyclase activates PKA using cAMP
CFTR is phosphorylated by PKA secreting Cl-

9

How are E. coli strains differentiated by their antigens?

Somatic (O)
Flagellar (H)
Capsule (K)

10

Most common E, coli strain in the United States?

Enterohemorrhagic
O157:H7

11

What does ETEC produce?

Enterotoxins (causing watery diarrhea)

12

What codes for enterotoxins in ETEC?

Plasmid

13

What does ETEC mimic?

Cholera toxin

14

What does ETEC cause?

Purely secretory diarrhea (no bloody stool or inflammation)

15

What does ETEC stand for?

Enterotoxigenc E coli

16

What does EPEC stand for?

Enteropathogenic E coli

17

What does EPEC cause?

Diarrhea in infants and young children sometimes bloody

18

EHEC stands for:

Enterohemorrhagic

19

What does EHEC encode for?

Shiga-like cytotoxin

20

How does EHEC shiga-like cytotoxin work?

Cleaves adenine off rRNA halting protein synthesis

21

What can EHEC cause?

Local necrosis and inflammation (hemorrhagic colitis)
Kidney damage (hemolytic-uremic syndrome)

22

What medium can test for EHEC?

Sorbitol MacConkey: non-fermentation of sorbitol makes the strain stand out

23

EIEC invasive or non-invasive?

Invasive

24

What does EAEC do when attaching to cells?

Aggregates

25

What is unique about E. coli bacteria?

Cannot kill all E. coli with antibiotics

26

What part of the colon does shigella invade?

Descending and sigmoid colon

27

What does shigella cause?

Bloody stool
Intestinal necrosis

28

Campylobacter gram stain:

Gram-negative

29

What diarrhea does Campylobacter cause?

Watery stool

30

What is campylobacter associated with?

Guillain-Barrie syndrome due to cross-reactive antibodies (no antibiotics necessary)

31

Gram stain for Vibrio cholera:

Gram negative

32

What is the vibrio cholera flagellum arrangement?

Monotrichous

33

Cholera stool:

Watery cloudy stool with mucus blebs (rice soup)

34

Main treatment of cholera?

IV rehydration

35

Where does Yersinia enterocolitica infect?

Ileum causing necrosis and bloody stool

36

Where is Vibrio parahaemolyticus found in concentration?

Shellfish (filter feeders)

37

Best diagnosis for Helicobacter pylori?

Carbon isotope-labeled urea for breath test (C 13 or 14)

38

What does H. pylori do?

Creates ammonia

39

Reaction H. pylori does:

CH4NO2 -> CO2 + NH3

40

Why don't you use clindamycin against C. diff?

It is effective against all anaerobes except C. diff making it the predominate species

41

Antibiotics for C. diff?

Metronidazole
Vancomycin

42

How to tell if it's C. diff?

PCR for toxin B gene

43

How to treat C. diff?

Fecal microbiota transplantation

44

Where can you catch Clostridium perfringens?

Fecal bacteria that contaminate MEAT

45

Where do Bacillus cereus spores germinate?

Cooked rice

46

How do staphylococcal enterotoxins work?

Give you food poisoning through toxins that work on the CNS (cytokines)to induce vomiting

47

What does botulism do?

Blocks the release of acetylcholine in the neuromuscular junction leading to flaccid paralysis

48

Treatment for botulism?

Animal-derived antitoxin