title: Growth dynamics in a natural biofilm and its impact on oral disease management.
abstract: Measurements of the microbial growth dynamics in natural biofilm communities are almost non-existent. In a recent study, the biofilm formation on teeth was examined. A previously unknown active period of bacterial division occurred at a certain density of plaque bacteria on tooth enamel. The density-dependent cell-division phase of plaque formation contributed 90% of the biomass in the first 24 hrs of plaque formation. This suggested that growth was induced by the bacteria. In vitro assays were developed for rapid evaluation of the growth of surface-linked bacteria by the measurement of cellular components associated with growth on a per cell per time basis. Cell-free supernatants (termed START) of media in contact with bacteria were assayed for their effects on DNA synthesis and other cellular components associated with growth. START was found to increase the incorporation of [3H-methyl]-thymidine on a per cell per time basis, when compared with media not in contact with bacteria. Additional in vivo studies and in situ-based models of complex biofilms are needed if all of the mechanisms involved in the rapid accumulation of biofilm bacteria on teeth and other surfaces are to be understood.
authors.affiliation: Department of Diagnostic and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis 55455-0329, USA.
authors.forename: W F
authors.initials: WF
authors.lastname: Liljemark
authors.forename: C G
authors.initials: CG
authors.lastname: Bloomquist
authors.forename: B E
authors.initials: BE
authors.lastname: Reilly
authors.forename: C J
authors.initials: CJ
authors.lastname: Bernards
authors.forename: D W
authors.initials: DW
authors.lastname: Townsend
authors.forename: A T
authors.initials: AT
authors.lastname: Pennock
authors.forename: J L
authors.initials: JL
authors.lastname: LeMoine
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D001422:Bacterial Adhesion; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D002455:Cell Division / Q000502:physiology; D015169:Colony Count, Microbial / Q000379:methods; D003470:Culture Media; D004269:DNA, Bacterial / Q000096:biosynthesis; D003773:Dental Plaque / Q000382:microbiology*; D017753:Ecosystem; D006801:Humans; D012463:Saliva / Q000737:chemistry / Q000382:microbiology / Q000502:physiology; D013291:Streptococcus / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D003470:Culture Media; D004269:DNA, Bacterial