Helicobacter pylori

Question 1

What are the general characteristics of H. pylori

Answer 1

Gram -
Helical-shape
Miroaerophilic
Motile

Question 2

When was H. pylori identified and by who?

Answer 2

1983

By Australian scientists:

Barry Marshall
Robin Warren

2005 Nobel prize

Question 3

H. pylori was formerly known as:

Answer 3

Campylobacter pylori

Question 4

H. pylori has infected ___% of the world population.

Answer 4

50%

Perhaps the most common bacterial infection in the world

Question 5

Where in the body is H pylori found?

Answer 5

Human stomach

Question 6

What does H pylori cause?

Answer 6

Gastric ulcers and cancer (class 1 carcinogen)

Question 7

Specific characteristics of H pylori:

Answer 7

Cel dimension: 0.5x3 mm

6-8 polar flagella

Small genome (1.6 Mbp)

Question 8

When did scientists become interested in H pylori?

Answer 8

After it was discovered that it could cause cancer
~ 1990-2009

Found in 1983*

Question 9

Most people that are colonized with H pylori have ______.

Answer 9

Asymptomatic, chronic gastritis

Question 10

What percent of people develop gastric or duodenal ulcers from H pylori?

Answer 10

~10%

Question 11

What percent of people develop cancer from H pylori?

Answer 11

1%

Gastric cancer
More rarely: gastric MALT lymphoma

Question 12

____ ____ is a well-established risk factor for adenocarcinoma.

Answer 12

Atrophic gastritis

Question 13

What is an ulcer?

Answer 13

A hole in the epithelial cells

Question 14

What are the symptoms of gastric ulcers?

Answer 14

Epigastric pain(on empty stomach)

Nausea

Anorexia

Vomit

Bleeding

Burping

Question 15

How many new cases of gastric ulcers occur annually?

Answer 15

1/2 million

500,000 - 850,000

Question 16

How many Americans suffer from gastric ulcers at some point in their life?

Answer 16

25 million Americans

Question 17

What are the outcomes following H pylori infection?

Answer 17

Normal gastric mucosa —> weeks: superficial gastritis —> years: chronic gastritis !—>! atrophic gastritis OR assymptomatic state OR gastric duodenal ulceration OR MALT Lymphoma —> intestinal metaplasia —> Dysplasia —> Gastric ADENOCARCINOMA

Question 18

Lowest % of H pylori infection in _____

Answer 18

Australia.. where it was discovered.

Question 19

How is H pylori transmitted from person-person?

Answer 19

Oral-oral: kissing

Fecal-oral: poor hygiene (reason why developed world has lower rates)

Question 20

H pylori virulence factors:

Answer 20

Urease

Adhesins (BabA, SabA)

CagA secreted by T4SS

VacA vacuolating cytotoxin

Question 21

How does H pylori survive in the stomach?

Answer 21

It metabolizes urea to ammonia to raise the pH in the stomach

Question 22

Why is the flagella of H pylori important?

Answer 22

H pylori needs to move in order to colonize

Question 23

Which is thought to be the cancer causing virulence factor of H pylori?

Answer 23

CagA

Question 24

VacA virulence factor causes:

Answer 24

Immune modulation 
Vacuolating
Damage
Apoptosis
Permeability

Question 25

CagA is secreted by:

Answer 25

T4SS

Question 26

BabA and SabA help H pylori to:

Answer 26

Adhere to the gastric epithelial cells. They are adhesins

Question 27

Invasive tests to diagnose H. pylori:

Answer 27

Biopsy: mucosal gastric biopsy for

Urease test
Histology
Culture

Question 28

Non-invasive test for H. pylori :

Answer 28

Serological test
Urea breath test
Stool antigen test

Question 29

How is H pylori treated?

Answer 29

Cocktail of 3-4 antibiotics daily with follow up therapy

Question 30

Theory of H pylori development as human disease

Answer 30

Thought to be in the stomach of goats that maybe became zoonotic after domestication