Helicobacter, Vibrio, Campylobacter, Anaerobes Flashcards Preview

Gastrointestinal > Helicobacter, Vibrio, Campylobacter, Anaerobes > Flashcards

Flashcards in Helicobacter, Vibrio, Campylobacter, Anaerobes Deck (50):
1

What causes ulcers (Gastric and Duodenal for the most part)

Helicobacter Pylori

2

How is H. Pylori spread?

Fecal- Oral
Passage of Gastric Juices from human to human

3

H. Pylori is thought to cause what percentage of duodenal ulcers?

95%

4

H Pylori is thought to cause what percentage of gastric ulcers?

70%...the rest from NSAID use

5

Remember that H. Pylori can predispose to cancer because of the almost constant metaplasia

ok

6

Name the H. Pylori virulence factors

- VacA encodes "Vacuolating Cytotoxin"
- Cag
- Urease
- PAI (Pathogenicity associated Island)

7

What is VacA?

Vacuolating cytotoxin punches holes in endosomes and lysosomes which leads to cell death.

8

What is Urease?

Urease is secreted by H. Pylori because it neutralizes the acidic environment of the stomach

9

What is Cag?

rearranges the cytoskeleton

10

What is a Pathogenicity Associated Island?

A PAI is a big chunk of DNA that can be inserted into the bacterial chromosome. In the case of H. Pylori it encodes a type III secretion system which can bring in things from the outside

11

What is the morphology of H. Pylori?

Slender gram negative rods with flagella
Microaerophillic-- just want a little bit of air, almost anaerobic

12

What actually causes the ulcers in H. Pylori infection

Its a combination of the cell destruction from VacA, Cag, and immune response

13

Dx of H. Pylori

- Endoscopy with biopsy and culture
- Urea Breath test
- Serology

14

What's the most common bacterial infection in developed nations

Campylobacter jejuni

15

How would you come into contact with Campylobacter?

Undercooked poultry and unpasteurized milk, also contaminated water

16

morphology of campylobacter?

Seagull shape (spiral) gram negative rods
Like H. Pylori they are also microaerophillic

17

Incubation period of camp?

1 week

18

Clinical presentation of camp

- fever with apendicitis like pain.
- watery diarrhea that progresses to dysentery with blood and pus

19

Antecedent to Guillain Barre?

Remember that Guillain Barre is rising paralysis. Campylobacter is the most common antecedent to Guillian Barre. Thought to be related to lipooligosacharides from the camp mimicing myelin and the body developing an antibody to it.

20

How long does Camp usually last>

3-7 days

21

Vibrio looks like what?

Curved gram negative rods with a motile flagella
THEY ARE OXIDASE POSITIVE

22

Vibrio = oysters...commonly found in warm saltwater

ok

23

significant vibrio?

Vibrio cholerae
Vibrio parahaemolyticus
Vibrio Vulnificus

24

Cholera spread how

Contaminated water and food

25

Cholera serogroups are based on what

O antigen

26

How many serogroups of cholerae are there>

Over 200

27

Which serogroups are responsible for epidemic and pndemic cholera

O1 and O139

28

O1 serogroup divided into what two biotypes?

- El Tor
- Classical

29

20 liters a day

thats terrible

30

Incubation period of cholera

2-3 days

31

Remember, it takes a high infectious dose of cholerae to infect someone because the bacteria has a hard time making it through the stomach and into the lower bowel.

ok

32

rice water stool

cholerae

33

Virulence factors of cholerae?

- PAI encoded pillus
- Phage encoded toxin (AB Toxin) remember it activates adenylate cyclase and then cAMP which opens chloride channels

34

Cholerae diagnosis

stool culture on TCBS

35

Cholerae treatment?

oral hydration therapy + doxycycline or erythromycin

36

V. Parahaemolyticus

- Free-living in sea water
- Seafood associated food poisoning
- most common seafood illness in japan
- Gulf and Pacific coasts of US
- Watery diarrhea with cramps, nausea, vomitting

37

V. Vulnificus

Free living in sea water as well
- raw oysters or wound infection
- vomitting, diarrhea, abdominal cramps
- IC pts can become septic
- Rare but 20% fatal

38

What do anaerobes lack that prevents them from being able to survive in the presence of oxygen species?

Superoxide dismutase (SOD) and Catalase

39

How do anaerobic bacteria derive their energy?

From carbohydrate fermentation or breaqkdown of AAs

40

Most common anaerobic infection?

Bacterioides Fragilis

41

What is the morphology of Bacterioides Fragillis?

Gram negative Coccobacillus
Has an antiphagocytic capsule which means it can also infect the lungs

42

Prevotella Melaninogenica

Gram negative coccobacillus
Anti-phagocytic capsule

43

Gram Positive Spore forming rods?

Clostridium
These are the only anaerobic spore forming bacteria

44

Large Boxcar gram positive rods

Clostridium Perfringens

45

Gas Gangrene caused by

Clostridium Perfringens

46

How does Gas Gangrene come about

You get a contamination of a wound by the C Perfringens spores

47

Gas comes from?

carbo fermentation

48

C. Perfringens food poisoning

pretty common

49

Vibrio are oxidase?

Oxidase Positive

50

Vibrio Cholerae attach to small intestine epithelium via TCP

Toxin co-regulated pillus (TCP)