title: Collagen-like peptide sequences inhibit bacterial invasion of root dentine.
abstract: OBJECTIVE
  To investigate the effects of peptides derived from the sequence of collagen to inhibit penetration of human or bovine dentine by species of streptococci and enterococci.
  
  
  METHODS
  Blocks of human or bovine root dentine were infected for 14 days with bacterial cultures, in the presence or absence of various collagen-like peptide sequences. Invasion of dentinal tubules was determined from microscopic images of histochemically stained dentine thin sections. Extent of invasion was expressed as tubule invasion index (TI), or tubule invasion factor (TIF) which, in addition to the density of invasion, took into account the depth of invasion. Data were analysed by two-way anova.
  
  
  RESULTS
  Streptococcus gordonii, Streptococcus mutans and Enterococcus faecalis were associated with heavy invasion (TI >2.5, TIF >4) of human or bovine root dentinal tubules, with E. faecalis being the most penetrative. Incorporation of peptides Gly-Pro-Ala or Gly-Pro-Hyp into the in vitro model system significantly reduced (P < 0.05) dentine invasion by the three species of highly invasive organisms. Inhibition of bacterial invasion by the peptides was dose dependent, and the peptides did not inhibit bacterial growth in culture.
  
  
  CONCLUSIONS
  Specific collagen-like peptide sequences inhibited the invasion of dentine in vitro by a range of oral bacteria. The peptides likely act as competitive inhibitors blocking bacterial collagen receptors and could potentially allow for target-specific control of dentine infections.
authors.affiliation: School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
authors.forename: J L
authors.initials: JL
authors.lastname: Brittan
authors.affiliation: School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
authors.forename: S V
authors.initials: SV
authors.lastname: Sprague
authors.affiliation: School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
authors.forename: S P
authors.initials: SP
authors.lastname: Huntley
authors.affiliation: School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
authors.forename: C N A
authors.initials: CN
authors.lastname: Bell
authors.affiliation: School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
authors.forename: H F
authors.initials: HF
authors.lastname: Jenkinson
authors.affiliation: Department of Oral Rehabilitation, University of Otago, Dunedin, New Zealand.
authors.forename: R M
authors.initials: RM
authors.lastname: Love
mesh_terms: D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D003804:Dentin / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000472:pathogenicity; D006801:Humans; D010455:Peptides / Q000737:chemistry; D013291:Streptococcus; D013295:Streptococcus mutans / Q000472:pathogenicity; D014092:Tooth Root / Q000382:microbiology*
chemical_list: D010455:Peptides; D003094:Collagen
keywords: Enterococcus; Streptococcus; bovine dentine; dentinal tubules; proline peptides