title: Biofilm formation by a fimbriae-deficient mutant of Actinobacillus actinomycetemcomitans.
abstract: Actinobacillus actinomycetemcomitans strain 310-TR produces fimbriae and forms a tight biofilm in broth cultures, without turbid growth. The fimbriae-deficient mutant 310-DF, constructed in this study, was grown as a relatively fragile biofilm at the bottom of a culture vessel. Scanning electron microscopy revealed that on glass coverslips, 310-TR formed tight and spherical microcolonies, while 310-DF produced looser ones. These findings suggest that fimbriae are not essential for the surface-adherent growth but are required for enhancing cell-to-surface and cell-to-cell interactions to stabilize the biofilm. Treatment of the 310-DF biofilm with either sodium metaperiodate or DNase resulted in significant desorption of cells from glass surfaces, indicating that both carbohydrate residues and DNA molecules present on the cell surface are also involved in the biofilm formation.
authors.affiliation: Department of Oral Microbiology, Okayama University Graduate School of Medicine and Dentistry, Japan. inouet@cc.okayama-u.ac.jp
authors.forename: Tetsuyoshi
authors.initials: T
authors.lastname: Inoue
authors.forename: Ryuji
authors.initials: R
authors.lastname: Shingaki
authors.forename: Norio
authors.initials: N
authors.lastname: Sogawa
authors.forename: Chiharu Aoki
authors.initials: CA
authors.lastname: Sogawa
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Asaumi
authors.forename: Susumu
authors.initials: S
authors.lastname: Kokeguchi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Fukui
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics / Q000502:physiology*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D036781:Fimbriae Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D036781:Fimbriae Proteins