Effect of surface chemistry on bacterial adhesion, viability, and morphology

Helicobacter pylori (H. pylori) is one of the most common infectious agents in the world and it is thought to colonize the gastric mucosa of about half of the world's population causing several gastric diseases. In this work, the effect of surface chemistry on H. pylori nonspecific adhesion, viability, and morphology was evaluated using three H. pylori strains with different adhesins expression profile. Self-assembled monolayers (SAMs) of alkanethiols on gold were used to obtain surfaces exposing different functional groups: OH, CH3, and ethylene glycol (EG4). Bacterial adhesion onto the surfaces reached a plateau at 2 h. There was a correlation between adhesion and the exposed surface group, with bacterial cells adhering preferentially to CH3-SAMs while EG4-SAMs prevented H. pylori adhesion during the entire adhesion test (24 h). Surfaces that presented the EG4 group were also the only ones that significantly reduced the viability of adhered bacteria. Surface chemistry also influenced the morphology of adhered bacteria. The H. pylori rod shape observed in the control (Tissue Culture Polyethylene-TCPE) was only retrieved on CH3-SAMs. This work demonstrates that surface chemistry, namely specific functional groups on the material, influence the nonspecific adsorption of H. pylori. Moreover, the features of the bacterial strain and the surface chemistry can alter the adhesion kinetics, as well as the morphology and viability of attached bacteria.