Helicobacter pylori: Bacterial Strategy for Incipient Stage and Persistent Colonization in Human Gastric Niches

Helicobacter pylori (H. pylori) undergoes decades long colonization of the gastric mucosa of half the population in the world to produce acute and chronic gastritis at the beginning of infection, progressing to more severe disorders, including peptic ulcer disease and gastric cancer. Prolonged carriage of H. pylori is the most crucial factor for the pathogenesis of gastric maladies. Bacterial persistence in the gastric mucosa depends on bacterial factors as well as host factors. Herein, the host and bacterial components responsible for the incipient stages of H. pylori infection are reviewed and discussed. Bacterial adhesion and adaptation is presented to explain the persistence of H. pylori colonization in the gastric mucosa, in which bacterial evasion of host defense systems and genomic diversity are included.

Presença de Helicobacter pylori na saliva de indivíduos com doenças gástricas superiores e doença periodontal / Presence of Helicobacter pylori in individuals with periodontal disease and upper gastric diseases

Helicobacter pylori (H. pylori) é um microorganismo Gram-negativo capaz de colonizar a mucosa gástrica e está associado a ulceras e câncer gástrico. Alguns estudos têm detectado esta bactéria na cavidade oral, sugerindo que esta funciona como um reservatório em potencial. O objetivo deste estudo foi analisar a prevalência do H. pylori na cavidade oral de indivíduos dispépticos sintomáticos (com queixa digestiva alta). Oitenta e nove pacientes com idade acima de 30 anos, com ou sem doença periodontal e com ou sem dispepsia gástrica, tiveram a saliva coletada e foram divididos em quatro grupos: Grupo A - Indivíduos com gastrite e doença periodontal; Grupo B - Indivíduos com gastrite e sem doença periodontal; Grupo C - Indivíduos sem gastrite e com doença periodontal; Grupo D - Indivíduos sem gastrite e sem doença periodontal.. As amostras foram analisadas através da PCR utilizando primers baseados no gene 16S rRNA, HPU1:5'- GCC-ATT-GGT-AAA-TTA-GTT-3' e HPU2:5'- CTC- CTT- AAT- TGT- TTT-TAC- 3' e visualizados por gel de agarose a 1% e luz ultravioleta. Os resultados demonstraram a presença do H. pylori em 22.2% (8/36) da saliva dos indivíduos do Grupo A; 18.7% (3/16) de indivíduos do Grupo B; e não foi detectado nos Grupos C e D. A diferença entre os Grupos A e B não foi estatisticamente significante (Fisher´s exact test, p< 0,05). No entanto quando analisados em conjunto, houve uma diferença significante na freqüência de H. pylori na saliva dos indivíduos com gastrite (A e B) quando comparados com os indivíduos sem gastrite (C e D). Os resultados deste estudo comprovam que o H. pylori está presente na cavidade oral de alguns indivíduos com gastrite e pode ser detectado na saliva.

Helicobacter pylori is a Gram-negative microorganism which is able to colonize the gastric mucosa and is associated with gastric ulcer and cancer. Several studies have detected this bacterium in the oral cavity, suggesting it as a potential reservoir. The aim of this study was to investigate the presence of Helicobacter pylori in the oral cavity of individuals with periodontal and gastric diseases. Eighty and nine individuals, with mean age 42.3 yrs, from a suburb of Rio de Janeiro participated in the study. They were divided in four groups: Group A - With gastric diseases and periodontal disease; Group B - With gastric diseases and no periodontal disease; Group C - Without gastric diseases and periodontal disease; Group D - Without gastric diseases and without periodontal disease. Saliva samples were collected from all volunteers and prepared for polymerase chain reaction (PCR) analysis using specific primers. Fisher´s exact test was used for detecting statistical differences between groups. Helicobacter pylori was detected in saliva of 22.2% (8/36) of Group A, 18.7% (3/16) of Group B, 0 ( 0%) of Groups C and D. There was'nt a statistically difference of Helicobacter pylori in Groups A and B. Helicobacter pylori can be detected in saliva of individuals with gastric diseases The organism seems to be able to colonize oral cavity at least temporarily. Key words: