• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.907-919
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• 2005

Porphyromonas gingivalis is a gram negative. black-pigmented anaerobe, associated with periodontitis & peri-implantitis. Fimbriae(fimA) of P. gingivalis are filamentous components on the cell surface and important in the colonization and invasion of periodontal tissue. But all P. gnigivalis strains don't have equal pathogenicity, inequality among strains originates from different fimA genotype. P. gnigivalis fimA gene encoding fimbrillin(structural subunit of fimbriae) has been classified into 5 genotypes(types I to V) based on the nucleotide sequences. In the present study, we examined the prevalence of these fimA genotypes in patients with dental implant and the relationship between prevalence of these genotypes and a condition of peri-implant tissue. Dental plaque specimens obtained from 189 peri-implant sulci of 97 patients with dental implants were analyzed by 16S rRNA fimA gene-directed PCR assay. P. gingivalis were detected in 86.2% of the alll samples. Among the P. gingivalis-positive samples, a significant difference in the occurrence of typeII was observed between test and the two control groups. In two control groups, typeII fimA were detected in 6.3%(PD<5mm/BOP-). 18.7%(PD<5mm/BOP+). In the test $group(PD{\geqq}5mm/BOP+)$, type II fimA genotype were detected most frequently in 50.0% . And a correlation between specific fimA types and peri-implantitis was found in $typeII(R^2=l.105)$. These results suggest that P. gingivalis strains that possess typeII fimA are gradually increased, as a condition of peri-implant tissue is getting complicated and are closely associated with peri-implant health status. We speculate that these organisms be involved in peri-implantitis

• 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.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.286-289
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• 2005

Active antibacterial compound against periodontitis-causing bacterium Porphyromonas gingivalis was isolated from Kaempferia pandurata and identified as panduratin A. Minimum inhibitory concentration (MIC) value of panduratin A was $4\;{\mu}g/mL$, much lower than those of other natural antibacterial agents. Panduratin A also showed antibacterial activity against Prevotella intermedia ($2\;{\mu}g/mL$), P. loescheii ($4\;{\mu}g/mL$), and cariogenic Streptococcus mutans ($4\;{\mu}g/mL$). Damage on cell wall and perturbation of cytoplasmic membrane of panduratin A-treated P. gingivalis were visualized through transmission electron microscopy. These results suggest panduratin A, exhibiting strong and preferential antiperiodontal and anticariogenic activities, may be utilized in functional foods for prevention of oral diseases.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.661-668
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• 2001

Anti-P. gingivalis immune sera were obtained from mice immunized with either P. gingivalis alone, or F. nucleaturm followed by P. gingivalis. Two groups of immune sera were examined for binding capacity to P. gingivalis biofilm by confocal laser scanning microscope, Antibody avidity index was also determined for each immune sera. The results indicated that prior immunization of mice with F. nucleaturm impaired P. gingivalis-specific immune sera in binding capacity to biofilm and antibody avidity to P. gingivalis. Elevated antibody responses in patients with destructive periodontal disease has often been related to suboptimal level of protective antibody $(opsonophagocytosis)^{1-3)}$ while post-immune sera obtained with experimental animals using a single periodontal pathogen demonstrated satisfactory levels of protective function against the homologous bacterial $challenge^{4,5)}$.The reason is unclear why elevated IgG responses in periodontal patients to periodontal pathogens do not necessarily reflect their protective function. Such an immune deviation might be derived from the fact that destructive periodontal disease is cumulative result of immunopathologic processes responding to an array of different colonizing microorganisms sequentially infecting in the subgingival environmental niche. Fusobacterium nucleaturm is one of the key pathogens in gingivitis, in the transitional phase of conversion of gingivitis into destructive periodontitk, and in adult $periodontitis^{6-8)}$. It also plays a central role in coaggregation with other important microbial species in subgingival $area^{6,9,10)}$ as well as in $biofilm^{11)}$, especially with Porphyromonas gingjvalis in synergism of virulence in human periodontal disease or in animal $models^{12-14)}$. This organism has also been reported to have immune modulating activity for secondary immune response to Actinobacillus $actinomycetemcomitans^{15)}$. It is presumed that sequential colonization and intermicrobial coaggregation between intermediate and late colonizers could potentially modulate the immune responses and development of specific T cell phenotypes in periodontal lesions. We have recently demonstrated the skewed polarization of P. gingivalis-specific helper T cell clones in mice immunized with F. nucleaturm followed by P. $gingivalis.^{16)}$. Consequently F. nucleaturm may initially prime the immune cells and modify their responses to the successive organism, P. gingivalis. This could explain why one frequently observes non-protective serum antibodies to P. gingivalis in periodontal patients in contrast with those obtained from animals that were immunized with $P.gingivalis\;alone^{17)}$. The present study was performed to investigate the immune modulating effect of F. nucleatum on serum binding to experimental biofilms and the avidity of anti-P. gingivalis antibody.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.565-578
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• 2008

