[Isolation of Helicobacter pylori from dental plaque].

It has been suggested that oral dissemination might be the major transmission vehicle for Helicobacter pylori, and that dental plaque might act as its reservoir. The presence of H. pylori was investigated in 62 odontological male and female patients (average age: 35 years old). Samples were taken from supragingival plaque, placed in 0.3 ml of thioglycolate broth, cultured within 12 h in Mueller-Hinton agar with the addition of 5-7% of sheep blood and antibiotic supplement, and incubated at 37 degrees C in microaerophilia for 5-7 days. Typical colonies were identified by gram, urease, oxidase and catalase. H. pylori was detected in a 15 year-old patient suffering from gastric acidity (1.61% positivity index). The medium used facilitated recovery of the agent from a sample abundant in germs. H. pylori was not recovered from the same patient 12 months later, suggesting that there might have been a transitory passage by gastric reflux or that the bacterium was acquired from an exogenous source.