title: The effect of inoculum source and fluid shear force on the development of in vitro oral multispecies biofilms.
abstract: OBJECTIVE
  Saliva has been previously used as an inoculum for in vitro oral biofilm studies. However, the microbial community profile of saliva is markedly different from hard- and soft-tissue-associated oral biofilms. Here, we investigated the changes in the biofilm architecture and microbial diversity of in vitro oral biofilms developed from saliva, tongue or plaque-derived inocula under different salivary shear forces.
  
  
  RESULTS
  Four inoculum types (saliva, bacteria harvested from the tongue, toothbrush and curette-harvested plaque) were collected and pooled. Biofilms (n ≥ 15) were grown for 20 h in cell-free human saliva flowing at three different shear forces. Stained biofilms were imaged using a confocal laser scanning microscope. Biomass, thickness and roughness were determined by image analysis and bacterial community composition analysed using Ion Torrent. All developed biofilms showed a significant reduction in observed diversity compared with their respective original inoculum. Shear force altered biofilm architecture of saliva and curette-collected plaque and community composition of saliva, tongue and curette-harvested plaque.
  
  
  CONCLUSIONS
  Different intraoral inocula served as precursors of in vitro oral polymicrobial biofilms which can be influenced by shear.
  
  
  CONCLUSIONS
  Inoculum selection and shear force are key factors to consider when developing multispecies biofilms within in vitro models.
authors.affiliation: Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.|Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Fernández
authors.affiliation: Scientific Discovery, Global Innovation Center (GIC), Wrigley, Chicago, IL, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Aspiras
authors.affiliation: Scientific Discovery, Global Innovation Center (GIC), Wrigley, Chicago, IL, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Dodds
authors.affiliation: Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: C
authors.initials: C
authors.lastname: González-Cabezas
authors.affiliation: Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Rickard
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000648:ultrastructure; D018441:Biofilms / Q000254:growth & development*; D001696:Biomechanical Phenomena; D003773:Dental Plaque / Q000382:microbiology*; D006801:Humans; D018613:Microscopy, Confocal; D009055:Mouth / Q000382:microbiology*; D012463:Saliva / Q000382:microbiology*; D033081:Shear Strength; D014059:Tongue / Q000382:microbiology*
keywords: 16S rRNA; bacteria; biodiversity; confocal laser scanning microscopy; dental plaque; microbiome; saliva; tongue