[Polymorphism of Helicobacter pylori urease genes and gastric diseases].

Helicobacter pylori (HP) is now recognized as a major etiologic agent of chronic gastritis and peptic ulcer and is recently presumed to be a cofactor in the occurrence of gastric cancer. HP has a high urease activity, which possibly plays a role in the pathogenesis of gastroduodenal diseases. In this paper, the function and the genetic structure of HP urease gene and the restriction fragment length polymorphism (RFLP) among HP strains using a probe of HP urease alpha subunit gene were described. HP urease gene cluster, which included structure genes, regulatory genes and accessory genes was identified and associated with the activity and the assembly. The RFLP pattern of HP tends to be distinct in gastric diseases, 460 bp pattern in gastric ulcer and 1,100 bp pattern in chronic gastritis, by Hae III digestion. HP showing a 460 bp RFLP pattern possessed a relatively high urease activity.