title: Behavior of two Tannerella forsythia strains and their cell surface mutants in multispecies oral biofilms.
abstract: As a member of subgingival multispecies biofilms, Tannerella forsythia is commonly associated with periodontitis. The bacterium has a characteristic cell surface (S-) layer modified with a unique O-glycan. Both the S-layer and the O-glycan were analyzed in this study for their role in biofilm formation by employing an in vitro multispecies biofilm model mimicking the situation in the oral cavity. Different T. forsythia strains and mutants with characterized defects in cell surface composition were incorporated into the model, together with nine species of select oral bacteria. The influence of the T. forsythia S-layer and attached glycan on the bacterial composition of the biofilms was analyzed quantitatively using colony-forming unit counts and quantitative real-time polymerase chain reaction, as well as qualitatively by fluorescence in situ hybridization and confocal laser scanning microscopy. This revealed that changes in the T. forsythia cell surface did not affect the quantitative composition of the multispecies consortium, with the exception of Campylobacter rectus cell numbers. The localization of T. forsythia within the bacterial agglomeration varied depending on changes in the S-layer glycan, and this also affected its aggregation with Porphyromonas gingivalis. This suggests a selective role for the glycosylated T. forsythia S-layer in the positioning of this species within the biofilm, its co-localization with P. gingivalis, and the prevalence of C. rectus. These findings might translate into a potential role of T. forsythia cell surface structures in the virulence of this species when interacting with host tissues and the immune system, from within or beyond the biofilm.
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Vienna, Vienna, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Bloch
authors.affiliation: Division of Oral Microbiology and Immunology, Institute of Oral Biology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Thurnheer
authors.affiliation: Department of Oral Microbiology, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Division of Cariology and Endodontics, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden.
authors.forename: Georgios N
authors.initials: GN
authors.lastname: Belibasakis
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Vienna, Vienna, Austria.
authors.forename: Christina
authors.identifier: 0000-0003-1613-7258
authors.initials: C
authors.lastname: Schäffer
mesh_terms: D018441:Biofilms; D044883:Campylobacter rectus / Q000302:isolation & purification / Q000502:physiology; D002462:Cell Membrane / Q000235:genetics*; D005881:Gingiva / Q000382:microbiology; D006031:Glycosylation; D056265:Microbial Interactions; D009055:Mouth / Q000382:microbiology; D009154:Mutation; D010510:Periodontal Diseases / Q000382:microbiology; D010518:Periodontitis / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000302:isolation & purification / Q000502:physiology; D018713:Prevotella intermedia / Q000302:isolation & purification / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D000070436:Tannerella forsythia / Q000235:genetics* / Q000378:metabolism*; D048373:Treponema denticola / Q000302:isolation & purification / Q000502:physiology; D014774:Virulence
keywords: 
  Campylobacter rectus
  ; 
  Tannerella forsythia
  ; S-layer glycosylation; cell surface; oral biofilm; periodontal disease