IADR Abstract Archives
Optimisation of in vitro Oral Biofilm Models Using Saliva Inoculum
Objectives: Oral biofilms have been previously studied in vitro using different substrates, inoculums, and incubation environments. The main disadvantages of in vitro replication of biofilms is the use of single or limited strains of bacteria as the initial inoculum, and artificial growth media. The aim of this study was to develop an in vitro biofilm model using human whole mouth saliva to represent the microbial diversity of the oral cavity, pasteurised whole mouth saliva as growth medium to simulate the complex mix of nutrients found in saliva, and hydroxyapatite (HA) discs to mimic the tooth surface.
Methods: Whole mouth saliva was collected and biofilms were grown on HA discs under two different conditions for 72 hours; (1) spun saliva inoculum grown at 37°C aerobically versus anaerobically (n=3), (2) spun versus unspun saliva inoculum grown at 37°C anaerobically (n=3). Depth and surface area coverage of the disc by bacterial biofilms was assessed at 24, 48 and 72 hours using live/dead staining and confocal laser scanning microscopy (CLSM).
Results: There was a significant difference in coverage of the disc between anaerobically and aerobically grown biofilms (p <0.01) with anaerobic discs having more coverage than aerobic discs, and no significant difference in depth of biofilms (p >0.05). There was no significant difference between coverage (p >0.05) and depth (p >0.05) of biofilms from spun or unspun saliva, indicating that the number of bacteria available for biofilm formation in spun and unspun saliva is comparable.
Conclusions: Based on these results, in vitro oral biofilm models grow aerobically and anaerobically from whole mouth saliva inoculum and growth medium.
Methods: Whole mouth saliva was collected and biofilms were grown on HA discs under two different conditions for 72 hours; (1) spun saliva inoculum grown at 37°C aerobically versus anaerobically (n=3), (2) spun versus unspun saliva inoculum grown at 37°C anaerobically (n=3). Depth and surface area coverage of the disc by bacterial biofilms was assessed at 24, 48 and 72 hours using live/dead staining and confocal laser scanning microscopy (CLSM).
Results: There was a significant difference in coverage of the disc between anaerobically and aerobically grown biofilms (p <0.01) with anaerobic discs having more coverage than aerobic discs, and no significant difference in depth of biofilms (p >0.05). There was no significant difference between coverage (p >0.05) and depth (p >0.05) of biofilms from spun or unspun saliva, indicating that the number of bacteria available for biofilm formation in spun and unspun saliva is comparable.
Conclusions: Based on these results, in vitro oral biofilm models grow aerobically and anaerobically from whole mouth saliva inoculum and growth medium.