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[A single strand comformation polymorphism of vacuolating cytotoxin gene in H. pylori]
1Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, 100730.
Objective:
To use PCR/SSCP analysis of the vacuolating cytotoxin gene (vacA) of H. pylori for differentiation of various strains of H. pylori.
Methods:
PCR was performed using the primers amplifing vacA gene of the bacteria embeded in the gastric mucosa of 159 patients with various gastric duodenal diseases. The products of PCR were further processed for SSCP analysis and southern blot hybridization. In the meantime, vacA genes of three different SSCP-patterns from three patients with duodenal ulcers were sequenced.
Results:
The rate of detection of H. pylori with the method was 100%. vacA1 and vacA2, the two subtypes of vacA, were 76.5% (114/149) and 23.5%(35/149), respectively. Eight different SSCP-patterns were distributed in various gastroduodenal diseases, and that 80% of duodenal ulcers was predominated with B pattern. Sequencing of DNA indicated a diversity of vacA gene structure.
Conclusion:
PCR/SSCP can be used in the differentiation of different strains of H. pylori in epidemology, and in the follow up study after H. pylori eradication, especially in the differentiation between H. pylori recrudescence and reinfection.