• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.343-354
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• 2008

Purpose: Aggregatibacter actinomycetemcomitans is associated with localized aggressive periodontitis. It produces cytolethal distending toxin (CDT), which induces cell cycle arrest in the G2/M phase. The CDT holotoxin is composed of CdtA, CdtB, and CdtC. CdtB has structural homology to human DNase I and is an active component of the CDT complex acting as a DNase. In particular, the pattern homology seen in the CdtB subunit has been associated with specific DNase I residues involved in enzyme catalysis, DNA binding, and metal ion binding. So, to study the functions and regulation of recombinant CdtB, we made up a quantity of functional recombinant CdtB and tested it in relation to the metal ion effect. Materials and Methods: We constructed the pET28a-cdtB plasmid from A. actinomycetemcomitans Y4 by genomic DNA PCR and expressed it in the BL21 (DE3) Escherichia coli system. We obtained the functional recombinant CdtB by the refolding system using the dialysis method and then analyzed the DNase activity and investigated the metal ion effect from plasmid digestion. Results: The recombinant CdtB subunit was expressed as the inclusion bodies. We were able to obtain functional recombinant CdtB subunit using refolding system. We confirmed that our refolded recombinant CdtB had DNase activity and was influenced by the metal ions $Mg^{2+}$ and $Ca^{2+}$. Conclusion: We suggest that the factors influencing recombinant CdtB may contribute to CDT associated diseases, such as periodontitis, endocarditic, meningitis, and osteomyelitis.

• Journal of Korean society of Dental Hygiene
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• v.15 no.4
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• pp.735-741
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• 2015

Objectives: Lentinus edodes is an edible mushroom with a variety of beneficial effects such as antitumor, anti-inflammatory, antioxidant, and immune-modulatory activity. This study was carried out to evaluate the antimicrobial activities of Lentinus edodes extracts against oral-related bacteria. Methods: The antimicrobial activities of this extracts were investigated against S. anginosus, S. sobrinus, S. aureus, S. mutans, S. ratti, S. sanguinis, A. viscosus, A. naeslundii, and A. actinomycetemcomitans by the disc diffusion method, minimum inhibitory concentration (MIC), and growth inhibition. Results: Ethanol extracts had no antimicrobial activities, but acetone extracts showed antimicrobial activities against A. viscosus and A. actinomycetemcomitans and ethyl acetate extracts had effects against S. aureus, S. sanguinis, A. viscosus, and A. actinomycetemcomitans. Conclusions: The inhibitory effect of Lentinus edodes extracts was investigated on the growth of A. viscosus. Ethyl acetate and acetone extracts showed 90% and 77% inhibitory effect, respectively, against A. viscosus for 24 hrs. Ethyl acetate extracts had MIC of 25.0 mg/ml and acetone extracts showed MIC of >25.0 mg/ml.

• Korean journal of food and cookery science
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• v.27 no.1
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• pp.1-9
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• 2011

Anti oralmicrobial effects of Nulembo nucifera were determined against S.mutans, S.sobrinus S.sobrinus, F.nucleatum, and A.actinomycetemcomitans using paper disc method, minimum inhibitory concentrate (MICs). Extracts of lotus leaf showed the highest yield. MeOH extract is 21%, Chloroform fraction is 4.2%, ethylacetate fraction is 8.2%, water fraction is 19%. Different parts such as flower, leaf, seed and pod showed antimicrobial effects against S.mutans, with flower and seed extracts showing strong antimicrobial effect aganinst S.sobrinus KCCM11897. Leaf extract(1000pm concentration) showed over 50% inhibitory effect against S.mutans and S.sobrinus KCCM11897. Flower extract showed over 40% inhibitory effect against F.nucleatum and A.actinomycetemcomitans. MICs of flower extract against S.sobrinus KCCM11897,11898 and leaf extract against S.mutans, S.sobrinus KCCM11897 were $625\;{\mu}g/ml$, indicating Nulembo nucifera extract can exert antimicrobial activity even at low concentration. All extractes with heat at $120^{\circ}C$ had antimicrobial activity, which means that is a very stable substances. F.nucleatum and A.actinomycetemcomitans was stable against acid it had a trend that the more akali side was the lower acitivity.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.202-215
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• 1996