Purpose: Porphyromonas gingivalis(P. gingivalis) heat shock protein (HSP)60 may play a role in the immunopathogenesis of periodontitis as well as atherosclerosis by modulating autoimmune reaction due to its high level of sequence homology between bacteria and human counterpart. The purpose of this study was to identify immunodomiant epitope of P. gingivalis HSP60 that is reactive exclusively to the homologous bacteria without reacting with human HSP. Materials and methods: The present study was performed to identify the peptide specifically recognized by anti-P. gingivalis HSP60 monoclonal antibodies mono-reactive to P. gingivalis HSP60. Results: Four different hybridomas were cloned producing monoclonal IgG antibodies exclusively to P. gingivalis HSP60. Thirty seven synthetic peptides (20-mer with 5-amino acid overlapping) were synthesized. All of these peptide were subject to SDS-PAGE for immunblot analysis. One peptide (TVPGGGTTYIRAIAALEGLK) and the other peptide (TLVVNRLRGSLKICAVKAPG) were recognized by all and one of the four monoclonal antibodies, respectively, that reacted solely with P. gingivalis HSP60. Immunohistochemistry to identify the localization of the HSP60 in the diseased gingival tissues revealed that all of the four monoclonal antibodies were highly reacted with the diseased gingival tissue than normal gingival tissue. Conclusion: The P. gingivalis HSP60 peptides (TVPGGGTTYIRAIAALEGLK and TLVVNRLRGSLKICAVKAPG, respectively) are positively involved in the immunopathologic process of periodontal disease. The peptide may potentially be developed as vaccine candidates. Further investigations are under way to identify more clones producing monoclonal antibodies reactive to P. gingivalis HSP and to other periodontopathogenic bacteria as well, while maintaining specificities to human counterpart.

• 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.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.515-524
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• 1997

헤민과 메나디온 제한에 의한 Porphyromonas gingivalis(P. gingivalis) W50의 병독력의 변화를 검색하고자, 실험관내 병독력을 NIH 3T3 세포의 세포활성 변화로 관찰하였고, 생체내 병독력은 배양상청액을 ICR mouse 피하조직에 주사한 후의 염증반응을 관찰하였다. 헤민 존재 하에 배양한 P. gingivalis W50 배양상청액에 의한 mouse 3T3 세포의 세포활성은 헤민과 메나디온 없이 배양한 세포의 활성보다 낮았다. 헤민과 메나디온을 첨가하지 않고 배양한 세균의 생체내 병독력은 중등도의 염증세포 침윤과 울혈에 의한 출혈, 미약한 세포간질의 부종과 근육 파괴를 보였다. 메나디온 존재 하에서 배양한 세균은 미약한 염증세포의 침윤, 울혈에 의한 출혈 및 근육의 파괴가 관찰되었다. 헤민 존재하에서 중등도의 울혈에 의한 출혈, 미약한 세포간질의 부종, 염증세포의 침윤 및 근육파괴가 관찰되었다. 헤민과 메나디온 존재 하에서 배양한 세균은 심한 염증세포의 침윤과 중등도의 세포간질의 부종 및 울혈에 의한 출혈을 보였다. 이상의 연구 결과 P. gingivalis W50 배양 상층액의 병독력은 헤민에 의하여 영향을 받는 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.675-687
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• 2000

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. gingi - valis). 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.

• Journal of Periodontal and Implant Science
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• v.48 no.1
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• pp.60-68
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• 2018

Purpose: The aim of this study was to evaluate the ability of Porphyromonas gingivalis (P. gingivalis) to induce oxidation of high-density lipoprotein (HDL) and to determine whether the oxidized HDL induced by P. gingivalis exhibited altered antiatherogenic function or became proatherogenic. Methods: P. gingivalis and THP-1 monocytes were cultured, and the extent of HDL oxidation induced by P. gingivalis was evaluated by a thiobarbituric acid-reactive substances (TBARS) assay. To evaluate the altered antiatherogenic and proatherogenic properties of P. gingivalistreated HDL, lipid oxidation was quantified by the TBARS assay, and tumor necrosis factor alpha (TNF-${\alpha}$) levels and the gelatinolytic activity of matrix metalloproteinase (MMP)-9 were also measured. After incubating macrophages with HDL and P. gingivalis, Oil Red O staining was performed to examine foam cells. Results: P. gingivalis induced HDL oxidation. The HDL treated by P. gingivalis did not reduce lipid oxidation and may have enhanced the formation of MMP-9 and TNF-${\alpha}$. P. gingivalistreated macrophages exhibited more lipid aggregates than untreated macrophages. Conclusions: P. gingivalis induced HDL oxidation, impairing the atheroprotective function of HDL and making it proatherogenic by eliciting a proinflammatory response through its interaction with monocytes/macrophages.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.705-709
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• 2021

Porphyromonas gingivalis (P. gingivalis) is a major bacterial pathogen that causes periodontitis, a chronic inflammatory disease of tissues around the teeth. Periodontitis is known to be related to other diseases, such as oral cancer, Alzheimer's disease, and rheumatism. Thus, a precise and sensitive test to detect P. gingivalis is necessary for the early diagnosis of periodontitis. The objective of this study was to optimize a rapid visual detection system for P. gingivalis. First, we performed a visual membrane immunoassay using 3,3',5,5'-tetramethylbenzidine (TMB; blue) and coating and detection antibodies that could bind to the host laboratory strain, ATCC 33277. Antibodies against the P. gingivalis surface adhesion molecules RgpB (arginine proteinase) and Kgp (lysine proteinase) were determined to be the most specific coating and detection antibodies, respectively. Using these two selected antibodies, the streptavidin-horseradish peroxidase (HRP) reaction was performed using a nitrocellulose membrane and visualized with a detection range of 10³-10⁵ bacterial cells/ml following incubation for 15 min. These selected conditions were applied to test other oral bacteria, and the results showed that P. gingivalis could be detected without cross-reactivity to other bacteria, including Streptococcus mutans and Escherichia fergusonii. Furthermore, three clinical strains of P. gingivalis, KCOM 2880, KCOM 2803, and KCOM 3190, were also recognized using this optimized enzyme immunoassay (EIA) system. To conclude, we established optimized conditions for P. gingivalis detection with specificity, accuracy, and sensitivity. These results could be utilized to manufacture economical and rapid detection kits for P. gingivalis.