No abstract available.
Fusobacterium nucleatum* ; Fusobacterium* ; Immunization* ; Porphyromonas gingivalis* ; Porphyromonas*

No abstract available.
Biofilms* ; Fusobacterium nucleatum* ; Fusobacterium* ; Porphyromonas gingivalis* ; Porphyromonas*

Adhesins, Bacterial ; Biomedical Research ; Fusobacterium nucleatum

The purpose of this study was to isolate and characterize the Fusobacterium nucleatum (F. nucleatum) from subgingival plaque in Korean periodontitis patients. The subgingival plaque samples of periodontitis patient were collected with sterilized paper point. The paper point was put into reduced transfer medium and then immediately transferred to laboratory. The subgingival samples were diluted by 10,000 folds and plated on F. nucleatum-selective media agar plate. The plates were incubated at 37degrees C in an anaerobic chamber for 3 days. The violet-colored colonies were selected and subjected to further verification whether those are F. nucleatum or not. For further confirmation, 16S rRNA genes (rDNA) were cloned from each of bacterial clones and determined sequence of 16S rDNA. In this study, we found 17 distinct clinical isolates of F. nucleatum from subgingival plaque. The clinical isolates will be a useful in various studies in periodontology.
Agar ; Clone Cells ; DNA, Ribosomal ; Fusobacterium nucleatum* ; Fusobacterium* ; Genes, rRNA ; Humans ; Periodontitis

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T and B lymppocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate immunomodulatory effect of exposure to Fusobacterium nucleatum(F. nucleatum) prior to Porphyromonas gingivalis(P.gingivalis). Group 1(control) mice were immunized with phosphate-buffered saline, Group 2 were immunized with F. nucleatum prior to P. gingivalis, while Group 3 were immunized P. gingivalis alone. All the T cell clones derived from Group 2 demonstrated type 2 helper T cell clone(Th2 subsets), while those from Group 3 mice demonstrated Th1 subsets. Exposure of mice to F. nucleatum prior to P. gingivalis interfered with opsonophagocytosis function of sera against P. gingivalis. In adoptive T cell transfer experiments, in vivo protective capacity type 2 helper T cell clones(Th2) from Group 2 was significantly lower than type 1 helper T cell clones(Th1) from Group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated the different pattern of recognition of P. gingivalis fimbrial proteins between sera from Group 2 and Group 3. In conclusion, these study suggest that colonization of the subgingival niche by F. nucleatum prior to the periodontal pathogen, P. gingivalis, modulates the host immune responses to P. gingivalis at humoral, cellular and molecular levels.
Animals ; Blotting, Western ; Clone Cells ; Colon ; Fusobacterium nucleatum* ; Fusobacterium* ; Gingivitis ; Immunization ; Mice* ; Models, Animal ; Periodontal Diseases ; Porphyromonas gingivalis* ; Porphyromonas*

PURPOSE: The goal of this study was to develop and validate a standardized in vitro pathogenic biofilm attached onto saliva-coated surfaces. METHODS: Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) strains were grown under anaerobic conditions as single species and in dual-species cultures. Initially, the bacterial biomass was evaluated at 24 and 48 hours to determine the optimal timing for the adhesion phase onto saliva-coated polystyrene surfaces. Thereafter, biofilm development was assessed over time by crystal violet staining and scanning electron microscopy. RESULTS: The data showed no significant difference in the overall biomass after 48 hours for P. gingivalis in single- and dual-species conditions. After adhesion, P. gingivalis in single- and dual-species biofilms accumulated a substantially higher biomass after 7 days of incubation than after 3 days, but no significant difference was found between 5 and 7 days. Although the biomass of the F. nucleatum biofilm was higher at 3 days, no difference was found at 3, 5, or 7 days of incubation. CONCLUSIONS: Polystyrene substrates from well plates work as a standard surface and provide reproducible results for in vitro biofilm models. Our biofilm model could serve as a reference point for studies investigating biofilms on different surfaces.
Bacterial Adhesion ; Biofilms ; Biomass ; Fusobacterium nucleatum ; Fusobacterium ; Gentian Violet ; In Vitro Techniques ; Microscopy, Electron, Scanning ; Polystyrenes ; Porphyromonas gingivalis ; Porphyromonas

