Helicobacter Pylori

Question 1

Distinguishing features

Answer 1

Gram negative spiral gastric bacteria with flagella 
Oxidase-positive 
Urease-positive 
Microaerophilic 
Grows at37 C on campy or skirrow agar

Question 2

Reservoir

Answer 2

Humans

Question 3

Transmission

Answer 3

Fecal-oral

Oral-oral

Question 4

Pathogenesis

Answer 4

Motile
Urease positive: ammonium cloud neutralizes stomach acid, allowing survival in stomach acid during transit to border
Mucinase aids in penetration of mucous layer (rapid shift Down to neutral as it penetrates)
Invasive into stomach lining where pH is neutral
Inflammation is prominent
Two biotypes(I an II) type I produces vacuolating cytotoxin

Question 5

Disease

Answer 5

Chronic gastritis and duodenal ulcers
Associated with several forms of stomach cancer (gastric adnocarinoma,gastric mucosa-associated lymphoid tissue lymphoma (MSLT-oma), b-cell lymphomas)

H.pylori classed as type 1 carcinogen

Question 6

Diagnosis

Answer 6

Biopsy with culture; histology with giemsa or silver stain
Urea breath test
Serology