Helicobacter pylori

Categorization
Cell Wall: Gram Negative Shape: Curved Rod
Metabolism: Facultative Anaerobe
Transmission
  • H. pylori is a frequent member of the GI flora in many individuals and only infects humans. The precise route of transmission is not known but infection rates are higher in areas of poor sanitation and crowding.
Virulence Factors
  • Urease: H. pylori urease allows generation of ammonium which increases the local pH and protects the bacteria from stomach acid.
Clinical Consequences
  • Chronic Gastritis and Peptic Ulcer Disease
    • H. pylori largely exist in the mucous overlying the gastric epithelium and causes a Chronic Gastritis which in some individuals is accompanied by Peptic Ulcer Disease in the gastric mucosa. Both bacterial and host immune factors probably contribute to mucosal injury and consequent ulceration. H. pylori infection also induces enhanced stomach acid secretion which causes gastric metaplasia in the duodenum, allowing colonization of bacteria in the small intestine and thus duondenal ulcers.
  • Gastric Lymphoma
    • Gastric Lymphoma is one of the notable complications of long term infection with H. pylori. Lymphoma likely arises due to long-term inflammatory stimulation of local immune cells.
Treatment
  • Regimen 1: Clarithromycin, Amoxicillin
  • Regimen 2: Bismuth, Metronidazole, Tetracycline
  • A Proton Pump Inhibitor is also often given such as omeprazole