Outer Membrane Vesicles of Helicobacter pylori TK1402 are Involved in Biofilm Formation

Background: Helicobacter pylori forms biofilms on glass surfaces at the air-liquid interface in in vitro batch cultures; however, biofilms of H. pylori have not been well characterized. In the present study, we analyzed the ability of H. pylori strains to form biofilms and characterized the underlying mechanisms of H. pylori biofilm formation. Results: Strain TK1402 showed strong biofilm forming ability relative to the other strains in Brucella broth supplemented with 7% FCS. The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms. In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms. Biofilm formation was strongly correlated with the production of OMV in this strain. We further observed that strain TK1402 did not form thick biofilms in Brucella broth supplemented with 0.2% beta-cyclodextrin. However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation. Conclusion: The results suggested that OMV produced from TK1402 play an important role in biofilm formation in strain TK1402.