• 한방재활의학과학회지
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• 제25권2호
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• pp.1-13
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• 2015

Objectives Methicillin-Resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. In this study, we investigated the antimicrobial activity ofethanol extract of Haedokgeumhwa-san (HGH) which prescription is composed of korean medicine against MRSA. Methods The antibacterial activity of HGH extract was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method (minimal inhibitory concentration; MIC), checkerboard dilution test, and time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors. The checkerboard dilution test was used to examined synergistic effect of ampicillin, oxacillin, ciprofloxacin, vancomycin, gentamicin and norfloxacin in combination with HGH ethanol extract. A time-kill assay was performed a survival curve which was obtained by plotting viable colony counts depending on time on bacterial growth. Results The minimum inhibitory concentration (MIC) of ethanol extract (HGH) ranged from 1,000 to $2,000{\mu}g/mL$ against all the tested bacterial strains, respectively. We are able to confirm that HGH extract has potentially strong antibacterial activity. In the checkerboard dilution test, fractional inhibitory concentration index of HGH in combination with antibiotics indicated synergy or partial synergism against S. aureus. A time-kill study showed that the growth of the tested bacteria was considerably inhibited after 8 hr of treatment with the combination of HGH with selected antibiotics. For measurement of cell membrane permeability, HGH $250{\sim}1,000{\mu}g/mL$ along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (Tris) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide ($NaN_3$) was used as an inhibitor of ATPase. TX, Tris, DCCD and $NaN_3$ cooperation against S. aureus showed synergistic action. Accordingly, antimicrobial activity of HGH was affected by cell membrane and inhibitor of ATPase. Conclusions These results suggest that Haedokgeumhwa-san extract has antibacterial activity, and that HGH extract offers a potential as a natural antibiotic against MRSA.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.231-232
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• 1989

Although it has been known that organometallic $\beta$-lactam compounds improve the resistance to $\beta$-lactamases as well as their pharmacological activities, only a few results on organometallic $\beta$-lactam antibiotics were reported. In the course of our extensive study on the development of new cephalosporins, we were interested in organotin compounds since they show some biological activities.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.161-169
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• 2001

Lactic acid producing bacteria were isolated from baby feces and characterized to be used as a probiotic with anti Helicobacter pylori functions. The selected bacteria had inhibition activity on the adherance and growth of H. pylori. These bacteria had additional beneficial characteristics for the probiotic such as antibacterial activity, antitumor activity, immunostimulation activity, resistance to antibiotic and bile salt, ability to bind to the intestinal cells, and safe for the human use.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.101.2-102
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• 2003

The ability of P. chlororaphis O6 to induce resistance to Erwinia carotovora subsp. carotovara SCCI and to promote growth in tobacco was demonstrated in microtiter assays on plants pre-inoculated at the root level with the bacteria before challenge with the leaf pathogen. To identify th bacterial determinants involved in induced systemic resistance and plant growth promotion, cell culture of O6 grown in King's medium B was fractionated with organic solvents and purified using various columns. in vivo and in vitro assays with samples from successive fractionation steps of the O6 supernatant led to the conclusion that antibacterial compounds were observed in aqueous layer, and to the isolation of fractions containing metabolites that retained most of the resistance-inducing activity (70：30, methanol：water) and the plant growth promotion (80：20 and 90：10, methanol：water) after ODS column chromatography. Although these molecules remain to be purified further and structurally characterized, its isolation is an addition to the range of determinants from plant growth-promoting rhizobacteria known to stimulate plant defence.

• 한국재료학회지
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• 제24권4호
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• pp.175-179
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• 2014

Ti and Ti alloys have been extensively used in the medical and dental fields because of their good corrosion resistance, high strength to density ratio and especially, their low elastic modulus compared to other metallic materials. Recent trends in biomaterials research have focused on development of metallic alloys with elastic modulus similar to natural bone, however, many candidate materials also contain toxic elements that would be biologically harmful. In this study, new Ti based alloys which do not contain the toxic metallic components were developed using a theoretical method (DV-$X{\alpha}$). In addition, alloys were developed with improved mechanical properties and corrosion resistance. Ternary Ti-Ag-Zr alloys consisting of biocompatible alloying elements were produced to investigate the alloying effect on microstructure, corrosion resistance, mechanical properties and biocompatibility. The effects of various contents of Zr on the mechanical properties and biocompatibility were compared. The alloys exhibited higher strength and corrosion resistance than pure Ti, had antibacterial properties, and were not observed to be cytotoxic. Of the designed alloys' mechanical properties and biocompatibility, the Ti-3Ag-0.5Zr alloy had the best results.

