title: Live and heat-killed Lactobacillus spp. interfere with Streptococcus mutans and Streptococcus oralis during biofilm development on titanium surface.
abstract: OBJECTIVE
  This research investigates the ability of live and heat-killed (HK) Lactic Acid Bacteria (LAB) to interfere with Streptococcus mutans ATCC 25175 and Streptococcus oralis ATCC 9811 during biofilm formation.
  
  
  METHODS
  Eight Lactobacillus spp. and two oral colonizers, pathogenic Streptococcus mutans and resident Streptococcus oralis, were characterized for their aggregation abilities, cell surface properties and biofilm formation ability on titanium surface. Then, the interference activity of selected live and HK Lactobacillus spp. during S. mutans and S. oralis biofilm development were performed. The cell-free culture supernatants (CFCS) anti-biofilm activity was also determined.
  
  
  RESULTS
  LAB possess good abilities of auto-aggregation (from 14.19 to 28.97%) and of co-aggregation with S. oralis. The cell-surfaces characteristics were most pronounced in S. mutans and S. oralis, while the highest affinities to xylene and chloroform were observed in Lactobacillus rhamnosus ATCC 53103 (56.37%) and Lactobacillus paracasei B21060 (43.83%). S. mutans and S. oralis developed a biofilm on titanium surface, while LAB showed a limited or no ability to create biofilm. Live and HK L. rhamnosus ATCC 53103 and L. paracasei B21060 inhibited streptococci biofilm formation by competition and displacement mechanisms with no substantial differences. The CFCSs of both LAB strains, particularly the undiluted one of L. paracasei B21060, decreased S. mutans and S. oralis biofilm formation.
  
  
  CONCLUSIONS
  This study evidenced the association of LAB aggregation abilities and cell-surface properties with the LAB-mediated inhibition of S. mutans and S. oralis biofilm formation. Lactobacilli showed different mechanisms of action and peculiar strain-specific characteristics, maintained also in the heat-killed LAB.
authors.affiliation: Department of Translational Research, New Technologies in Medicine Surgery, University of Pisa, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Ciandrini
authors.affiliation: Department of Biomolecular Sciences, Division of Toxicological, Hygiene and Environmental Sciences, University of Urbino "Carlo Bo", via S. Chiara 27, 61029 Urbino, PU, Italy. Electronic address: raffaella.campana@uniurb.it.
authors.forename: R
authors.initials: R
authors.lastname: Campana
authors.affiliation: Department of Biomolecular Sciences, Division of Toxicological, Hygiene and Environmental Sciences, University of Urbino "Carlo Bo", via S. Chiara 27, 61029 Urbino, PU, Italy.
authors.forename: W
authors.initials: W
authors.lastname: Baffone
mesh_terms: D000898:Antibiosis; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D006358:Hot Temperature; D007778:Lactobacillus / Q000502:physiology*; D013295:Streptococcus mutans / Q000254:growth & development*; D019533:Streptococcus oralis / Q000254:growth & development*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D014025:Titanium
keywords: Aggregation ability; Biofilm formation inhibition; Cell-surface characteristics; Live and heat-killed Lactobacillus spp; Oral streptococci