• International Journal of Oral Biology
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• 제46권4호
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• pp.155-159
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• 2021

This study aimed to develop strain-specific polymerase chain reaction (PCR) primers to detect Fusobacterium hwasookii KCOM 1249^T, F. hwasookii KCOM 1253, F. hwasookii KCOM 1256, F. hwasookii KCOM 1258, and F. hwasookii KCOM 1268 on the basis of nucleotide sequences of a gene specific to each strain. The unique genes for each F. hwasookii strain were determined on the basis of their genome sequences using Roary. The strain-specific PCR primers based on each strain-specific gene were designed using PrimerSelect. The specificity of each PCR primer was determined using the genomic DNA of the 5 F. hwasookii strains and 25 strains of oral bacterial species. The detection limit and sensitivity of each strain-specific PCR primer pair were determined using the genomic DNA of each target strain. The results showed that the strain-specific PCR primers correspond to F. hwasookii KCOM 1249^T, F. hwasookii KCOM 1253, F. hwasookii KCOM 1258, F. hwasookii KCOM 1256/F. nucleatum subsp. polymorphum KCOM 1260, or F. hwasookii KCOM 1268/Fusobacterium sp. oral taxon 203 were developed. The detection limits of these strain-specific PCR primers ranged from 0.2 to 2 ng of genomic DNA for each target strain. The results suggest that these strain-specific PCR primers are valuable in quality control for detecting specific F. hwasookii strains.

• International Journal of Oral Biology
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• 제43권4호
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• pp.217-222
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• 2018

Phagocytosis is a fundamental process in which phagocytes capture and ingest foreign particles including pathogenic bacteria. Several oral pathogens have anti-phagocytic strategies, which allow them to escape from and survive in phagocytes. Impaired bacteria phagocytosis increases inflammation and contributes to inflammatory diseases. The purpose of this study is to investigate the influences of various agents on oral pathogenic phagocytosis. To determine phagocytosis, Streptococcus mutans, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), and was measured using flowcytometery and confocal microscopy. The influencing factors on phagocytosis were evaluated through the pretreatment of ROS inhibitor (N-acetyl-L-cysteine (NAC)), lysozyme, potassium chloride (KCI) and adenosine triphosphate (ATP) in THP-1 cells. Expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). The phagocytosis of various bacteria increased in a MOI-dependent manner. Among the tested bacteria, phagocytosis of P. gingivalis showed the highest fluorescent intensity at same infection time. Among the tested inhibitors, the NAC treatment significantly inhibited phagocytosis in all tested bacteria. In addition, NAC treatment indicated a similar pattern under the confocal microscopy. Moreover, NAC treatment significantly increased the bacteria-induced secretion of $IL-1{\beta}$ among the tested inhibitors. Taken together, we conclude that the phagocytosis occurs differently depending on each bacterium. Down-regulation by ROS production inhibited phagocytosis and lead increased of oral pathogens-associated inflammation.

• 치위생과학회지
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• 제19권4호
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• pp.213-219
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• 2019

Background: Smoking exerts an adverse effect on the periodontal tissue by reorganizing the ecosystem of oral microorganisms and is considered to be an important factor in the development of periodontal disease. Although cross-sectional studies on smokers and non-smokers have been attempted to investigate the microbial differences in periodontal oral cavity, only few studies have been conducted to investigate the changes in oral microorganisms during smoking cessation. The purpose of this study was to investigate the changes of bacteria in saliva and gingival crevicular fluid (GCF) over a period of one year among 11 smokers trying to quit smoking. Methods: Eleven smokers trying to quit smoking visited the clinic at baseline, two weeks, two months, four months, six months, and 12 months to give saliva and GCF samples. The amounts of 16S rRNA, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum subsp. nucleatum, Streptococcus mutans, and Streptococcus sobrinus in saliva and GCF were quantified using real-time polymerase chain reaction TaqMan probe assay. The results were analyzed by nonparametric statistical analysis using Friedman test and Spearman correlation coefficient. Results: After cessation of smoking, the amounts of 16S rRNA corresponding to P. gingivalis, F. nucleatum, P. intermedia, and T. denticola in saliva decreased and then again increased significantly. The amount of F. nucleatum 16S rRNA in GCF decreased significantly after smoking cessation. Positive correlations were observed between 16S rRNA and F. nucleatum and between F. nucleatum and T. denticola in saliva and GCF. Conclusion: Even if the number of subjects in this study was small, we suggest that smoking cessation may reduce the total bacterial amount and F. nucleatum in GCF. However, the results regarding changes in the microbial ecosystem due to smoking or smoking cessation were inconsistent. Therefore, further in-depth studies need to be carried out.

