Saliva-coated titanium biosensor detects specific bacterial adhesion and bactericide caused mass loading upon cell...

Area of Science:

• Biomaterials Science
• Microbiology
• Surface Science

Background:

• Bacteria on medical devices cause infections, with Streptococcus gordonii initiating oral biofilms and contributing to infective endocarditis.
• Understanding early biomaterial-bacteria interactions and antibacterial effects is crucial for preventing device-associated infections.

Purpose of the Study:

• To investigate in situ the specific binding mechanisms of Streptococcus gordonii to saliva-coated titanium biosensors.
• To analyze the impact of antibacterial agents on bacterial film properties and cellular integrity using quartz crystal microbalance with dissipation monitoring (QCM-D).

Main Methods:

• Utilized a saliva-coated titanium biosensor and QCM-D to monitor real-time interactions.
• Applied a clinically relevant antibacterial agent (mouth rinse with chlorhexidine and cetylpyridinium chloride) to assess its effects on adhered bacteria.
• Correlated QCM-D data with microscopic observations of bacterial films.

Main Results:

• Observed specific binding patterns of S. gordonii to saliva-coated titanium, distinct from unspecific adhesion to pure titanium.
• Detected an increase in dissipative mass upon antibacterial treatment, indicating bacterial cell leakage and damage.
• Mass loss effects during initial biofilm formation suggested punctual, specific bacterial adhesion.

Conclusions:

• QCM-D can differentiate specific bacterial adhesion mechanisms on biomaterials.
• The study demonstrates acoustic sensing of bacterial cell wall rupture and membrane damage induced by antibacterial agents.
• Findings have implications for developing novel strategies to combat biomaterial-associated infections and assess antibacterial efficacy.