Helicobacter pylori Flashcards
1
Q
What are acute and chronic diseases in the stomach?
A
- Acute: gastritis
- Chronic: chronic gastritis, peptic ulcer disease, gastric cancer
2
Q
Describe the physical features of H. pylori.
A
- Gram negative spirocete
- 4-6 polar. membrane sheathed flagella (membrane sheath protects flagellum protein components from harsh pH)
- oxidase, catalase and urease positive
3
Q
How doe H. pylori interact with oxygen (areobic, aneorobic…)?
A
microaerophilic (limited oxygen exposure)
4
Q
Where doe H. pylori typically infect?
A
human stomach causing chronic infection
5
Q
What are the 3 types of treatment for H. pylori infections?
A
- Omeprazole (proton pump inhibitor)
- Metronidazole
- Amoxicillin
6
Q
What are the virulence factors of H. pylori?
A
- Flagella
- Urease
- LPS
-Adhesins - VacA
- CagA
- genomic plasticity
- OMV (outer membrane vesicles)
7
Q
Flagella
A
- mobility combined with spiral shape allows for corkscrewing through mucin
- composed of 2 protein subunits (FlaA and FlaB)
- Enclosed in a membranous sheath which rotects the flagellum from proteases in stomach
8
Q
Urease
A
- protects bacteria until they reach mucin
- turns urea into CO2 and NH3 to buffer the pH
9
Q
LPS
A
molecular mimicry (uses sugars in human lewis antigen, avoids completation and can cause inflammation by cross reactivity to host cells
10
Q
Adhesins
A
enhances bacterial adheranc to the target cells
11
Q
VacA
A
- Vacuolating cytotoxin
12
Q
CagA
A
13
Q
Genome plasticity
A
repeat sequences that allow for gene duplication
14
Q
Outer membrane vesicles (OMVs)
A
- Containing alpha carbonic anhydrase (consumes protons) and buffers pH
15
Q
Adhesins of H. pylori
A
- bacteria in mucus layer has upregulation of MUC5AC that leads to increased production and increased adherance