• 한국융합학회논문지
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• 제13권5호
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• pp.97-102
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• 2022

본 연구에서는 누에 추출물과 여주 추출물이 S. mutans와 F. nucleatum에 미치는 항균효과를 알아보고자 하였다. BHI 액체배지에 S. mutans 또는 F. nucleatum과 0%, 2%, 4%, 8% 농도의 누에가루 또는 여주가루 추출물을 첨가하여 배양한 뒤 광학밀도 600nm에서 시료를 측정하였다, 그 결과 S. mutans의 흡광도는 누에 추출물에서는 8%에서만 유의적으로 흡광도의 수치가 감소하였고 여주 추출물에서는 모든 농도에서 유의적으로 흡광도의 수치가 감소하였다. F. nucleatum의 흡광도는 누에 추출물과 여주 추출물에 모두 농도 의존적으로 유의적으로 감소하였다. 이는 누에 추출물과 여주 추출물이 구강질병의 예방 및 치료들 위한 소재로 사용 할 수 있는 가능성을 시사한다.

• International Journal of Oral Biology
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• 제39권1호
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• pp.35-40
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• 2014

Halitosis is caused by consumption of certain foods or drinks and production of volatile sulfur compounds (VSCs) by periodontopathogens. VSCs-related halitosis is not easily removed using mechanical or chemical therapies such as dental floss, plaque control and mouth rinse. Lactobacillus are known to be probiotics and stimulate immune systems of human. Furthermore, L. casei ATCC 334 and L. rhamnosus GG have an effect on protection of dental caries in vitro studies. The aim of this study was to investigate effect of Lactobacillus on halitosis by Fusobacterium nucleatum- and Porphyromonas gingivalis-producing VSCs and to analyze inhibitory mechanism. The periodontopathogens were cultivated in the presence or the absence Lactobacillus, and the level of VSCs was measured by gas chromatograph. For analysis of inhibitory mechanisms, the susceptibility assay of the spent culture medium of Lactobacillus against F. nucleatum and P. gingivalis was investigated. Also, the spent culture medium of Lactobacillus and periodontopathogens were mixed, and the emission of VSCs from the spent culture medium was measured by gas chromatograph. L. casei and L. rhamnosus significantly reduced production of VSCs. L. casei and L. rhamnosus exhibited strong antibacterial activity against F. nucleatum and P. gingivalis. The spent culture medium of L. casei inhibited to emit gaseous hydrogen sulfide, methyl mercaptan and dimethyl sulfide from the spent culture medium of periodontopathogens. However, the spent medium of L. rhamnosus repressed only dimethyl sulfide. L. casei ATCC 334 may improve halitosis by growth inhibition of periodontopathogens and reduction of VSCs emission.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.607-607
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• 2003

The purpose of this presentation is to investigate whether the certain therapy resistant bacteria can impair the immune defense system in the pariapical tissue. Recent studies have reported that the facultative or obligatory anaerobic bacteria such as Fusobacterium nucleatum, Enterococcus faecalis and Actinomyces species and Gram positive facultative bacteria Enterococcus faecalis have been shown to dominate in persistent periapical lesion and usually recovered from failed root canal treated cases. Moreover, E. faecalis has been reported to withstand the antimicrobial agent and endure potential starvation and resist the antibacterial effect of calcium hydroxide intracanal medication.(omitted)

• 대한소아치과학회지
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• 제39권4호
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• pp.366-372
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• 2012

본 연구의 목적은 현재 많이 사용되고 있는 ProRoot MTA (Dentsply Tulsa, USA)와 최근 국내에서 새로 개발된 OrthoMTA (Bio MTA, Korea)의 감염된 근관에서 주로 발견되는 3개의 미생물에 대한 효과를 다양한 농도와 시간에서 비교하는 것이다. 50, 25, 12.5 mg/mL의 농도로 준비된 ProRoot MTA와 OrthoMTA에 Enterococcus faecalis, Fusobacterium nucleatum 그리고 Staphylococcus epidermidis를 접종 후 24, 48, 72시간에 항미생물 효과를 관찰하여 다음과 같은 연구결과를 얻었다. E. faecalis의 경우 ProRoot MTA와 OrthoMTA 50, 25, 12.5 mg/mL 농도의 모든 시간대에서 세균을 완전히 억제하지는 못했지만 양성 대조군에 비해 성장이 조금 감소한 양상을 보였다(p < 0.05). F. nucleatum의 경우 ProRoot MTA 50 mg/mL 농도의 24시간에서 미생물을 억제하였으나 시간이 지남에 따라 세균의 성장을 보인 반면 OrthoMTA의 경우 같은 농도에서 시간이 지나도 계속 세균을 억제하였다(p < 0.05). S. epidermidis의 경우 ProRoot MTA 50 mg/mL, OrthoMTA 50, 25 mg/mL 농도의 24시간에서 억제 효과를 보였으나 시간이 지나면서 세균이 조금씩 성장하였다. 그러나 전체적으로 모든 농도와 시간에서 양성 대조군에 비해서는 억제 효과를 나타냈다(p < 0.05). 본 연구를 통해 국내에서 새로 개발된 OrthoMTA는 기존의 ProRoot MTA보다 항균활성을 가지고 있음을 알 수 있었다.

