IADR Abstract Archives
Characterization of honey-derived exosomes and their oral antibiofilm effect.
Objectives: Honeybee Apis mellifera derived products are known to be antibacterial and pro-regenerative. However, the mechanisms underlying these effects remain unknown. Recently, it has been shown that honey contains exosome-like vesicles (ELV) with strong antibacterial and biofilm inhibiting effects against Staphylococcus aureus. However, the effect of these ELVs on oral biofilm growth remains unknown. Thus, the aim of our study was to analyze the biofilm-inhibiting effects of honey ELVs (H-ELVs) on relevant oral streptococcal strains.
Methods: H-ELVs were isolated by ultracentrifugation and analyzed concerning their size distribution using Nanoparticle Tracking Analysis (NTA). Streptococcus mutans (UA159) and Streptococcus sanguinis SK36 were chosen to assess antibiotic and biofilm-inhibiting effects. 5x104 CFU were incubated with different concentrations of H-ELVs (0.1:1, 1:1, 10:1, 100:1 H-ELVs per CFU), in a microplate biofilm assay, and biofilm inhibition was assessed after 24hrs.
Results: Transmission Electron Microscopy confirmed the presence of ELVs, and NTA revealed that the mean size of H-ELVs was 176.2 nm and mode 137.1 nm. It was found that for S. mutans, concentrations of around 1:1 H-ELV to CFU are sufficient to exert growth- and biofilm inhibition, while S. sanguinis growth was not inhibited at these concentrations.
Conclusions: This is the first study reporting antibiofilm effects of H-ELVs in oral streptococci. Future work includes the characterization of relevant H-ELV cargo and potential mechanisms explaining these observations. With H-ELVs also displaying the advantages of being easily accessible and from a cost-effective source, we propose H-ELVs as a promising novel strategy for biofilm control in the oral cavity.
Methods: H-ELVs were isolated by ultracentrifugation and analyzed concerning their size distribution using Nanoparticle Tracking Analysis (NTA). Streptococcus mutans (UA159) and Streptococcus sanguinis SK36 were chosen to assess antibiotic and biofilm-inhibiting effects. 5x104 CFU were incubated with different concentrations of H-ELVs (0.1:1, 1:1, 10:1, 100:1 H-ELVs per CFU), in a microplate biofilm assay, and biofilm inhibition was assessed after 24hrs.
Results: Transmission Electron Microscopy confirmed the presence of ELVs, and NTA revealed that the mean size of H-ELVs was 176.2 nm and mode 137.1 nm. It was found that for S. mutans, concentrations of around 1:1 H-ELV to CFU are sufficient to exert growth- and biofilm inhibition, while S. sanguinis growth was not inhibited at these concentrations.
Conclusions: This is the first study reporting antibiofilm effects of H-ELVs in oral streptococci. Future work includes the characterization of relevant H-ELV cargo and potential mechanisms explaining these observations. With H-ELVs also displaying the advantages of being easily accessible and from a cost-effective source, we propose H-ELVs as a promising novel strategy for biofilm control in the oral cavity.