Fusobacterium nucleatum (F. nucleatum) is an early pathogenic colonizer in periodontitis, but the host response to infection with this pathogen remains unclear. In this study, we built an F. nucleatum infectious model with human periodontal ligament stem cells (PDLSCs) and showed that F. nucleatum could inhibit proliferation, and facilitate apoptosis, ferroptosis, and inflammatory cytokine production in a dose-dependent manner. The F. nucleatum adhesin FadA acted as a proinflammatory virulence factor and increased the expression of interleukin(IL)-1β, IL-6 and IL-8. Further study showed that FadA could bind with PEBP1 to activate the Raf1-MAPK and IKK-NF-κB signaling pathways. Time-course RNA-sequencing analyses showed the cascade of gene activation process in PDLSCs with increasing durations of F. nucleatum infection. NFκB1 and NFκB2 upregulated after 3 h of F. nucleatum-infection, and the inflammatory-related genes in the NF-κB signaling pathway were serially elevated with time. Using computational drug repositioning analysis, we predicted and validated that two potential drugs (piperlongumine and fisetin) could attenuate the negative effects of F. nucleatum-infection. Collectively, this study unveils the potential pathogenic mechanisms of F. nucleatum and the host inflammatory response at the early stage of F. nucleatum infection.
Humans ; Fusobacterium nucleatum/metabolism* ; NF-kappa B/metabolism* ; Periodontal Ligament/metabolism* ; Signal Transduction ; Fusobacterium Infections/pathology* ; Stem Cells/metabolism*

We evaluated the ability of lactic acid bacteria, Weissella cibaria, isolated from the oral cavity to adhere to epithelial cells. W. cibaria efficiently adhered to KB cells and HeLa cells. In addition, W. cibaria efficiently adhered to Fusobacterium nucleatum. But the adhesiveness of W. cibaria disappeared upon exposure to LiCl or pronase, suggesting that the S-layer proteins of W. cibaria mediated the adhesiveness. The molecular mass of the S-layer proteins extracted from W. cibaria was approximately 50 kDa. When W. cibaria strains were washed with 0.45% saline, the bacteria were efficiently adhered to the epithelial cells. In conclusion, W. cibaria has the ability to adhere to epithelial cells through the S-layer proteins.
Adhesiveness ; Bacteria ; Epithelial Cells* ; Fusobacterium nucleatum ; HeLa Cells ; Humans ; KB Cells ; Lactic Acid ; Mouth ; Pronase ; Weissella*

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.
Aggregatibacter actinomycetemcomitans ; Amoxicillin ; Anti-Bacterial Agents* ; Bacteria ; Doxycycline ; Fusobacterium nucleatum ; Metronidazole ; Penicillins ; Porphyromonas gingivalis ; Tetracycline

Most oral microorganisms exist as biofilms which initiate formation via the attachment of an early colonizer to host proteins on the tooth surface. Fusobacterium nucleatum act as a bridge between early and late colonizers. Dental biofilms eventually comprise dental pathogens such as Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. To evaluate the effects of mutual interactions between oral bacteria on the growth of biofilms, periodontopathogens were co-cultured with a 0.4 microm barrier. Streptococcus gordonii inhibited the growth of F. nucleatum and periodontopathogens. However, F. nucleatum, P. gingivalis and T. denticola activated the growth of other bacteria. A co-culture system of early and late colonizers could be a useful tool to further understand bacterial interactions during the development of dental biofilm.
Bacteria ; Biofilms ; Coculture Techniques ; Colon ; Forsythia ; Fusobacterium nucleatum ; Porphyromonas gingivalis ; Proteins ; Streptococcus gordonii ; Tooth ; Treponema denticola