• Korean Journal of Microbiology
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• v.53 no.3
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• pp.219-221
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• 2017

Fusobacterium nucleatum is a Gram-negative, obligately anaerobic and rod- or filament-shaped bacterium. F. nucleatum is part of oral microflora and is a causative agent of periodontitis as well as is associated with a wide spectrum of systemic diseases of human. F. nucleatum KCOM 1323 (= ChDC F317) was isolated from a human subgingival plaque of periodontitis lesion. Here, we present the complete genome sequence of F. nucleatum KCOM 1323.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.33-40
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• 2003

Fusobacterium nucleatum, one of the bacteria causing halitosis, produces the volatile sulfur compounds (VSC) such as $H_2S$ in the media containing sulfur components, and forms FeS by binding with iron component. The various factors of oral cavity affect the concentration of sulfur compounds produced by Fusobacterium nucleatum. In this study, the effect of nutrients and pH on the production of sulfur compounds by Fusobacterium nucleatum was studied with the following results. 1. The optical density of broth was increased to $0.817{\pm}0.032$ and $1.297{\pm}0.024$ by adding 1.0% sodium thiosulfate and 0.05% L-cysteine hydrochloride in the media, respectively. 2. Though the optical density of broth was $0.799{\pm}0.032$ by adding volatile sulfur compounds (VSC) only in the media, it was increased to $1.775{\pm}0.003$ and $1.648{\pm}0.022$ by adding xylitol combined with glucose and fructose, respectively. 3. The concentration of VSC was above 20,000 ppb in the media above pH 5.5. The optical density of broth was still high in the media with L-cysteine hydrochloride of higher concentration, being low in the media of lower pH. 4. The concentration of VSC was high when there was distilled water or saline solution on the media, and their amount was small. These results suggest that the production of sulfur compounds by Fusobacterium nucleatum was inhibited by xylitol and acid.

• Journal of Korean society of Dental Hygiene
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• v.6 no.4
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• pp.311-324
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• 2006

The purpose of this investigation was to evaluate of the specificity of Fusobacterium nucleatum subspecies-specific DNA probes using dot blot hybridization. To confirm whether the clinical isolates were F. nucleatum or not, 16S rDNA of them were cloned and sequenced. The sequencing data were used in homology search with database of GenBank. When the homology was above 98% compared with the nucleotide sequence of a certain bacteria, it was judged as the same species with the bacteria. 23 strains of F. nucleatum were isolates from subgingival plaque of periodontitis patient. The clinical isolates of F. nucleatum were classified into 10 groups using phylogenetic analysis of 16S rDNA sequence. F. nucleatum subspecies nucleatum-specific DNA probe Fu4(1.3 kb) reacted with genomic DNAs from 8 type strains of F. nucleatum and it reacted strongly with those from 8 clinical isolates. The Fp4(0.8 kb) reacted with F. nucleatum subsp. polymorphum ATCC 10953 and one clinical isolates. Fv35(1.9 kb) and Fs17(8.2 kb) probes reacted with genomic DNAs from F. nucleatum subsp. vincentii ATCC 49256 and F. nucleatum subsp. fusiform ATCC 51190, respectively. Our results showed that it is not enough to evaluate the specificity of F. nucleatum subspecies-specific DNA probes with only dot blot hybridization. Therefore, Southern blot analysis will be necessary to confirm the specificity of F. nucleatum subspecies-specific DNA probes.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.105-111
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• 2000

본 연구는 Balb/c mice를 이용하여 Porphyromonas gingivalis 381(Pg)로 면역하기 전에 Fusobacterium nucleatum ATCC 10953(Fn)로 면역한 Group 1(N=10)과 Pg 로만 단독 면역을 시행한 Group 2(N=10)로부터 채취한 혈청의 Pg에 대한 식균능력을 비교하는 데 그 목적이 있다. 면역 후 혈청항체는 Pg에 대해 현저히 상승하였으나, 두 그룹간의 평균 항체역가는 통계적으로 차이가 없었다. 식균능력을 비교한 결과, Pg로만 단독 면역한 경우 식균능력이 Fn으로 먼저 면역한 Group 1의 경우보다 현저히 높았으며, 혈청항체역가와 식균지수와는 긴밀한 상관관계를 보였다. 결론적으로 치주세균의 사전 감염은 후속적인 세균감염에 대한 숙주 면역기능(식균능력)에 교란을 가져 올 수 있다.

• Journal of Microbiology
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• v.43 no.4
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• pp.331-336
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• 2005

The objective of this study was to assess the strain-specificity of a DNA probe, Fu12, for Fusobacterium nucleatum subsp. nucleatum ATCC $25586^T$ (F. nucleatum ATCC $25586^T$), and to develop sets of strain-specific polymerase chain reaction (PCR) primers. Strain-specificity was tested against 16 strains of F. nucleatum and 3 strains of distinct Fusobacterium species. Southern blot hybridization revealed that the Fu12 reacted exclusively with the HindIII-digested genomic DNA of F. nucleatum ATCC $25586^T$. The results of PCR revealed that three pairs of PCR primers, based on the nucleotide sequence of Fu12, generated the strain-specific amplicons from F. nucleatum ATCC $25586^T$. These results suggest that the DNA probe Fu12 and the three pairs of PCR primers could be useful in the identification of F. nucleatum ATCC $25586^T$, especially with regard to the determination of the authenticity of the strain.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.130-136
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• 2012

The GroEL heat-shock protein from Fusobacterium nucleatum, a periodontopathogen, activates risk factors for atherosclerosis in human microvascular endothelial cells (HMEC-1) and ApoE-/- mice. In this study, we analyzed the signaling pathways by which F. nucleatum GroEL induces the proinflammatory factors in HMEC-1 cells known to be risk factors associated with the development of atherosclerosis and identified the cellular receptor used by GroEL. The MAPK and NF-${\kappa}B$ signaling pathways were found to be activated by GroEL to induce the expression of interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and tissue factor (TF). These effects were inhibited by a TLR4 knockdown. Our results thus indicate that TLR4 is a key receptor that mediates the interaction of F. nucleatum GroEL with HMEC-1 cells and subsequently induces an inflammatory response via the MAPK and NF-${\kappa}B$ pathways.

