Introduction: It has been suggested that H. pylori could be transmitted through vomitus. H. pylori must be able to survive in gastric juice for this to be possible. We studied the ability of the organism to survive in gastric juice outside the human body and identified factors affecting this.
Methods: H. pylori positive subjects (CLO testTM) were enrolled from all patients for culture. One antral biopsy and gastric juice (6 ml) were collected from all patients for culture. Three ml of the juice was placed in a nutrient broth (brain-heart infusion) to increase the pH towards neutrality. The pH of both samples was measured (corning pH meter 240). All juice samples were kept at room temperature untill culture was attempted at 0-2 hours, 6 hours and 24 hours. both samples and biopsies were cultured on a selective media for H. pylori under microaerophilic conditions.
Results:25 patients were enrolled and H. pylori was successfully cultured from gastric biopsy in all cases. Culture from unbuffered gastric juice was successful in 15/25 cases (60%) within 2 hours of collection (mean pH 4.3 ± 2.5). Of these the organism was successfullly recultured after 6 hours in 11 cases (73%). This fell to only 2 cases (13%) after 24 hours. In gastric juice added to neutrient broth (mean pH 6 ±1.2), the organism was isolated in 16 out of 25 cases (64%) within 2 hours of collection. Of these the organism was successfully recultured after 6 hours in 14 cases (87.5%) and after 24 hours in only 2 cases (12.5%).
Conclusion: We have demonstrated that H. pylori can be cultured from gastric juice in approximately two third of cases. The organism can survive in gastric juice for up to 6 hours especially if neutrients are added and the ph is higher. this supports the hypothesis that H. pylori could be transmitted by vomitus.