• 동의생리병리학회지
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• 제17권2호
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• pp.574-579
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• 2003

Methicillin-resistant Staphylococcus aureus (MRSA) has been emerging worldwide as one of the most important hospital and community pathogens. Therefore, new agents are needed to treat the MRSA. In the present study, we investigated antimicrobial activity of ethyl acetate, methanol, and water extracts of Curcuma longa L. (C. longa) aganist clinical isolates of MRSA. The ethyl acetate extract of C. long a demonstrated a higher antibacterial activity than the methanol extract or water extract. Since the ethyl acetate extract was more active than other extracts, we examined whether ethyl acetate extract may restore the antibacterial activity of β-lactams and alter the adhesion and invasion of MRSA to human mucosal fibroblasts (HMFs). In the checkerboard test, ethyl acetate extract of C. longa markedly lowered the MICs of ampicillin and oxacillin against MRSA. In the bacterial adhesion and invasion assay, MRSA intracellular invasion were notably decreased in the presence of 0.125 - 2 mg/ml of C. longa extract compared to the control group. These results suggest that ethyl acetate extract of C. longa may have antibacterial activity and the potential to restore the effectiveness of β-lactams against MRSA, and inhibit the MRSA adhesion and invasion to HMFs.

• 대한치과교정학회지
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• 제39권2호
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• pp.105-111
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• 2009

법랑질 탈회는 교정 치료 중에 발생하는 대표적인 부작용으로서 특히 교정용 브라켓에 대한 세균 부착이 그 원인이 될 수 있다. 본 연구의 목적은 서로 다른 표면 특성을 가진 세 종류의 브라켓을 구강 내 장착했을 때 각 재료의 표면에 대한 mutans streptococci 부착 정도를 측정하여 브라켓 재료에 따른 법랑질 탈회 및 치아 우식 발생 가능성을 분석하는 것이었다. 상하악 및 치아 부위별 mutans streptococci 부착 정도의 차이를 배제하고 브라켓 원재료에 따른 차이만을 검출하기 위하여 균형완전블록 실험계획을 설계하였다. 피실험자인 30세 여성의 구강 내에 장착할 수 있는 tooth positioner 형태로 3세트의 플라스틱 맞춤 트레이를 제작하였으며, 이 트레이에 직육면체의 형태($4{\times}3{\times}2\;mm$)로 제작한 stainless steel, monocrystalline sapphire, polycrystalline alumina 조각을 세트마다 서로 다른 순서로 전치부와 구치부 순면에 부착하였다 이렇게 제작된 3종류의 실험장치를 12시간 동안 피 실험자의 구강 내에 장착한 후, 각 브라켓 재료 표면에 형성된 치태를 채취하여 bacitracin이 포함된 mitis salivarius배지에서 48시간 배양 후 colony counting을 통해 그 표면에 부착된 mutans streptococci 양을 비교하였다. 이와 같은 방법으로 3세트의 실험장치에 대해서 각각 5회씩 총 15회의 실험을 시행하였다. 그 결과 상하악 및 치아 부위별 및 브라켓 재료별 세균 부착 정도는 모두 유의한 차이를 보이지 않았다. 결론적으로 본 연구의 결과 in vivo condition에서 브라켓 재료의 차이는 mutans streptococci 부착에 영향을 미치지 못하는 것으로 보였다.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.639-644
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• 2008

Purpose: The aim of this study was to compare the number of live and dead bacteria attached to, or within, the stratified squamous epithelium lining the tissue side of the gingival sulcus. Materials and Methods: A total of 50 patients was examined and classified into healthy or diseased sites according to inflammatory status of the gingival tissue. The surface of stratified squamous epithelium was removed by gentle scraping of the gingival sulcus with curettes. The cells were processed in the laboratory by density-gradient centrifugation to separate the epithelial cells from the loose bacteria and debris. The LIVE/$DEAD^{(R)}$ $BacLight^{TM}$ Bacterial Viability Kit was applied and the specimens were observed by an epifluorescent microscope and the number of bacteria was counted. Results: Live and dead bacteria were stained to green and red, irrespectively. Generally, the number of total bacteria in the diseased sites was significantly higher than in the healthy sites. The mean number of detected bacteria in the diseased sites was $58.6{\pm}36.0$ (red bacteria $10.4{\pm}9.2$ / green bacteria $48.2{\pm}30.5$), while it was $1.5{\pm}1.7$ in the healthy sites (red bacteria $0.1{\pm}0.3$ / green bacteria $1.4{\pm}1.5$). The percentage of red bacteria was $17.5{\pm}11.2%$ in the diseased sites and $2.0{\pm}5.8%$ in the healthy sites. Conclusion: The total number of bacteria in the diseased sites was significantly higher than that of the healthy sites. The ratio and the number of red bacteria were also significantly higher in the diseased sites.