The purpose of this study was to an in estigate the antibiotic susceptibiliity of Actinoobacillus actinomycetemcomitans isolated from the subgingival plaque to adult periodontitis. Seven bacterial strains were tested for their susceptibility to 10 antimicrobial agents under disk diffusion method and broth dilution methold, Seven patients with deep pocket(6mm) were selected for this study. They had not taken antibiotics for 6 months and no history of dental treatment for 6 months and no history of dental treatment for 6 months before this study. The results were as follows : 1. For the antibiotic disk diffusion method, seven A. actinimycetemcomitans were tested with 10 antimicrobial agents which comprised penicillin, gentamycin, clindamycin, lincomycin, ampicillin, erythromycin, tetracycline, amikacin, chloramphenicol, and vancomycin. The sensitive antibiotics were tetracycline, vancomycin, and chloramphenicol and the resistant antibiotics were clindamycin, and lincomycin. The other antimicrobial agents were less active. 2. From the study of determination on the minimal inhibitory concentration(MIC) by broth dilution method, the MIC of tetracycline to seven strains of the A. actinomycetemcomitans was $0.5-1.0{\mu}g/ml$, that of clindamycin was $32{\mu}g/ml$. These data suggest that tetracycline may be valuable drugs in the elimination of A. actinimycetemcomitans from the patients with adult periodontitis

• International Journal of Oral Biology
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• v.39 no.1
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• pp.15-22
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• 2014

Aggregatibacter actinomycetemcomitans is an important pathogen in the development of localized aggressive periodontitis. Lipopolysaccharide (LPS) is a virulent factor of periodontal pathogens that contributes to alveolar bone loss and connective tissue degradation in periodontal disease. Our present study was designed to investigate the cytokine expression and signaling pathways regulated by A. actinomycetemcomitans LPS (Aa LPS). Cytokine gene expression profiling in RAW 264.7 cells was performed by microarray analyses. The cytokine mRNA and protein levels and related signaling pathways induced by Aa LPS were measured by RT-PCR, ELISA and western blotting. Microarray results showed that Aa LPS strongly induced the expression of NF-${\kappa}B$, NF-${\kappa}B$-related genes, inflammatory cytokines, TNF-${\alpha}$ and IL-$1{\beta}$ in RAW 264.7 cells. NF-${\kappa}B$ inhibitor pretreatment significantly reduced the levels of TNF-${\alpha}$ and IL-$1{\beta}$ mRNA and protein. In addition, the Aa LPS-induced TNF-${\alpha}$ and IL-$1{\beta}$ expression was inhibited by p38/JNK MAP kinase inhibitor pretreatment. These results show that Aa LPS stimulates TNF-${\alpha}$ and IL-$1{\beta}$ expression through NF-${\kappa}B$ and p38/JNK activation in RAW 264.7 cells, suggesting the essential role of this pathway in the pathogenesis of localized aggressive periodontitis.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.679-693
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• 1995

The present study has been performed to see the intrafamilial transmission of periodontopathic organism Actinobacillus actinomycetemcomitans in Koreans having various froms of periodontal diseases. 17 clinical isolates from 8 periodontal patients and 20m clinical isolates from their 8 family members were grown anaerobically for the serotyping and the extraction of genomic DNA. The DNA was digested with restriction endonucleases (EcoRI+HindIII) and plasmid pAA 2097(kindly provided by Dr. DiRienzo, Univ. of Pennsylvania) including 4.7kb-size randlomly clone probe for restriction length pleomorphism analysis(RFLP). RFLP patterns of reference serotypes a, b, c, d, and e were used as the genotypes A, B, C, D, and E, respectively for comparison of genotypes of clinical isolates. 28 out of total 37 clinical isoltes belonged to either one of 5 basic gentotypes and 9 remaining isolats did not fall into any types, and hence were designate as non-type(NT). Genotype C were the most frequently found one(35.1%) and genotype B has not isolated. Intrafamilial transmission of bacteria between spouses, brothers and sisters, and parents and their offsprings, resepctively could well be demonstrated by comparing RFLP patterns. There were not any specific genotypes which showed predominance over others in terms of transmission.

• Journal of Periodontal and Implant Science
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• v.45 no.5
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• pp.178-183
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• 2015

