• 대한치과의사협회지
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• 제21권7호통권170호
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• pp.573-577
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• 1983

The antimicrobial action of various dental cements evaluated against common micro-organisms most frequenty found within the components of the normal bacterial flora of oral cavity. They include Streptococcus mutans (2 strains), Lactobacillus acidophilus, Actinomyces viscosus, and Streptococcus sanguis. The test was done by the use of brain heart infusion (BHI) agar plates. A standard mix of each cement was made and placed on the plates which were seeded with a standard culture of microorganisms. After incubation, the halo of bacterial growth inhibition around the cement was identified and its size was measured. Some of the cements tested had obvious antibacterial effect. The cements listed in decreasing order of effectiveness are 1) zinc phosphate and oxyphosphate, 2) silicate, 3) zinc oxide-eugenol, 4) calcium hydroxide, and 5) carboxylate.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1014-1021
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• 2019

In the bacterial community, unicellular organisms act together as a multicellular being. Bacteria interact within the community and programmed cell death (PCD) in prokaryotes is a sort of altruistic action that enables the whole population to thrive. Genetically, encoded cell death pathways are triggered by DNA damage or nutrient starvation. Given the environmental and bacterial diversity, different PCD mechanisms are operated. Still, their biochemical and physiological aspects remain unrevealed. There are three main pathways; thymineless death, apoptosis-like death, and toxin-antitoxin systems. The discovery of PCD in bacteria has revealed the possibility of developing new antibiotics. In this review, the molecular and physiological characteristics of the three types of PCD and their development potential as antibacterial agents are addressed.

• Journal of Pharmaceutical Investigation
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• 제12권1호
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• pp.1-11
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• 1982

Silver sulfadiazine has been introduced to replace silver nitrate in the topical treatment of extensive burns and this drug exerts a prominent antibacterial action against Pseudomonas aeruginosa. The compound is painless upon application and insufficient sulfadiazine is absorbed to cause crystalluria. The primary purpose of the study was to clarify the antimicrobial action of zinc sulfadiazine ointment in comparison with silver sulfadiazine ointment as well as the pharmaceutical properties of the zinc sulfadiazine preparations. The results are summerized as followings: 1) The optimum ratio of two substrate compounds for the synthesis of zinc sulfadiazine are 2 moles of sulfadiazine and 1 mole of zinc sulfate at pH 6.0. 2) The stability of zinc sulfadiazine ointment preparation by using polyethylene glycol base, Beeler's base or polyoxyl 40 stearate base was more stable than that of silver sulfadiazine preparations. 3) The antimicrobial action of zinc sulfadiazine exhibits a stronger antimicrobial activity than that of sulfadiazine against Staphylococcus aureus but the opposite is true against Pseudomonas aeruginosa.

• 생명과학회지
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• 제29권12호
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• pp.1386-1392
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• 2019

본 연구에서는 천연물유래 구강건강소재로써 염료식물의 이용 가능성을 알아보기 위해 오리나무, 옻나무, 치자나무, 황칠나무, 황벽나무, 회화나무 줄기 추출물의 구강미생물에 대한 항균활성을 조사하였다. 6 종의 국내 자생 염료식물의 줄기에서 추출한 에탄올 추출물 중 오리나무 줄기 추출물(1 mg/disc)이 치주질환 원인균인 P. gingivalis KCTC5352에 대해 가장 우수한 항균활성을 나타내었다. 오리나무 줄기 추출물은 P. gingivalis KCTC5352에 대해 양성대조구로 사용한 chlorhexidine과 유사한 항균활성을 나타내었으며 P. gingivalis KCTC5352의 MIC는 0.4 mg/ml였고 MBC는 0.6 mg/ml였다. 오리나무 줄기 추출물이 0.2-2.0 mg/ml 농도로 처리된 배양액에서 P. gingivalis KCTC5352의 바이오필름 생성율과 세균 생육은 추출물의 농도가 증가할수록 저해되는 경향을 보였다. 또한 P. gingivalis KCTC5352의 superoxide dismutase (SOD)와 섬모에 대한 mRNA 발현도 추출물의 농도가 높아질수록 감소하는 것을 확인할 수 있었다. 이상의 결과를 종합하면 오리나무 줄기 추출물은 치주질환 원인균인 P. gingivalis KCTC5352에 대한 항균활성과 생물막 생성 억제능이 우수하기 때문에 천연물유래 구강건강소재로써 이용 가능성이 높을 것으로 판단된다.

