Detection of Helicobacter pylori in oral yeasts from students of a Chilean university.

Introduction: Nearly 73% of the Chilean population is infected with Helicobacter pylori (H. pylori), a factor predisposing for gastric cancer. Recent studies have demonstrated the presence of this pathogen within yeasts, suggesting that this fact can directly influence the failure of a treatment, transmission, and reinfection.

Aim: To detect the presence of H. pylori inside oral yeasts isolated from students of the University of Concepción (Chile).

Methods: 72 samples, obtained from the oral cavity using cotton swabs were incubated in YPD broth for 48h at 37°C and posteriorly seeded in Sabouraud Dextrose agar plus chloramphenicol at the same temperature and for the same time. Yeasts isolated were observed microscopically (wet mounting and Gram-stained) and identified using microbiological techniques. Intracellular H. pylori detection was performed by the amplification of 16S rDNA by PCR.

Results: Oral yeasts were detected in 24 samples (33.3%), being C. albicans (79.2%) the most frequent species, followed by C. dubliniensis (12.4%), C. krusei (4.2%), and C. tropicalis (4.2%). When analyzed by PCR, 15 of the 24 oral yeasts 62.5 % were positive for H. pylori 16S rDNA. From the 15 individuals positive for yeast harboring H. pylori, 81% of them reported stomach discomfort, and the presence of the bacteria was diagnosed at some moment in 20% of them.

Conclusion: The intracellular presence of the H. pylori in oral yeasts suggests an endosymbiotic relationship of these microorganisms, which could favor H. pylori transmission and reinfection in the gastrointestinal tract.