• International Journal of Oral Biology
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• 제37권2호
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• pp.69-75
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• 2012

Although neutrophils function in both defense and tissue destruction, their defensive roles have rarely been studied in association with periodontitis. We hypothesized that peripheral neutrophils are pre-activated in vivo in periodontitis and that hyperactive neutrophils would show enhanced phagocytic ability as well as an increased production of reactive oxygen species (ROS). Peripheral blood neutrophils from patients with aggressive periodontitis and age/gender-matched healthy subjects (10 pairs) were isolated. The levels of CD11b and CD64 expression on the neutrophils and the level of plasma endotoxin were determined by flow cytometry and a limulus amebocyte lysate test, respectively. In addition, neutrophils were subjected to a flow cytometric phagocytosis assay and luminol-enhanced chemiluminescence for non-opsonized Fusobacterium nucleatum in parallel. The neutrophilsfrom most patients expressed increased levels of both CD11b and CD64. In addition, the plasma from these patients tended to contain a higher level of endotoxin than the healthy controls. In contrast, no differences were found between the two groups with regard to phagocytosis or ROS generation by F. nucleatum. The ability to phagocytose F. nucleatum was found to positively correlate with the ability to produce ROS. In conclusion, peripheral neutrophils from patients with aggressive periodontitis are hyperactive but not hyperreactive to F. nucleatum.

• 생약학회지
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• 제47권1호
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• pp.43-48
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• 2016

The aim of the study was performed to examine the anticariogenic potential of purified bee venom (Apis mellifera L., PBV) collected using bee venom collector from cariogenic bacteria, Streptococcus mutans, Streptococcus sanguis, Porphyromonas gingivalis, and Fusobacterium nucleatum. The anticariogenic effect of purified bee venom was evaluated by agar well diffusion method, minimum inhibitory concentraion (MIC), minimum bactericidal concentration (MBC), and postantibiotic effect (PAE). The human lower gingiva epithelial cell cytotoxicity of purified bee venom was also evaluated. Purified bee venom exhibited significant inhibition of bacterial growth of S. mutans, S. sanguis, P. gingivalis, and F. nucleatum with MIC value of 0.68, 0.85, 3.49, and $2.79{\mu}g/ml$, respectively. The MBC value of purified bee venom against S. mutans, S. sanguis, P. gingivalis, and F. nucleatum was 1.34, 1.67, 8.5, and $6.8{\mu}g/ml$. Furthermore, the results of PAE values against S. mutans, S. sanguis, P. gingivalis, and F. nucleatum showed the bacterial effect with 3.3, 3.45, 2.0, and 2.0. The concentration below 1 mg/ml of purified bee venom had no cytotoxicity in the human lower gingiva epithelial cell. These results suggested that purified bee venom have great potenial as anticariogenic agents.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.401-411
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• 2005

The aim of this study was to determine the minimal inhibitory concentration(MIC) of cefixime, which is a 3rd generation of cefalosporin, against 6 species of putative periodontopathogens; Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythia and Porphyromonas gingivalis. The efficacy of cefixime was examined by comparing it with that of several antibiotics(amoxicillin, $Augmentin^{(R)}$ ciprofloxacin, metronidazole, and tetracycline), which were used as the control. The MIC was measured using a microdilution method. The MIC of cefixime against the putative periodotopathogens, as a single use regimen, was relatively lower than that of the other antibiotics. The MIC of cefixime/metronidazole against P. intermedia ChDC KB14, P. nigrescens ChDC KB50, F. nucleatum ChDC PV-F37, F. nucleatum ChDC F130, and F. nucleatum ChDC F175, as a simultaneous regimen, was lower than that of the other antibiotics. The concentration of cefixime in the crevicular fluid of volunteers who received 250mg every 12 hours for 3 days was $9{\mu}g/ml$ after 9 hours. In conclusion, cefixime showed good antimicrobial activity in a single treatment or as a combined therapy with amoxicillin, $Augmentin^{(R)}$ or metronidazole against 6 periodontopathogens.