• 약학회지
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• 제37권2호
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• pp.136-142
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• 1993

To a suspension of 1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-{3,7-diazabicyclo[3.3.0]oct-1(5)-en-3-yl}-4-oxo-3-quinoline carboxylic acid(C1) in sodium hydroxide solution and water is added dropwise with stirring carbon disulfide. [6R-[6$\alpha$, 7$\beta$(Z)]]-7-[[[2-Amino-4-thiazoly)methoxyimino]-acetyl]amino]-3-[[[[7-( 3-carboxy-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxo-7-guinolonyl)-3,7-diazabicyclo[3.3.0]oct-1(5)-en-3-yl]thioxomethyl]thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid (DACD) was synthesized from 1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-[7-(mercapto) thioxomethyl-[3,7-dia zabicyclo[3.3.0]oct-1(5)-en-3-yl}]-4-oxo-3-quinoline carboxylic acid disodium salt(C2) and cefotaxime. The invitro activity of novel dual-action cephalosporin, DACD, was compared with the in vitro activities of CENO(cefotaxime 3'-norfloxacin dithiocarbamate), cefotaxime, and norfloxacin against a variety of bacterial species. In vitro activity of DACD was superior to that of norfloxacin against Streptococcus pyogenes. Against Gram-positive and Gram-negative bacteria, its activity was almost equal to that of CENO.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1299-1306
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• 2015

This study aims to investigate the mechanism of action of the cinnamon bark essential oil (CB), when used singly and also in combination with piperacillin, for its antimicrobial and synergistic activity against beta-lactamase TEM-1 plasmid-conferred Escherichia coli J53 R1. Viable count of bacteria for this combination of essential oil and antibiotic showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis on the stability of treated cultures for cell membrane permeability by CB when tested against sodium dodecyl sulfate revealed that the bacterial cell membrane was disrupted by the essential oil. Scanning electron microscopy observation and bacterial surface charge measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed reduction, indicating the possibility of the presence of quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%), and eugenol (6.57%) were the major components in the essential oil. From this study, CB has the potential to reverse E. coli J53 R1 resistance to piperacillin through two pathways; modification in the permeability of the outer membrane or bacterial QS inhibition.

• Molecular & Cellular Toxicology
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• 제3권2호
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• pp.90-97
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• 2007

8-Hydroxyquinoline is used as antibacterial agent and antioxidant based on its function inducing the chelation of ferrous ion present in host resulting in production of chelated complex. This complex being transported to cell membrane of bacteria and fungi exerts antibacterial and antifungal action. In this study, we have carried out in vitro genetic toxicity tests and microarray analysis to understand the underlying mechanisms and the mode of action of toxicity of 8-hydroxyquinoline. TA1535 and TA98 cells were treated with 8-hydroxyquinoline to test its toxicity by basic genetic toxicity test, Ames and two new in vitro micronucleus and COMET assays were applied using CHO cells and L5178Y cells, respectively. In addition, microarray analysis of differentially expressed genes in L5178Y cells in response to 8-hydroxyquinoline were analyzed using Affymatrix genechip. The result of Ames test was that 8-hydroxyquinoline treatment increased the mutations in base substitution strain TA1535 and likewise, 8-hydroxyquinoline also increased mutations in frame shift TA98. 8-Hydroxyquinoline increased micronuclei in CHO cells and DNA damage in L5178Y. 8-Hdroxyquinoline resulted in positive response in all three tests showing its ability to induce not only mutation but also DNA damage. 783 Genes were initially selected as differentially expressed genes in response to 8-hydroxyquinoline by microarray analysis and 34 genes among them were over 4 times of log fold changed. These 34 genes could be candidate biomarkers of genetic toxic action of 8-hydroxyquinoline related to induction of mutation and/or induction of micronuclei and DNA damage. Further confirmation of these candidate markers related to their biological function will be useful to understand the detailed mode of action of 8-hydroxyquinoline.

• Toxicological Research
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• 제27권1호
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• pp.31-36
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• 2011

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC). The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute). All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from $0.6\;{\mu}g/ml$ to $5000\;{\mu}g/ml$. The lowest MIC ($0.6\;{\mu}g/ml$) and MBC ($1.22\;{\mu}g/ml$) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively.

• The Plant Pathology Journal
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• 제32권2호
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• pp.157-161
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• 2016

Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika.

• 한국식품과학회지
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• 제20권3호
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• pp.357-362
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• 1988

김치로부터 호기성 세균들을 분리 동정하고 이들의 생육에 대한 마늘의 영향을 조사한 결과는 다음과 같다. 분리된 균은 모두 21종으로서 Bacillus spp. 이 11종, Staphylococcus spp. 이 2종, Micrococcus, Flavobacterium이 1종씩 이었으며 Enterobacteriaceae와 Vibrionaceae에 속하는 균주가 각각 1종과 4종이었다. 이들 세균은 마늘 추출물이 첨가된 nutrient broth에서 생육이 저해되었는데 저해의 정도는 미생물의 종류에 따라 달랐으며 마늘농도가 높으면 억제효과도 상대적으로 컸다. 이 억제작용은 마늘 추출물의 호기성 미생물에 대한 사멸작용 때문인 것을 알 수 있었다.