• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.437-447
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• 2018

Visible-light-driven wide bandgap semiconductor photocatalysts were commonly developed via doping or coupling with another narrow bandgap metal oxide. However, these approaches required extra processing. The aim of study was to evaluate the photocatalytic performance of narrow bandgap $WO_x$ nanoparticles. A mixture of $WO_2$ and $WO_3$ nanoparticles were synthesized using solution precipitation technique. The photodegradation of RhB by these nanoparticles more effective in UV light than in visible light. In antibacterial susceptibility assay, $WO_x$ nanoparticles demonstrated good antibacterial against Gram-positive bacteria. The cell wall of bacterial was the main determinant in antibacterial effect other than $W^{4+}/W^{6+}$ ions and ROS.

• 대한약침학회지
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• 제25권2호
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• pp.101-105
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• 2022

Objectives: This study aims to determine the Fractional Inhibitory Concentration Index (FICI) of combinations of Melastoma malabathricum leaf fraction with ciprofloxacin or gentamicin against pathogenic bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus cereus, isolated from Diabetic Foot Ulcer (DFU) patients. Methods: We tested concentrations of 45%, 55%, 65%, and 75% of gentamicin and ciprofloxacin using dilution and agar diffusion methods. The combination of M. malabathricum leaf extract with these antibiotics was tested in vitro against all three bacteria. Results: The combination of M. malabathricum leaf extract and ciprofloxacin gave a FICI value of 0.5, indicating synergistic antibacterial activity against the test bacteria. Conclusion: The results show that the antibacterial effect of a combination of high doses of the leaf extract with either antibiotic is greater than that of the leaf extract and the antibiotics in single use.

• Restorative Dentistry and Endodontics
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• 제39권2호
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• pp.109-114
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• 2014

Objectives: Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods: Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30). The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683) and Lactobacillus (PTCC 1643) were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at $37^{\circ}C$ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results: Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05). The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05). There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions: Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus.

• 동의생리병리학회지
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• 제26권6호
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• pp.886-893
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• 2012

Methicillin-Resistant Staphylococcus aureus (MRSA) is a cephalosporin and beta-lactam antibiotic-resistant strain. In most cases, MRSA is spread from infected patients and infection rates are growing increasingly. Furthermore, increased resistance to antibiotics is causing serious problems in the world. Staphylococcus aureus is responsible for both nosocomial and community-based infections that range from relatively minor skin and soft tissue infections to life-threatening systemic infections. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. In this study, we investigated antimicrobial activity of oriental medicine prescription against MRSA. The minimum inhibitory concentration (MIC) of Sohamhyung-tang water extract against S. aureus strains ranged from 500 to 2,000 ${\mu}g/mL$, so we have it confirmed that a strong antibacterial effect. Also, the combinations of Sohamhyung-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Sohamhyung-tang water extract against MRSA have antibacterial activity, it has potential as alternatives to antibiotic agent. We suggest that the Sohamhyung-tang water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.23-27
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• 1994

Wound healing and antibacterial effects of solcoseryl-micronomicin combination gel on an open wound were studied in mice. A simple model was designed for assessing the effects. Using the model, we compared the efficacy of a combined topical gel of solcoseryl and micronomicin with those gels of solcoseryl or micronomicin alone. From the results of our experiment, the wound healing effect of open wounds by treatment with the combination gel was significantly enhanced when compared with those by treatment with solcoseryl gel or micronomicin gel alone. And the antibacterial effect of the combination gel was higher than those of solcoseryl gel or micronomicin gel alone.

• 한국환경과학회지
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• 제27권1호
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• pp.47-53
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• 2018

In this study, high-purity silver nanocolloids were synthesized by an electrolytic reaction, and the effect of temperature on the nanocolloid concentration was analyzed by performing the reaction at $70^{\circ}C$ and $90^{\circ}C$. The antibacterial properties of the thus-synthesized silver nanocolloids were also studied. When the synthesis was performed at $90^{\circ}C$, the concentration of silver nanocolloid increased to 14 mg/L after 5 min, 1756 mg/L after 30 min, and 2147 mg/L after 60 min. The concentration of silver nanocolloid synthesized by electrolytic reaction at $70^{\circ}C$ and $90^{\circ}C$ for 60 min was 1,882 mg/L and 2147 mg/L, respectively. The preferred temperature at which the electrolytic synthesis is performed is $70^{\circ}C$ to obtain high concentrations of 1,000 mg/L or more. The antibacterial performance of the thus-synthesized silver nanocolloids was 99.9% for E. coli and 99.5% for Pseudomonas aeruginosa.

