title: Acidogenicity of dual-species biofilms of bifidobacteria and Streptococcus mutans.
abstract: OBJECTIVE
  The aim of this study was to evaluate the acidogenicity of dual-species biofilms of bifidobacteria and Streptococcus mutans.
  
  
  METHODS
  The following strains were tested: Bifidobacterium dentium DSM20436, Parascardovia denticolens DSM10105, and Scardovia inopinata DSM10107. Streptococcus mutans UA159 and Lactobacillus acidophilus ATCC4356 were used as control. Bifidobacteria were studied planktonically as they were not able to form monospecies biofilm, they were grown in biofilms associated with S. mutans. Endogenous polysaccharide reserves of cultures at log phase were depleted. Standardized suspensions of the microorganisms were incubated in growth media supplemented with 10 mM glucose, lactose, raffinose, glucose, or xylitol. S. mutans biofilms were grown on glass cover slips for 24 h to which bifidobacteria were added. After 24 h, the dual-species biofilms were exposed to the same carbon sources, and after 3 h, the pH of spent culture media and concentrations of organic acids were measured. Statistical analyses were carried out using ANOVA and Tukey's test (α = 0.05).
  
  
  RESULTS
  A higher pH drop was observed when S. mutans was associated with P. denticolens or S. inopinata, in either planktonic or biofilm cultures, than with S. mutans alone. Bifidobacteria showed a higher pH drop in the presence of raffinose than S. mutans or L. acidophilus.
  
  
  CONCLUSIONS
  Dual-species biofilms of bifidobacteria and S. mutans produced more acid and greater pH drops than biofilms of S. mutans alone.
  
  
  CONCLUSIONS
  New insights on the complex process of caries pathogenicity contribute to the establishment of preventive and therapeutic measures, in particular in specific cases, such as in early childhood caries.
authors.affiliation: Environmental Engineering Department, São José dos Campos Institute of Science and Technology, UNESP, Univ. Estadual Paulista, Avenida Engenheiro Francisco Jose Longo 777, São José dos Campos, 12245-000, São Paulo, Brazil.|UNIVASF, Univ. Federal do Vale do São Francisco, Rua da Alvorada, General Dutra, Paulo Afonso, BA, 48607-190, Brazil.
authors.forename: Bruno Mello
authors.initials: BM
authors.lastname: de Matos
authors.affiliation: Araraquara School of Dentistry, UNESP, Univ. Estadual Paulista, Rua Humaitá, 1680, Centro, Araraquara, SP, 14801-385, Brazil.
authors.forename: Fernanda Lourenção
authors.initials: FL
authors.lastname: Brighenti
authors.affiliation: School of Dentistry, Faculty of Medicine and Health, University of Leeds, Leeds, UK.|Division of Oral Biology, Wellcome Trust Brenner Building, Level 7, St James's University Hospital Campus, Leeds, LS9 7TF, UK.
authors.forename: Thuy
authors.initials: T
authors.lastname: Do
authors.affiliation: Dental Institute, King's College London, Bessemer Rd., Denmark Hill, London, SE5 9RW, UK.
authors.forename: David
authors.initials: D
authors.lastname: Beighton
authors.affiliation: Environmental Engineering Department, São José dos Campos Institute of Science and Technology, UNESP, Univ. Estadual Paulista, Avenida Engenheiro Francisco Jose Longo 777, São José dos Campos, 12245-000, São Paulo, Brazil. cristiane@fosjc.unesp.br.|Oral Biopathology Graduate Program, São José dos Campos Institute of Science and Technology, Avenida Engenheiro Francisco Jose Longo 777, São José dos Campos, 12245-000, Brazil. cristiane@fosjc.unesp.br.
authors.forename: Cristiane Yumi
authors.initials: CY
authors.lastname: Koga-Ito
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000254:growth & development*; D018441:Biofilms / Q000254:growth & development*; D018929:Cell Culture Techniques; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D007779:Lactobacillus acidophilus; D013295:Streptococcus mutans / Q000254:growth & development*
chemical_list: D003470:Culture Media
keywords: Acidogenicity; Bifidobacteria; Biofilms; Dental caries