Evaluation of the virulence markers of Helicobacter pylori in dental plaque of patients with gastritis: A preliminary study

Helicobacter pylori (H. pylori) is a gram-negative motile spiral-shaped bacterium that is strongly associated with gastroduodenal diseases. Recently, dental plaque has been implicated as a possible source of H. pylori infection. Two important virulence factors that are expressed by the alleles of vac A (vacuolating toxin) and cag A (cytotoxin-associated gene A) have been identified. The aim of this study was to determine whether or not virulence factor genes vac A and cag A are present in H. pylori retrieved from dental plaque in patients with gastritis. In this cross-sectional study, dental plaque specimens from 42 patients with gastritis, referring to the endoscopy section of a hospital, were subjected to polymerase chain reaction (PCR) assay to detect the presence of cag A and vac A genotypes of H. pylori. DNA from H. pylori was detected in 4 dental plaque samples. All these 4 samples were vac A-positive and 2 samples were positive for both vac A and cag A genotypes. The pathogenic strains isolated from the dental plaque in the present study suggest it is possible for more than one virulence factor of H. pylori to exist in some patients. However, further studies are required to confirm this finding.