• 생약학회지
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• 제17권1호
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• pp.85-90
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• 1986

It has been elucidated that magnolol and honokiol, isolated from the stem bark of Magnolia obovata, had potent antibacterial activity against a cariogenic bacterium Streptococcus mutans. They also show a significant antibacterial activity against Bacillus anthracis, which causes malignant pustule and woolsorter disease in human. Some hydroxybiphenyl derivatives are synthesized from starting materials, phenylphenols and biphenols by means of Claisen's rearrangement and Elb's method to develop more potent antibacterial chemicals and to investigate the structure-activity relationships. The introduction of allyl groups to the aromatic rings of starting materials shows increase of antibacterial activities, but the number and positions of them do not effect their activities. Furthermore, the introduction of hydroxy group to aromatic rings also increases the activity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.37-40
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• 2003

The antibacterial action of violet pigment, a mixture of violacein and deoxyviolacein, isolated from phychrotrophic bacterium RT102 strain was examined, and the operational conditions for the effective production of violet pigment were studied. The antibacterial activity of the violet pigment was confirmed for several bacteria such as Bacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, and Pseudomonas aeruginosa, and the high concentration of violet pigment, above about 15mg/L, caused not only growth inhibition but also death of cells. The growth properties of RT102 strain were clarified under various incubation conditions such as pH, temperature, and dissolved oxygen concentration. The maximum violet pigment concentration, i.e. 3.7 g/L, and the maximum productivity of violet pigment, i.e. 0.12 g .L$\^$-1/H$\^$-1/, were obtained in a batch culture of pH 6, 20$^{\circ}C$, and 1 mg/L of dissolved oxygen concentration.

• 대한소아치과학회지
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• 제48권2호
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• pp.198-208
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• 2021

이 연구의 목적은 키토산 첨가 수산화칼슘 근관 충전재의Enterococcus Faecalis에 대한 항균 효과 및 물리적 성질을 알아보는 것이다. 저, 중, 고분자량의 키토산 분말을 수산화칼슘 근관 충전재와 혼합하였고, 각 분자량 별로 키토산 분말을 1.0, 2.0, 5.0 wt%로 첨가하였다. E. faecalis를 배양하여 1 × 10⁶ CFU/ml로 조정하였다. 항균 효과 실험을 위해 2.0 wt% 키토산의 3가지 다른 분자량, 3가지 다른 농도의 고분자량 키토산을 수산화칼슘 근관 충전재와 혼합하였다. 기준 파장 600 nm인 570 nm에서 분광광도계를 이용하여 상층액의 흡광도를 측정하였다. 유동성, 피막도 및 방사선 불투과성은 ISO 6876 : 2012에 의거하여 측정하였다. 키토산을 포함하는 모든 분자량 유형의 실험군은 키토산을 첨가하지 않은 대조군에 비해 E. faecalis 성장 억제 효과를 보였다. 고분자량 키토산 첨가 군에서 가장 좋은 항균 효과를 보였다(p < 0.05). 또한 키토산 첨가량이 감소할수록 항균 효과도 감소하였다(p < 0.05). 키토산을 함유하는 수산화칼슘 근관 충전재의 모든 분자량 군은 키토산 함량의 증가 따라 유동성 및 방사선 불투과성이 감소하고 피막도가 증가하는 경향을 보였다. 1.0 wt% 저분자량 키토산의 첨가는 기존 수산화칼슘 근관 충전재와 비교하여 물성에 큰 차이를 보이지 않았다. 연구 결과를 종합하였을 때, 수산화칼슘 근관 충전재에 첨가하여 항균성 강화와 적절한 물성을 얻기 위해선 2.0 wt%의 키토산 분말의 첨가가 적정하다. 키토산의 항균 효과를 고려할 때, 키토산의 근관 치료 및 소아치과 분야에서의 적용을 위한 추가적인 연구가 필요할 것으로 사료되었다.

• ALGAE
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• 제29권1호
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.