C3 Helicobacter pylori Flashcards
More normal microbiota present in tongue/mouth, or in oesphagus/stomach?
Tongue and saliva has millions of bacteria per mL
Two types of bacteria in the stomach
Nausea, diarrhea and vomitting bacteria
-short term survival but unable to colonise
Gastric ulceration
- H.pylori
- long term survival and able to colonise
When does H pylori infection occur?
Infection very common in childhood
Symptoms usually not present until adulthood
Many asymptomatic infections not well understood
What are the requirements of a bacteria that alllows H pylori to survive and colonise in stomach?
What does this result in?
Acid neutralising system - urease enzyme and transporter proteins Adhesion molecules -bind to sugar molecules (blood group antigens) on surface of stomach Movement -flagella Degradation of mucus -enzymes; lipases and proteases
Consequently; the mucus layer is damaged and epithelial cells are no longer protected against gastric acid
Function of the urease enzyme
Catalyses urea conversion to carbon dioxide and NH3
Non-invasive test for H.pylori
Breath
Blood
Stool
Invasive test for H.pylori
Gastroscopy/biopsy fir culture
+ sensitivity tests also carrid our
What does the urea breath test tell us
Based on detection of what?
- detection based on urease enzyme activity (H.pylori defense mechanism allowing its colonisation)
- based on detection of heavy C13 carbon label
Journey of heavy carbon isotope
carbon in urease enzyme expulsion as CO2 as by product of NH3 +CO2 equation
What is a monoclonal antibody?
Single antibody
Produced by cells
What are polyclonal antibodies?
Mixture of antibodies isolated from serum
Why are two antibiotics used in eradication therapy of H.pylori?
H.pylori displays poor sensitivity to any single antibiotic
Combination is more potent than single use +synergistic action
