RELATIONSHIP BETWEEN GENOTYPES OF HELICOBACTER PYLORI vacA AND cagA AND GASTRIC DISEASES

Objective To investigate the relationship between vacA and cagA genotypes of Helicobacter pylori (Hp) and gastric diseases. MethodsThis study consisted of 105 patients with various gastric diseases including chronic superficial gastritis (CSG, 45 cases), chronic atrophic gastritis (CAG, 48), and gastric cancer (GC, 12). Three pieces of antrum mucosa were obtained from each patient. Rapid urease test, histological examination and polymerase chain reaction (PCR) were carried out in the specimen. DNA was extracted from the specimen, and six pairs of primers were used to detect the gene expression of vacA and cagA. ResultsFifty-seven patients showed positive results in rapid urease test and histological examination, in which, the positive rate of Hp infection was 54.2% (57/105). The positive expression rates of vacA s1/m2, s1/m1, s2/m1, s2/m2 were 53% (30/57), 18% (10/57), 8%(5/57) and 21% (12/57), respectively. The expression rate of cagA was 89% (51/57). There was no significant differences in the expression of vacA, cagA among CSG, CAG and GC groups (P0.05). ConclusionCagA and vacA s1/m2 were the dominant genotypes of Helicobacter pylori. There was no significant association between Helicobacter pylori genotypes vacA and cagA and special gastric diseases. The vacA and cagA genotypes cannot be used for predicting clinical outcomes caused by Helicobacter pylori infection.