Helicobacter pylori
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Helicobacter pylori
- Characteristics
- Gram negative rod
- First test in algorithm, narrows scope of bacteria
- Curved/spiral-shaped
- Oxidase +
- All gram negative curved rods are oxidase positive
- Urease +
- Produces ammonia, creating alkaline environment
- Helps H pylori survive in acidic gastric mucosa
- Catalase +
- Has flagella (motile)
- Gram negative rod
- Pathogenesis
- Commonly colonizes antrum of the stomach
- Most often the prepyloric area (less acidic)
- Destroys somatostatin-producing delta cells in the antrum, contributing to increased acid production
- Increased acid production and local inflammatory reaction to bacteria causes ulcer formation
- Commonly colonizes antrum of the stomach
- Presentation
- Gastritis
- Early manifestation of H pylori infection
- Presents with dyspepsia, bloating, belching, and epigastric pain
- Over time, results in potential complications
- Atrophic chronic gastritis
- Gastric cancer (adenocarcinoma)
- Gastric lymphoma (MALTomas)
- Gastric or Duodenal ulcers
- Increased acid production causes destruction of mucus layer, compounded with local inflammatory reaction to bacteria
- H. pylori is the most common cause of peptic ulcers, especially in the duodenum
- Gastritis
- Diagnosis
- Urea breath test
- Fecal antigen test
- Endoscopy with gastric biopsy
- H. pylori may be seen under the microscope
- Urease may be detected from biopsy of gastric mucosa
- Treatment
- Triple therapy
- Amoxicillin
- metronidazole is used if allergic to penicillins
- Clarithromycin
- Proton pump inhibitor (omeprazole)
- Amoxicillin
- Bismuth-based quadruple therapy if concerned about macrolide resistance
- Bismuth subcitrate, PPI, metronidazole, tetracycline
- Triple therapy