Increased Risk of Severe Gastric Symptoms by Virulence Factors , , , and in Infection.

Two virulence factors of , and , have been known to play a role in the development of severe gastric symptoms. However, they are not always associated with peptic ulcer or gastric cancer. To predict the disease outcome more accurately, it is necessary to understand the risk of severe symptoms linked to other virulence factors. Several other virulence factors of have also been reported to be associated with disease outcomes, although there are many controversial descriptions. isolates from Koreans may be useful in evaluating the relevance of other virulence factors to clinical symptoms of gastric diseases because the majority of Koreans are infected by toxigenic strains of bearing and . In this study, a total of 116 strains from Korean patients with chronic gastritis, peptic ulcers, and gastric cancers were genotyped. The presence of virulence factors , , , , and the extremely strong vacuolating toxin was found to contribute significantly to the development of severe gastric symptoms. The genotype combination // was the most predictable determinant for the development of severe symptoms, and the presence of was found to be the most critical factor. This study provides important information on the virulence factors that contribute to the development of severe gastric symptoms and will assist in predicting clinical disease outcomes due to infection.