title: Effects of short-chain fatty acids on Actinomyces naeslundii biofilm formation.
abstract: Actinomyces naeslundii is an early colonizer and has important roles in the development of the oral biofilm. Short-chain fatty acids (SCFA) are secreted extracellularly as a product of metabolism by gram-negative anaerobes, e.g. Porphyromonas gingivalis and Fusobacterium nucleatum; and the SCFA may affect biofilm development with interaction between A. naeslundii and gram-negative bacteria. Our aim was to investigate the effects of SCFA on biofilm formation by A. naeslundii and to determine the mechanism. We used the biofilm formation assay in 96-well microtiter plates in tryptic soy broth without dextrose and with 0.25% sucrose using safranin stain of the biofilm monitoring 492 nm absorbance. To determine the mechanism by SCFA, the production of chaperones and stress-response proteins (GrpE and GroEL) in biofilm formation was examined using Western blot fluorescence activity with GrpE and GroEL antibodies. Adding butyric acid (6.25 mm) 0, 6 and 10 h after beginning culture significantly increased biofilm formation by A. naeslundii, and upregulation was observed at 16 h. Upregulation was also observed using appropriate concentrations of other SCFA. In the upregulated biofilm, production of GrpE and GroEL was higher where membrane-damaged or dead cells were also observed. The upregulated biofilm was significantly reduced by addition of anti-GroEL antibody. The data suggest biofilm formation by A. naeslundii was upregulated dependent on the production of stress proteins, and addition of SCFA increased membrane-damaged or dead cells. Production of GroEL may physically play an important role in biofilm development.
authors.affiliation: Department of Bacteriology, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yoneda
authors.forename: T
authors.initials: T
authors.lastname: Kawarai
authors.forename: N
authors.initials: N
authors.lastname: Narisawa
authors.forename: E B
authors.initials: EB
authors.lastname: Tuna
authors.forename: N
authors.initials: N
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Tsugane
authors.forename: Y
authors.initials: Y
authors.lastname: Saeki
authors.forename: K
authors.initials: K
authors.lastname: Ochiai
authors.forename: H
authors.initials: H
authors.lastname: Senpuku
mesh_terms: D000190:Actinomyces / Q000187:drug effects* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D015153:Blotting, Western; D020148:Butyric Acid / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects; D018834:Chaperonin 60 / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D005232:Fatty Acids, Volatile / Q000494:pharmacology*; D006360:Heat-Shock Proteins / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability / Q000187:drug effects; D010421:Pentanoic Acids / Q000494:pharmacology; D011422:Propionates / Q000494:pharmacology; D013291:Streptococcus / Q000187:drug effects; D034366:Streptococcus anginosus / Q000187:drug effects; D054773:Streptococcus gordonii / Q000187:drug effects; D034361:Streptococcus mitis / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D016986:Streptococcus sobrinus / Q000187:drug effects; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D005232:Fatty Acids, Volatile; C068113:GrpE protein, Bacteria; D006360:Heat-Shock Proteins; D010421:Pentanoic Acids; D011422:Propionates; D020148:Butyric Acid; C038780:n-pentanoic acid; C029658:propionic acid
keywords: Actinomyces naeslundii; GroEL; biofilm; butyric acid; short chain fatty acid