• 대한소아치과학회지
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• 제29권4호
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• pp.618-624
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• 2002

시판되는 보리차 3종(티백형 2종 알곡형 1종)이 우식유발 세균인 Streptococcus mutans와Streptococcus sobrinus가 타액피복 수산화인회석에 부착되는 정도와 이들 세균의 체표소수성에 미치는 영향에 대해 평가하였다. 모든 실험군에서 보리차로 처리하였을 때 수산화인회석에의 부착능과 세균의 체표소수성은 감소하였고 이 값은 보리차의 종류와 처리방법에 따라 상이하였다. 이러한 결과는 보리차에 함유된 활성성분인 catechins와 melanoidins의 영향 때문인 것으로 추측되며 보리차로 전 처리한 수산화인회석에 세균이 부착하는 정도가 감소한 것은 활성물질이 흡착되어 치아표면의 수용체가 세균의 부착소와 작용하는 것을 방해함으로써 치아우식증 병인론의 초기 단계인 부착에 영향을 미칠 수 있다는 것을 의미한다. 본 연구결과 보리차가 우식유발 세균의 주요 독력인자 중 하나인 부착능을 억제하므로 보리차가 이러한 세균이 일으키는 치아우식증을 억제할 수도 있다는 가능성을 보여준다.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.28-34
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• 2008

Biofilm formation in association with the intercellular adhesion (icaADBC) gene cluster is a serious problem in nosocomial infections of Staphylococcus aureus. In all 112 S. aureus strains tested, the ica genes were present, and none of these strains formed biofilms. The biofilm formation is known to be changeable by environmental factors. We have found about 30% of phase variation in these strains with treatment of tetracycline, pristinamycin, and natrium chloride. However, this phenotype disappeared without these substances. Therefore, we have constructed stable biofilm-producing variants through a passage culture method. To explain the mechanism of this variation, nucleotide changes of ica genes were tested in strain S. aureus 483 and the biofilm-producing variants. No differences of DNA sequence in ica genes were found between the strains. Additionally, molecular analysis of three regulatory genes, the accessory gene regulator (agr) and the staphylococcal accessory regulator (sarA), and in addition, alternative transcription factor ${\sigma}^B$ (sigB), was performed. The data of Northern blot and complementation showed that SigB plays an important role for this biofilm variation in S. aureus 483 and the biofilm-producing variants. Sequence analysis of the sigB operon indicated three point mutations in the rsbU gene, especially in the stop codon, and two point mutations in the rsbW gene. This study shows that this variation of biofilm formation in S. aureus is deduced by the role of sigB, not agr and sarA.

• The Journal of Advanced Prosthodontics
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• 제7권6호
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• pp.484-495
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• 2015

PURPOSE. This study was to evaluate the effects of bacterial cellulose (BC) membranes as a barrier membrane on guided bone regeneration (GBR) in comparison with those of the resorbable collagen membranes. MATERIALS AND METHODS. BC membranes were fabricated using biomimetic technology. Surface properties were analyzed, Mechanical properties were measured, in vitro cell proliferation test were performed with NIH3T3 cells and in vivo study were performed with rat calvarial defect and histomorphometric analysis was done. The Mann-Whitney U test and the Wilcoxon signed rank test was used (${\alpha}<.05$). RESULTS. BC membrane showed significantly higher mechanical properties such as wet tensile strength than collagen membrane and represented a three-dimensional multilayered structure cross-linked by nano-fibers with 60 % porosity. In vitro study, cell adhesion and proliferation were observed on BC membrane. However, morphology of the cells was found to be less differentiated, and the cell proliferation rate was lower than those of the cells on collagen membrane. In vivo study, the grafted BC membrane did not induce inflammatory response, and maintained adequate space for bone regeneration. An amount of new bone formation in defect region loaded with BC membrane was significantly similar to that of collagen membrane application. CONCLUSION. BC membrane has potential to be used as a barrier membrane, and efficacy of the membrane on GBR is comparable to that of collagen membrane.

• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.83-95
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• 1997

The degradation mode of lignocellulose by anaerobic ruminal cellulolytic bacterium Ruminococcus albus F-40 was investigated. Birchwood holocellulose and filter paper were incubated as the sole carbohydrate sources with using the Hungate techniques. After 2 or 4 days of incubation, samples were employed for chemical and electron microscopic evaluations. The degradation rate of cellulosic substrates and the adhesion rate of bacteria to the substrates increased proportionally with the decrease of relative crystallinity of cellulose, indicating the preferential breakdown of amorphous cellulose, by this bacterium. X-ray diffraction analyses and polarized light microscopy showed, however, that crystalline cellulose was also degraded by R. albus. FT-IR spectra indicated that not only cellulose but hemicellulose was also degraded by this bacterium. Electron microscopic investigations showed the protuberant structures on the surface of R. albus. These structures were much more significant when bacterial cells were grown in the media containing insoluble substrates, such as cellulose, indicating clearly that bacterial protuberant structures were induced by the substrates. Protuberant structures extended from the bacterial cells adhered tightly to the substrates and numerous vesicles covered the surface of cellulosic substrates affected. Cellulosome-like structures were distributed on the cellulose matrix. Electron microscopic works showed that diverse surface organells of R. albus were involved in the degradation of cellulosic materials. SEM examinations showed the breakdown of cellulose by R. albus was proceeded by severeal routes : short fiber formation, defibrillation and destrafication of cellulose microfibril.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.635-638
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• 2003

For the acute assessment on biological toxicity of wastewater, surface plasmon resonance(SPR) based cell viability detection was performed using gold surface-confined cell as a result of adhesion-modifying chemicals. Escherichia coli O157:H7 (E. coli O157:H7) was investigated after exposure to EDTA. Cells were immobilized on gold coated slide glass for SPR analysis by the method of cross-linking carboxyl group on the bacterial surface with amine group of poly-L-lysine that had been coupled to the gold surface modified by a self-assembled monolayer of 11-mercaptounde canoic acid (11-(MUA)). Reflective intensity of each flow step was changed with respect to confect of ethylenediaminetetraacetic acid (EDTA) disodium salt and phosphate-buffered saline (PBS) solution. The proposed detection technique can be used for biological toxicity test.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.183-186
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• 2011

Biochemical methods were selected to evaluate the role of exopolymeric substances in the stability of biofilms used in bioremediation processes. Biofilms of Thiomonas arsenivorans formed on pozzolana were thus treated with pronase (protein target), lectins (Con A or PNA), calcofluor or periodic acid (polysaccharides target), DNase (DNA target), and lipase (triglycerides target). Neither protease nor DNase treatments had any effect on bacterial adhesion. Lectins and calcofluor treatments mainly affected young biofilms. Lipase treatment had a noticeable effect on biofilm stability whatever the biofilm age. Results suggest that it would be an increased resistance of mature biofilms that protects them from external attacks.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.93-96
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• 1998

NAPL이 다핵방향족화합물의 하나인 phenanthrene 의 생분해에 미치는 영향을 알아보았다. Pseudomonas putida CRE7 을 이용한 실험에서 NAPL 의 첨가로 인한 가장 큰 차이는 미생물의 소수성의 변화였다. 소수성이 증대됨으로써 phenanthrene 의 가용성이 증대되었으며, 이로 인해 더 많은 양의 오염물 분해가 이루어졌다. 생물학적 분해의 관찰은 발생되어지는 $^{14}$ $CO_2$의 radioactivity 측정을 통해 이루어졌으며, 미생물의 소수성 측정은 bacterial adhesion to hydrocarbon (BATH) assay 를 이용하였다.