[Genetic diagnosis of H. pylori strains].
Helicobacter pylori strains are divided into two broad families, type I and type II, based on whether or not they possess the cag pathogenicity island (cagPAI). It has been suggested that cagPAI is inherited by horizontal transfer from an unknown microorganism, and the genes of cag are thought to be encoded by a putative type IV secretory system. In addition, CagA may be delivered from attached H. pylori into the host crytoplasm by this system and is tyrosine phosphorylated in gastric epithelial cells. The phosphorylated CagA may play a crucial role in promoting the inflammatory responses of gastric mucosa. These findings suggest that type I H. pylori is a pathogenic H. pylori.
Azuma
T
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Second Department of Internal Medicine, Fukui Medical University.
D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics; D005753:Gastric Mucosa / Q000382:microbiology; D005757:Gastritis, Atrophic / Q000175:diagnosis / Q000382:microbiology; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori