Flashcards in Helicobacter Deck (44):
Helicobacter disease is gram _____
Helicobacter is ____ shape
Helicobacter disease is found where?
found in the stomach
Helicobacter disease is what type of bacterium?
gram negative miicro-aerophilic bacterium
How many people are infected by Helicobacter?
significant portion (possibly 50%) of population is infected
Helicobacteria is present in patients with what?
-chronic gastritis and
What are the symptoms of Helicobacter disease?
-sometimes black stool
Helicobacter can be possible causes of what?
-gastric cancer (carcinoma)
Helicobacter pylori is originally classified as ____
Helicobacter pylori infects how much of the population?
significant portion (possibly 50%) of the population infected
How do the flagella of H. pylori help adhesion?
the flagella help burrow in the mucus layer and to reach epithelial layer.
What does BabA stand for?
blood-group antigen binding adhesion
What does SabA stand for?
Sialic acid binding adhesion
What do the antigens SabA and BabA in H. pylori do?
they trigger inflammation and help Helicobacter with adhesion
What does urease from H. pylori help colonization?
It produces ammonia and buffers acid pH; triggers apoptosis (death of cells)
H. pylor can modifiy what? how is this a virulence factor?
by modifying its peptidoglycan which helps immune evasion
How does H. pylori's LPS play a role in virulence?
It binds to toll like receptors which can activate B cells and reduce pathology.
What are people with TLR (toll like receptor) at higher risk for when infected with H, pylori as well?
more prone to tissue damage and cancer
What toxin of H. pylori that causes tissue damage?
CagA (cytoxin associated gene A)
What type of secretion in H. pylori is involved in injecting CagA into gastric cells?
cagA is a virulence of H. pylori located where?
on a pathogenicity island
CagA is a virulence of H. pylori that is associated with what?
What does cagA do with several host genes?
What is Tip-alpha
Tumor Necrosis factor alpha inducing protein; virulence of H. pylori
What is Tip-alpha associated with?
carcinogensis; hy. pylori virulence
Vaculoating cytotoxin A (vacA) is a virulence factor if H. pylori that causes what?
vacuole formation (large vesicles in host cells)
VacA targets what?
VacA can induce what
what is apotosis?
the death of cells
The vac A virulence is a major contributor to what? Why?
Gastric cancer; because of the increased occurences of mutation due to direct damage of DNA (free radicals primarliy ROS, NOS) and a deficient repair of mutations
How is H. pylori diagnosed
-based on symptoms of chronic gastritis, GERD (gastroesophageal reflex disease)
-13C urea breath teast (urease test)
-antigen in stool
-Endoscopy, tissue staining with immunostain
How is H. pylori r treated?
triple/ quadruple therapy
What is triple/quadruple therapy in regards to H. pylori ?
Treatment in which Mentronidazole + tetracycline + Bismuth sulphate is used and sometimes also a proton pump inhibito (omeprazole) to allow healing
what are toll like recpetors?
a class of proteins that play a key role in innate immune system
H. pylori adhesin has what type of binding?
apical binding; apical colonization and signaling to known and unknown receptors on gastric epithelium
H. pylori directs what?
Upregulation of H. pylori transcription factors such as _____ leads to production of what?
upregulation of transcription factors such as NF-kB leads to the production of pro-inflammatory cytokines and chemokines
Secretion of mediators at the basolateral surfaces does what?
attracts immune cells to the site of infection
Upon host cell contact, H. pylori assembles what? Resulting in what?
T4SS (type 4 secretion) pili at the surface enabling (allowing) delivery of molecules from bacterial cytoplasm into host cells
What molecules at the surface of host cells are enabled into the host via T4SS?
Cag A and peptidoglycan
cag PAI proteins include
Cag PAI proteins interact with _____
Interactions with phosphatidyserine (PS) and cholesterol in lipid rafts are inolved in ____ processing