IADR Abstract Archives
Fusobacterium Nucleatum Subspecies Differ in Biofilm Forming Ability in Vitro
Objectives: This study aimed to evaluate mono-species biofilm formation in vitro using subspecies of Fusobacterium nucleatum, oral opportunistic pathogen associated with periodontitis. F. nucleatum acts as a bridging organism in complex subgingival biofilms. Five subspecies have been identified: animalis, fusiforme, nucleatum, polymorphum and vincentii. Differential subspecies-specific biofilm formation has been reported in multispecies biofilm models, however, formation of single-subspecies biofilms remains to be studied.
Methods: Single-subspecies biofilms were grown statically for three days on glass and plastic coverslips in multi-well plates. Coverslips were coated with agents known to promote cell attachment to culture surfaces: fibronectin, gelatin and poly-L-lysine. Additionally, untreated glass slides were modified by sandblasting (25µm grit size) to create roughened surfaces. Biomass formation was quantified using crystal violet staining. Coverslip coverage, as well as biofilm structure were analysed using fluorescence and scanning electron microscopy.
Results: Surface treatments had a differential effect on bacterial attachment and biofilm formation was determined by quantification by biofilm mass. Biofilm formation was at its lowest on sandblasted glass slides and highest with a poly-L-lysine coated surface. F. nucleatum ssp. polymorphum (ATCC 10953) consistently formed very low amounts of biofilm on all tested surfaces when compared to other subspecies.
Conclusions: Our results indicate that the ability of F. nucleatum to form single-subspecies biofilms in vitro is subspecies-specific, consistent with previous studies reporting differences in F. nucleatum integration into multispecies biofilms. Moreover, it is conceivable that not all subspecies are able to form stable single-subspecies biofilms. F. nucleatum ssp. polymorphum will be investigated further due to its limited ability to form biofilms. Understanding single-subspecies biofilm formation by F. nucleatum is important for future studies focusing on virulence and immunogenicity of biofilm-resident subspecies. This, in turn, may provide novel insights into prevention and treatment of periodontitis and associated F. nucleatum-related systemic diseases.
Methods: Single-subspecies biofilms were grown statically for three days on glass and plastic coverslips in multi-well plates. Coverslips were coated with agents known to promote cell attachment to culture surfaces: fibronectin, gelatin and poly-L-lysine. Additionally, untreated glass slides were modified by sandblasting (25µm grit size) to create roughened surfaces. Biomass formation was quantified using crystal violet staining. Coverslip coverage, as well as biofilm structure were analysed using fluorescence and scanning electron microscopy.
Results: Surface treatments had a differential effect on bacterial attachment and biofilm formation was determined by quantification by biofilm mass. Biofilm formation was at its lowest on sandblasted glass slides and highest with a poly-L-lysine coated surface. F. nucleatum ssp. polymorphum (ATCC 10953) consistently formed very low amounts of biofilm on all tested surfaces when compared to other subspecies.
Conclusions: Our results indicate that the ability of F. nucleatum to form single-subspecies biofilms in vitro is subspecies-specific, consistent with previous studies reporting differences in F. nucleatum integration into multispecies biofilms. Moreover, it is conceivable that not all subspecies are able to form stable single-subspecies biofilms. F. nucleatum ssp. polymorphum will be investigated further due to its limited ability to form biofilms. Understanding single-subspecies biofilm formation by F. nucleatum is important for future studies focusing on virulence and immunogenicity of biofilm-resident subspecies. This, in turn, may provide novel insights into prevention and treatment of periodontitis and associated F. nucleatum-related systemic diseases.