• International Journal of Oral Biology
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• v.30 no.2
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• pp.59-63
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• 2005

Postantibiotic effects (PAE) refer to suppression of the bacterial growth following limited periods of exposure to an antibiotic and subsequent to the removal of the antibiotic agent. Fusobacterium nucleatum and Porphyromonas gingivalis are Gram-negative anaerobic bacteria associated with several periodontal diseases. In this study, postantibiotic effects (PAE), postantibiotic sub-MIC effect (PA SME) and sub-MIC effect (SME) of antibiotics on F. nucleatum ATCC 25586 and P. gingivalis W50 were investigated. The PAE was induced by 10X the MIC of antibiotic and antibiotic was eliminated by washing. The PA SMEs were studied by addition of 0.1, 0.2 and 0.3X MICs during the postantibiotic phase of the bacteria, and the SMEs were studied by exposition of the bacteria to antibiotic at the sub-MICs only. Amoxicillin, doxycycline and tetracycline induced PAE for F. nucleatum ATCC 25586 and P. gingivalis W50. But metronidazole and penicillin induced PAE for only F. nucleatum ATCC 25586. Metronidazole and doxycycline induced PA SME and SME for both species of anaerobic bacteria used in this study. The PA SME values for both strains were substantially longer than the SME values. The present study showed the existence of PAE, PA SME and SME for various antibiotics against F. nucleatum ATCC 25586 and P. gingivalis W50.

• International Journal of Oral Biology
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• v.46 no.3
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• pp.127-133
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• 2021

We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.40-48
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• 1999

This study was designed to examine the specificities of the designed primers for F. nucleatum and F. necrophorum and to compare the PCR results using clinical samples with those of the anaerobic culture method. F. nucleatum and F. necrophorum spp. are frequently isolated in infected root canals, and they are related to periapical diseases. F. nucleatum(VPI 10197) and F. necrophorum(ATCC 25286) were used as references for PCR reaction, and thirty five teeth with one canal and periapical lesion were used. The samples were cultured anaerobically and identified using Rapid ID 32A(BioMerieux Vitek, Inc., France) as biochemical battery. In the GenBank database, species-specific PCR primers(nuc1/nuc2 primers for F. nucleatum and nec1/nec2 primers for F. necrophorum) were designed from the 16S ribosomal DNA(rDNA) sequences of F. nucleatum(accession number M58683) and F. necrophorum(accession number AF044948). PCR procedures of F. nucleatum(VPI 10197) and F. necrophorum (ATCC 25286) were simulated on a computer software. Amplify(v.1.2${\beta}$ for Macintosh). 820 bps and 817 bps of nucleotides were expected, respectively. Using extracted DNAs with QiaAmp tissue kit(Qiagen co., Germany), PCR was done. The results were as follows : 1. The nuc1/nuc2 primers produced an amplicon of 820 bps and the nec1/nec2 primers produced an amplicon of 817 bps. 2. The nuc1/nuc2 primers and the nec1/nec2 primers were specific and did not react with species other than the designated ones(i.e. nuc1/nuc2 primers did not produce amplicons for F. necrophorum, and vice versa.). And the PCR products of Porphyromonas endodontalis(ATCC 35406), Porphyromonas gingivalis(ATCC 33277), Prevotella intermedia(ATCC 25611), and Prevotella nigrescens(ATCC 33563), frequently isolated in infected root canals and periapical lesions, were not amplified by the primers specific for Fusobacterium nucleatum and Fusobacterium necrophorum. 3. This method utilizing PCR could detect F. nucleatum and F. necrophorum in clinical samples, while anaerobic culture method could detect neither.

• International Journal of Oral Biology
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• v.49 no.1
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• pp.1-9
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• 2024

Oral bacterial infections substantially affect the development of various periodontal diseases and oral cancers. However, the molecular mechanisms underlying the association between Fusobacterium nucleatum (F. nucleatum ), a major periodontitis (PT)-associated pathogen, and these diseases require extensive research. Previously, our RNA-sequencing analysis identified a few hundred differentially expressed genes in patients with PT and peri-implantitis (PI) than in healthy controls. Thus, in the present study using oral squamous cell carcinoma (OSCC) cells, we aimed to evaluate the effect of F. nucleatum infection on genes that are differentially regulated in patients with PT and PI. Human oral squamous cell carcinoma cell lines OSC-2O, HSC-4, and HN22 were used. These cells were infected with F. nucleatum at a multiplicity of infection of 100 for 3 hours at 37℃ in 5% CO₂. Gene expression was then measured using reverse-transcription polymerase chain reaction. Among 18 genes tested, the expression of CSF3, an inflammation-related cytokine, was increased by F. nucleatum infection. Additionally, F. nucleatum infection increased the phosphorylation of AKT, p38 MAPK, and JNK in OSC-20 cells. Treatment with p38 MAPK (SB202190) and JNK (SP600125) inhibitors reduced the enhanced CSF3 expression induced by F. nucleatum infection. Overall, this study demonstrated that F. nucleatum promotes CSF3 expression in OSCC cells through p38 MAPK and JNK signaling pathways, suggesting that p38 MAPK and JNK inhibitors may help treat F. nucleatum-related periodontal diseases by suppressing CSF3 expression.