Comparação das cepas de Helicobacter pylori na placa bacteriana dental e mucosa gástrica

Abstract

Helicobacter pylori infection is extremely frequent over the world, mainly in development countries, including Brazil. It’s associated to chronic gastritis, duodenal and gastric ulcer, and is considered as an important risk factor for gastric cancer and gastric MALT lymphoma. The transmission routes remain unclear, but oral-oral and fecal-oral routs seem to be the most probable ones. The value of the presence of the bacteria on the dental plaque also remains unclear, and it maybe a source for gastric infection. Aiming in identifying and correlating the H. pylori stains found in gastric mucosa and dental plaque of 99 adult dyspeptic patients submitted to upper digestive endoscopies at Hospital Universitário João de Barros Barreto, in 2005 were evaluated. Samples from dental plaque were collected by sterile sticks and urease test and polymerase (PCR) chain reaction were undertaken. During the endoscopic procedure 6 pieces were collected from antrun and investigated by urease test, histopathology and PCR, after obtaining informed consent. The results were analyzed using BioEstat 3.0 package. The bacteria was found in 96% of gastric samples and in 72% of dental plaque samples, and this difference was statistically significant (p<0,001). There weren’t statistically significant differences related to age or gender. Every patient presented gastric diseases. In 18% of the cases lessons considered as of higher severity such as ulcers or pre-malignant lesions, as intestinal metaplasia, were found, and, among these, there were 82.4% of cases with both gastric and dental plaque infection. PCR was the most efficient test either on dental plaque and gastric mucosa samples. Among the 71 cases where the dental plaque samples were positive for the presence of the bacteria, the stains were identical to the gastric mucosa H pylori stains in 89%. The most common genotype was s1bm1cagA positive, either at dental plaque and gastric mucosa. The type 1 strains, considered the most pathogenic ones, were found in 63 patients on gastric mucosa and in 58 patients on dental plaque. The high frequency of H. pylori found on dental plaque might indicate the oral cavity as a colonizing locus for this bacteria and a risk factor for gastric infection.