title: Actinomyces naeslundii GroEL-dependent initial attachment and biofilm formation in a flow cell system.
abstract: Actinomyces naeslundii is an early colonizer with important roles in the development of the oral biofilm. The effects of butyric acid, one of short chain fatty acids in A. naeslundii biofilm formation was observed using a flow cell system with Tryptic soy broth without dextrose and with 0.25% sucrose (TSB sucrose). Significant biofilms were established involving live and dead cells in TSB sucrose with 60mM butyric acid but not in concentrations of 6, 30, 40, and 50mM. Biofilm formation failed in 60mM sodium butyrate but biofilm level in 60mM sodium butyrate (pH4.7) adjusted with hydrochloric acid as 60mM butyric media (pH4.7) was similar to biofilm levels in 60mM butyric acid. Therefore, butyric acid and low pH are required for significant biofilm formation in the flow cell. To determine the mechanism of biofilm formation, we investigated initial A. naeslundii colonization in various conditions and effects of anti-GroEL antibody. The initial colonization was observed in the 60mM butyric acid condition and anti-GroEL antibody inhibited the initial colonization. In conclusion, we established a new biofilm formation model in which butyric acid induces GroEL-dependent initial colonization of A. naeslundii resulting in significant biofilm formation in a flow system.
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Maxillofacial Surgery, Nihon University Graduate School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Arai
authors.affiliation: Department of Microbiology, Nihon University, School of Dentistry, Tokyo, Japan.
authors.forename: Kuniyasu
authors.initials: K
authors.lastname: Ochiai
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan. Electronic address: hsenpuku@nih.go.jp.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Senpuku
mesh_terms: D000190:Actinomyces / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D020148:Butyric Acid / Q000378:metabolism; D018834:Chaperonin 60 / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration
chemical_list: D018834:Chaperonin 60; D020148:Butyric Acid
keywords: Actinomyces naeslundii; Biofilm; Butyric acid; Flowcell system; GroEL; Initial attachment