H pylori Flashcards
80% of gastric cancers are related to
h. pylori infections
5% of cancers WW are related to
h. pylori infections
If something is going on w/ the patient’s stomach and they are not taking NSAIDs it is likely
h. pylori infections
h. pylori is a group ___ carcinogen
1
h. pylori infections may increase the risk for:
gastric/duodenal ulcers, PUD, chronic superficial gastritis, hypertrophic gastropathy (Ménétrier’s Disease), atrophic gastritis, recurrent hyperplastic polyps of the stomach
h. pylori infections are associated with increased risk for _____________, an extra- gastrointestinal effect
Atrial fibrillation
What genetic polymorphisms increase the likelihood of developing gastric cancer from h. pylori infections
IL-1b, IL-1bR, TNF-a, IL-10
h. pylori properties
GN curved rod, facultative intracellular, non-invasive, Oxidase (+), urease (+), catalase (+), extremely acid tolerant, Microaerophilic, motile via sheathed flagella
Urease
ESSENTIAL for survival! production in h. pylori, converts urea to ammonia + CO2, which neutralizes stomach acid
Why is urease necessary to h. pylori
h. pylori is acid resistant NOT acid stable
50% of h. pylori strains are + for
cagA and vacA cytotoxins; remaining 50% of h. pylori secretes 1 or the other, few are double -
cytotoxin cagA mechanism
effector protein that is injected into stem-like cells in the due to Type IV secretion system, causes rearrangement of cytoskeleton, alters cell signaling, and perturbs cell cycle. Increases expression of DNA editing enzyme, which leads to mutations in p53
cytotoxin vacA mechanism
Causes dysfunction autophagy, in chronic infection reduces cathepsin enzyme activities and hinders the fusion of autophagosomes with lysosomes, accelerating the replication of H. pylori
CagA-negative h. pylori strains will cause
only chronic gastritis and have only a small chance of developing peptic ulcer disease or gastric cancer.
cagA toxin is associated with the development of
cancer and other cellular changes, peptic ulcer disease
vacA toxin is required for the development of
REQUIRED for ulcer formation and gastritis
Cag A-negative h. pylori strains will cause
only chronic gastritis and have only a small chance of developing peptic ulcer disease or gastric cancer
Oxidase (+) strains causing diarrheal illnesses
Vibrio, Campylobacter, Helicobacter, Aeromonas
Weight Loss presenting WITH Fever=
Balantidium Coli
Weight Loss presenting WITHOUT Fever=
Hymenolepsis Nana
H. pylori LPS affects
production of acid and secretion of pepsinogen
Virulence Factors of H. pylori
urease, cagA, vacA, and LPS
Which h. pylori virulence factor is necessary for survival?
urease; organism is acid-resistant, not acid-stable, after 30-60min will be killed if it does not neutralize toxins
Enterohepatic Helicobacter species (All species other than pylori) may cause
extragastric diseases - colonization of the hepatobiliary tract causing chronic biliary disorders (diseases of pancreas, liver, gall bladder primarily)