Combating Cariogenic Streptococcus mutans Biofilm Formation and Disruption with Coumaric Acid on Dentin Surface

Area of Science:

• Microbiology
• Biochemistry
• Materials Science

Background:

• Streptococcus mutans is the primary causative agent of dental caries.
• Dental caries pathogenesis is linked to S. mutans' ability to form robust biofilms (dental plaque).
• Controlling S. mutans biofilms is crucial for preventing and treating dental caries.

Purpose of the Study:

• To investigate the efficacy of Coumaric acid (CA) in controlling Streptococcus mutans biofilm formation.
• To evaluate the potential of CA in dispersing preformed S. mutans biofilms on dentin surfaces.
• To analyze the impact of CA on bacterial growth, viability, and extracellular polymeric substances (EPS) production.

Main Methods:

• Biofilm assays including MTT viability assay and microtiter plate assay.
• Quantification of extracellular polymeric substances (EPS) including polysaccharides and proteins.
• Microscopy techniques (fluorescence microscopy, 3D surface plots) for biofilm biomass and surface coverage analysis.
• Molecular docking simulations to predict CA-receptor interactions.

Main Results:

• CA significantly reduced S. mutans growth (98.37% at 1 mg/mL) and biofilm formation (95.48%).
• CA effectively dispersed preformed biofilms (73.45% reduction) and decreased bacterial viability (73.44%).
• CA treatment led to significant reductions in EPS (polysaccharides and proteins) and biofilm mass/surface coverage.

Conclusions:

• Coumaric acid exhibits potent antibacterial and anti-biofilm properties against Streptococcus mutans.
• CA demonstrates potential as a therapeutic agent for managing dental plaque and preventing dental caries.
• Molecular docking suggests specific interactions of CA with S. mutans competence-stimulating peptide, providing mechanistic insights.