Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

Abstract

Introduction and aimsHelicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects. Materials and methodsIn a community survey, a diagnostic 13C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25 and 74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline (DOB) value, obtained in the 13C-urea breath test. ResultsA total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (p<0.0001) and the latter was significantly associated with the presence of symptoms (p<0.0001). ConclusionGastric urease activity was strongly associated with dyspeptic symptoms and cagA+H. pylori. Elevated 13C-DOB values could be used as indicators of a higher risk for gastric disease.