vacA genotypes of Helicobacter pylori in the oral cavity and stomach of patients with chronic gastritis and gastric ulcer

Helicobacter pylori adheres to various components of the human saliva. Therefore, the objective of this research was to simultaneously detect H. pylori in saliva and in gastric biopsy, and to determine the agreement between the vacA genotypes in both saliva and gastric biopsy.A total of 162 patients with chronic gastritis and 34 with gastric ulcer were studied, and saliva and biopsy samples were collected from each patient. H. pylori DNA was detected by conventional PCR and nested PCR was used for vacA genotyping.In 24% of the patients (47/196) H. pylori DNA was found in saliva and in biopsy; 52.5% (103/196) were saliva(negative)/biopsy(positive) and 6.6% (13/196) were saliva(positive)/biopsy(negative). In either or both H. pylori vacAs1m1 or s1m2 genotypes were detected in saliva in 41.5% of the patients with chronic gastritis. Forty-seven percent had >1 genotype, and the s1m1/s1m2 combination was found in 36% of them. H. pylori vacAs1m1 and s1m2 were also found in the saliva and biopsy of patients with gastric ulcer. The genotypes found in saliva and biopsy of the same patient had 51.1% agreement. In 27.6% of the 47 patients saliva(positive)/biopsy(positive) two genotypes were found in saliva, and one or both in the stomach.The s1m1/s1m2 genotypes, alone or together, are found simultaneously in saliva and gastric biopsy of the same patient. These results suggest that H. pylori reaches the oral cavity by various ways, and that saliva can be the transmitting and re-infecting vector.