Streptococcus mutans adhesion force sensing in multi-species oral biofilms
Can Wang1, Henny C van der Mei2, Henk J Busscher3
1Department of Orthodontics, W.J. Kolff Institute, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
NPJ Biofilms and Microbiomes
|June 26, 2020
Summary
Bacteria sense surfaces through mechanical forces. Salivary films change these forces, but live initial colonizers help bacteria regain surface sensing for adaptation in oral biofilms.
Area of Science:
- Microbiology
- Biophysics
- Oral Biology
Background:
- Bacteria mechanically sense their environment through pressure changes from adhesion forces.
- Streptococcus mutans biofilm properties depend on sensed adhesion forces.
- The influence of salivary-conditioning film (SCF) and multi-species interactions on bacterial adhesion sensing is unclear.
Purpose of the Study:
- To investigate how SCF adsorption and oral biofilm composition affect S. mutans adhesion force sensing.
- To determine the impact on S. mutans gene expression related to adhesion sensing.
Main Methods:
- Atomic force microscopy (AFM) to measure S. mutans adhesion forces.
- RT-qPCR to quantify S. mutans gene expression.
- Optical coherence tomography (OCT) to visualize biofilm structure.
Main Results:
- SCF adsorption altered S. mutans adhesion forces, decreasing them on hydrophobic and increasing them on hydrophilic surfaces.
- S. mutans showed no differential adhesion sensing on SCF-coated surfaces with dead S. oralis.
- Live S. oralis enabled S. mutans adhesion force sensing and gene expression similar to non-SCF surfaces.
Conclusions:
- Live initial colonizers like S. oralis may degrade SCF, enabling direct contact and surface sensing by S. mutans.
- This process allows S. mutans to adapt its response based on underlying surface properties.
- Initial colonizers play a novel role in mediating surface sensing within multi-species oral biofilms.
