No cultural detection of Helicobacter pylori in dental plaque

Helicobacter pylori causes human type B gastritis and is involved in the etiology of peptic ulcer disease. The routes of transmission of H. pylori are still unclear. The microorganism may be transmitted orally, since H. pylori has been detected in dental plaques. To confirm the hypothesis that dental plaques are a reservoir of H. pylori, 100 dental plaque specimens from 55 dental surgery patients were incubated on one nonselective and up to four selective agar media for the detection of H. pylori. In addition, urease activity of the plaque material was tested, and the gingival status of the patients was assessed. H. pylori was not cultivated from any of the specimens investigated. Plaque material from 12 patients with moderate and severe gingivitis showed urease activity. The results do not confirm the hypothesis that dental plaques are a relevant reservoir of viable H. pylori cells. However, non-cultivatable forms of H. pylori may survive in dental plaques. Urea cleaving activity of dental plaque may be a marker of gingival inflammation.