[Analysis of molecular fingerprint and virulence factors of Helicobacter pylori strains].

BACKGROUND: Helicobacter pylori is now accepted as the most important agent of gastritis in humans, as well as a risk factor for peptic ulcer disease and gastric carcinoma. The outcome of the infection is related to several factors, among them bacterial ones such as cagA and vacA s1m1 genotype. Random amplified polymorphic DNA (RAPD)-PCR, has been used to generate DNA fingerprints to evaluate similarity among strains within a bacterial species.

AIM: To assess the association between RAPD fingerprinting, virulence factors and the disease.

METHODS: H. pylori was isolated from 112 patients (41 with gastritis; 19 with gastric ulcers; 38 with duodenal ulcer disease; and 14 with gastroesophageal reflux disease). Allelic variants of cagA and vacA were identified using the polymerase chain reaction (PCR) and the fingerprints were generated by RAPD-PCR.

RESULTS: There was a strong association between the genotype vacA s1m1 and duodenal ulcers. Although RADP-PCR is a very useful tool in genotyping H. pylori, no significant correlation between the diseases studied and DNA fingerprint was detected neither with fingerprint and different vacA and, cagA genotypes.

CONCLUSIONS: The extension of our analysis to patients with well-characterized gastric diseases may provide significant information on the relationship between vacA genotypes and clinical outcomes of H. pylori infection.