Purpose: Elderly people are thought to be more susceptible to periodontal disease due to reduced immune function associated with aging. However, little information is available on the nature of immune responses against putative periodontal pathogens in geriatric patients. The purpose of this study was to evaluate the serum IgG antibody responses to six periodontal pathogens in geriatric subjects. Methods: The study population consisted of 85 geriatric patients and was divided into three groups: 29 mild (MCP), 27 moderate (MoCP), and 29 severe (SCP) chronic periodontitis patients. Serum levels of IgG antibody to Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia were measured by enzyme-linked immunosorbent assay (ELISA) and compared among the groups. Results: All three groups showed levels of serum IgG in response to P. gingivalis, A. actinomycetemcomitans, and P. intermedia that were three to four times higher than levels of IgG to T. forsythia, T. denticola, and F. nucleatum. There were no significant differences among all three groups in IgG response to P. gingivalis (P=0.065), T. forsythia (P=0.057), T. denticola (P=0.1), and P. intermedia (P=0.167), although the IgG levels tended to be higher in patients with SCP than in those with MCP or MoCP (with the exception of those for P. intermedia). In contrast, there were significant differences among the groups in IgG levels in response to F. nucleatum (P=0.001) and A. actinomycetemcomitans (P=0.003). IgG levels to A. actinomycetemcomitans were higher in patients with MCP than in those with MoCP or SCP. Conclusions: When IgG levels were compared among three periodontal disease groups, only IgG levels to F. nucleatum significantly increased with the severity of disease. On the contrary, IgG levels to A. actinomycetemcomitans decreased significantly in patients with SCP compared to those with MCP. There were no significant differences in the IgG levels for P. gingivalis, T. forsythia, T. denticola, and P. intermedia among geriatric patients with chronic periodontitis.

• Journal of Korean society of Dental Hygiene
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• v.20 no.3
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• pp.387-397
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• 2020

Objectives: This study aimed to evaluate the inhibitory effects of probiotics containing Lactobacillus reuteri on Streptococcus mutans and Aggregatibacter actinomycetemcomitans. In addition, the degree of biofilm formation, initial acidity, buffering ability, and acid production performance were measured to confirm the dental caries-inducing ability. Methods: S. mutans (KCTC3065) and A. actinomycetemcomitans (KCTC2581) were used as experimental strains. The number of viable cells, degree of biofilm formation, initial pH, buffering capacity, and production performance were measured for comparing L. reuteri-containing probiotics and Bulgaris. Results: The viability of S. mutans in the groups was reduced in the following order: Bulgaris, probiotics, control. The degree of biofilm formation was significantly higher at 0% and gradually reduced at different concentrations (p<0.01). At 2.5%, the absorbance of the probiotics and Bulgaris groups differed significantly (p<0.01). The acid formation ability differed significantly based on the performance of S. mutans in each product (p<0.05). The absorbance of the probiotics group was significantly lower than that of the Bulgaris group (p<0.01). Conclusions: This study suggests that the use of L. reuteri-containing probiotics as an adjuvant for the prevention and decreasing of oral diseases may reduce their incidence, which can be considered one of the benefits of using probiotics.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.541-560
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• 1994

The present study was performed to evaluate the relationship between the serotype or the genotype of Actnobacillus actinomycetemcomitans (A. a.) and the severity of periodontal disease. Total 64 A. a. clinical isolates were sampled from 46 sites of 20 subjects classified into the group I (1 periodontally healthy subject, 2 gingivitis patients, 5 ealry adult periodontitis patients), group II (3 moderatelly adult periodontitis patients) and group III (1 advanced adult periodontitis patient, 8 RPP patients). Southern bolt hybridization (fingerprinting) patterns of the five reference strains, A. a. strain ATCC 29523 (serotype a), ATCC 29522 (Serotype b), ATCC 43719 (serotype c), IDH 781 (serotype d) and IDH 1705 (serotype e), were used as the five basic genotypic patterns (A, B, C, D, E). NT type was designated as one which did dnot represent any of those five basic types. The serotypes were determined by ELISA technique with the serum samples from pre-immunized rabbit. Based on subject-based analysis, it was noted that genotypes A and C, NT, and B, D, E were significantly related to the disease groups I, II, and III, respectively. It was also noted that both the serotypes a and c were significantly related to the disease group I and II, while serotypes were significantly related bm), and serotypes b and nd were frequently found in sites with severe attachment loss (LA>6mm). The results indicated that the significant relationship can be delineated beteen the genotypes and the serotypes of Acinobacillus actinomycetemcomitans and the periodontal disease severity. The results also indicated that genotyping can provide more detailed information on its relationship with the disease severity based on both the patient-based and the site-based analyses.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.153-166
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• 1995

54 clinical isolates of Actinobacillus actinomycetemcomitans showed distinct hybrdization patern(DAN fingerprinting patterns) when the bacterial DNA were hybridized with randomly cloned 4.7 - kb DNA probe. The frequency of the genotypic distribution demonstrated that type C was the most prevalent genotype, the next being D, NT, A, B, and E in the descending order. The most prevalent serotype was serotype c, the next being a, nd, and b in the descending order. It was noted that the one serotype can represent more than two different genotypes and that multiple genotypic variants can also exist in the periodontal pockets within the sam subject.