Assessment of in vitro biofilm formation by Helicobacter pylori

Background and Aims: Biofilms are surface-bound communities of bacterial cells that are implicated in their survival. As with various bacteria studied to date, Helicobacter pylori can have an alternate lifestyle as a biofilm. We previously reported that strain TK1402 showed a strong biofilm-forming ability in vitro. However, the mechanisms of its biofilm development remain unclear. We analyzed the basic characteristics of the biofilm-forming ability in strain TK1402. Methods: In order to characterize the biofilm-forming ability of the H. pylori strains, auto-aggregation, motility and hydrophobicity, which are important factors in biofilm formation by other bacteria, were analyzed. Further, we tested whether cell growth participated in biofilm formation in strain TK1402. Results: There were no significant differences in the auto-aggregation, motility and hydrophobicity of strain TK1402 compared with the other strains. On the other hand, pre-culture of this strain for 24-48 h resulted in decreased biofilm formation. Conclusion: TK1402 is a strong biofilm-forming strain of H. pylori in Brucella broth supplemented with 7% fetal calf serum. It is possible that biofilm-forming cell growth is a principal factor in biofilm development.