• 약학회지
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• 제48권1호
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• pp.20-26
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• 2004

Twelve strains of Bifidobacterium spp. were isolated from the feces of healthy Korean 20∼30 years. The identification of genera from isolates were performed by the microscopic observation and fructose-6-phosphate phosphoketolase (F6PPK) activity which is the key enzyme to distinguish the Bifidobacterium spp. from other anaerobic bacteria. To determine the antibacterial resistance patterns, minimum inhibitory concentration (MIC) of several antibiotics (including anti-tuberculosis agents) was determined. Five of the isolate!, showed the high degree of resistance to vancomycin. To investigate the genetic diversity between isolates and type strain of Bifidobacterium spp. from KCTC, we peformed the RAPD-fingerprinting. Using a total set of four primers, it is possible to distinguish the isolates and Bifidobacterium spp. from KCTC. Thus, Bifidobacterium strains isolated from our samples may be a new species or strains of Bifidobacteriurn genera, and have the potential as a probiotics.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.541-544
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• 2004

The purpose of this study is to examine the antibiotic and physical properties of antibiotic concrete added inorganic liquor-type antibiotic agent(as named for Antibio-C) as the basic data for the development of antibiotic concrete. The main experimental variables were the types of antibiotic agents and it is tested for the properties of antibiotic, flow, compressive strength, crack-resistance and durability of concrete. As results, concrete containing antibiotic agent presented the strong antibiotic activities compared with non-added concrete. Also antibiotic concrete showed the higher or equality properties than non-added concrete with respect to compressive strength, crack resistance and durability such as neutralization depth.

• International Journal of Oral Biology
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• 제30권4호
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• pp.125-130
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• 2005

Thrombin-induced platelet microbicidal proteins (tPMP) are antibacterial proteins released when platelets are stimulated by thrombin. It has been reported that tPMP has antibacterial activity against various bacterial species including causative agents of infective endocarditis. Most of the oral streptococci have resistance to the killing by tPMP and this fact may play an important role as a virulence factor in infective endocarditis. However, the susceptibility and resistance mechanism of oral streptococci for tPMP have not been revealed yet. In this study, the killing mechanism of tPMP for oral streptococci has been investigated. Streptococcus rattus BHT, a susceptible strain, and Streptococcus gordonii DL1, a resistant strain, have been used in this study. tPMP was isolated from platelet after stimulation with thrombin. Cell membrane depolarization was examined with 3,3'-dipropylthiodicarbocyanine iodide ($DiSC_3$), membrane potential-sensitive cyanine dye, by fluorescence spectrophotometry. The permeabilization of cell membrane by tPMP was investigated with propidium iodide (PI) by flow cytometry. tPMP susceptible S. rattus BHT showed the increase of the $DiSC_3$ fluorescence level meaning depolarization of cell membrane and increase of the uptake of PI which means permeabilization of cell membrane. However, tPMP resistant S. gordonii DLI did not show depolarization and permeabilization. These results indicate that the increasing depolarization and permeabilization of oral streptococcal cell membrane are associated with the bactericidal activity of tPMP.

• Advances in Traditional Medicine
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• 제3권3호
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• pp.111-122
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• 2003

Plants of the genus Hypericum (Family - Hypericaceae) are herbs, shrubs or small trees and are distributed chiefly in the temperate regions of the world. About 400 different species of Hypericum are available throughout the globe and 20 species occur in India, including a few cultivated in gardens. Almost all plants of the genus Hypericum are widely used in folk medicine. Several potent phytoconstituents from different Hypericum species have led to the isolation of antibacterial, antifungal and cytotoxic compounds. With the development of resistance and cross resistance with different microorganisms and the evolution of so many deadly diseases the screening and evaluation of the phytoconstituents so much so the development of varied phytoconstituents for the drug development for these deadly diseases is utmost essential in every aspects. The present review on the antimicrobial use of different Hypericum reports the findings from and extensive literature search on the Hypericum species around the globe that have been assessed for antimicrobial and antiviral activity. An attempt has been made through this review to summarize the information in this aspect in order to highlight the promising species of this genus which are worthy for further investigation as leads for drug development. Over 31 different Hypericum species have been reported to possess such activities with their varied number of phytoconstituents. Sixteen different constituents of six different classes of phytoconstituents have been reported to be present in different varieties of Hypericum, which may be considered responsible for this activity.

• 대한임상검사과학회지
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• 제50권4호
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• pp.431-437
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• 2018

Acinetobacter baumannii는 광범위한 항생제에 대한 저항성으로 인해 감염된 환자의 사망률이 높아지는 적색 경보 병원체로 분류됩니다. 이 연구에서 다제 내성 A. baumannii(MRAB)의 18가지 임상 분리 균주에 대해 일부 에센셜 오일(티트리, 로즈마리, 라벤더 오일)의 항균 활성을 평가하고자 하였다. Carbapenemase 선별을 위한 Hodge 시험법은 A. baumannii의 20 가지 균주가 모두 imipenem에 내성이 있음을 보여주었습니다. 다제 내성 미생물의 확인은 VITEK 시스템을 통해 수행하였다. 에센셜 오일의 항균 활성은 MRAB에 대한 디스크 확산 방법으로 평가하였다. 디스크 확산 방법에서 tee tree는 라벤더 오일에 비해 억제 크기가 가장 크게 증가했으며, 로즈마리는 항균 효과가 없었다. 티 트리 오일은 가장 일반적인 인간 병원균 및 MRAB 감염의 치료 및 예방을 위한 대체 천연 제품으로 유용할 것으로 보인다. 따라서 이 연구의 결과는 다제 내성 A. baumannii의 항균 효과를 입증했으며, 미래에 천연 에센셜 오일을 사용하는 손 소독제와 같은 항균제로 사용될 것으로 예상됩니다.