Classification

• Curved/spiral gram negative bacterium
• Present in gastric mucus in crypts and on the surface of gastric acid and duodenal biopsies
• More prevalent in the antrum than in the body of the stomach
• Microaerophilic, flourishing best in low oxygen and high CO2 / H2 atmospheres

Disease associations

1. Gastric erosion and gastric ulcer
2. Duodenal erosion and ulceration
3. Chronic gastritis
4. Gastric lymphoma of mucosa-associated lymphoid tissue
5. Gastric adenocarcinoma

Diagnostic tests

1. Gastric biopsy
   • Culture
   • Histology with modified Giemsa statin for helicobacter-like organisms
   • Urease test on a biopsy specimen in agar gel with indicator system
   • Urease test on biopsy specimen using detector strip that incorporates the indicator system
2. Urease breath test
   • Radio-labelled ¹³C or ¹⁴C given by mouth and measuring the amount of radioactivity in the breath as a consequence of splitting of Urea
3. Serum test
   • For H.pylori antibodies