Helicobacter pylori

• Organism: Helicobacter pylori (Formerly known as Campylobacter pylori)
• Organism type: Bacteria
• Discovered by: Warren & Marshall (1983)
• Host: Human
• Ecological niche (in human): Stomach (gastric epithelium/Mucous layer)
• Unique feature: Survival in the harsh acidic conditions (pH < 2) of the stomach
• Infection rate: 
  • ≈ 50% human population (globally) 
  • Incident rates vary in different regions of the world
• Pathogenicity: Pathogenic
• Diseases (In human host): 
  • Asymptomatic (most of the infected population)
  • Chronic gastritis
  • Peptic ulcers
  • Gastric cancer (adenocarcinoma)
  • Mucosa-associated lymphoid tissue (MALT) lymphoma
• Transmission mode: 
  • Exact mode of transmission is not known (Predicted)
  • fecal-oral or oral-oral route 
  • Poor hygiene and crowded conditions

FEATURES

• Gram staining: Gram-negative
• Shape: Spiral-shaped
• Size: ≈ 3 µm long
• Culture environment:Microaerophilic

• ≈ 50% of the world’s population is infected with Helicobacter pylori. Only a minority of the infected population can develop diseases such as chronic gastritis, peptic ulcers, gastric cancer (adenocarcinoma), and mucosa-associated lymphoid tissue (MALT) lymphoma
• It usually colonizes the human gastric (stomach) epithelium luminal surface