• The Plant Pathology Journal
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• 제19권3호
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• pp.143-147
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• 2003

Sensitivity of Phytophthora infestans isolates to fungicides metalaxyl and ethaboxam in Korea was examined with 260 isolates for 3 years (9 isolates in 2000,93 isolates in 2001, and 158 isolates in 2002). Both Al and A2 mating types were found from the isolates collected for 3 years. Al mating type was dominant in the population with 8 isolates (88.9%) in 2000, 84 isolates (89.4%) in 2001, and 138 isolates (87.3%) in 2002. Only some isolates from diseased tomatoes in Buyergun and diseased potatoes in Pyeongchanggun were of the A2 mating type. As for metalaxyl sensitivity, 77.0% of the isolates were moderately resistant with 8 isolates (88.9%) in 2000, 73 isolates (77.7%) in 2001, and 120 isolates (75.9%) in 2002. Meanwhile, those found resistant were 1 isolate (11.1%) in 2000, 16 isolates (17.0%) in 2001, and 33 isolates (20.9%) in 2002. Only 5 isolates (3.2%) were sensitive to metalaxyl in 2002. There was no significant difference in the sensitivity among years. As for ethaboxam, no isolate was able to grow at 5.0 $\mu\textrm{g}$ /ml, and only four isolates (1.5 %) grew at 1.0 $\mu\textrm{g}$ /ml with heavy retardation compared with the untreated control. Based on these 3-year results, the minimum inhibitory concentration (MIC) of ethaboxam to p. infestans was determined to be 0.2-1.0 $\mu\textrm{g}$ /ml. Results indicate that resistance development by p. infestans to ethaboxam is not likely to occur in the natural condition. furthermore, there was no indication of cross resistance between metalaxyl and ethaboxam because all the isolates, regardless of classification for their sensitivity to metalaxyl, were not able to grow at 5.0 $\mu\textrm{g}$ /ml of ethaboxam.

• 생약학회지
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• 제45권2호
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• pp.168-173
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• 2014

The aim of this study was to evaluate the anti-helicobacter activity of the ethanol extract of Sohamhyoongtang (Coptidis Rhizoma, Pinelliae Tuber and Trichosanthis Semen) and Coptidis Rhizoma total alkaloids, which is one of the components of Sohamhyoongtang. Crude ethanol extract of Sohamhyoongtang (ESHHT) and Coptidis Rhizoma total alkaloids (CRTA) were used for this experiment. Five different types of H. pylori (including H. pylori 26695) were used as test strain. To determine anti-helicobacter activity, minimum inhibitory concentration (MIC) was determined by agar dilution method. The effect of ESHHT and CRTA on the gene expression of H. pylori was investigated by quantitative realtime-PCR (qRT-PCR). MICs of ESHHT against five H. pylori strains were $250{\sim}500{\mu}g/ml$ and MICs of CRTA against five H. pylori strains were $50{\sim}200{\mu}g/ml$. Four representative virulence genes of H. pylori, cagA, ureA, ureB and ureI were tested as target genes for qRT-PCR. According to the qRT-PCR results, both ESHHT and CRTA markedly repressed the expression of cagA gene of H. pylori 26695 (6.91 and 20 folds respecively). These results showed that the ESHHT and CRTA demonstrated antihelicobacter properties, suggesting their potential use in gastritis or duodenal ulcer.

• 한국식품영양학회지
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• 제10권2호
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• pp.174-179
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• 1997

오배자 등 민간생약제와 포도과피 추출물의 항균활성과 GTase 활성저해능에 대하여 조사하였다. 항균활성과 GTase 저해 활성능은 오배자와 적포도 과피의 물추출물이 가장 우수한 것으로 나타났다. 오배자와 적포도 과피 추출물의 methanol 분획물은 B. subtilis와 E. coli 균주에 대해서 강한 항균활성을 나타내었다. 오배자 추출물의 methanol 분획물은 B. subtilis와 E. coli에 대한 최소 저해 농도가 각각 1.0mg/ml과 3.0mg/ml이었고, 포도과피 추출물 추출물의 methanol 분획물의 GTase활성의 80% 저해율에 대한 농도는 각각 1.08$\times$10-3mg/ml과 1.08$\times$10-2mg/ml이었다. 두 추출물의 항균활성과 GTase활성 저해의 주요 화합물은 polyphenol 화합물 계통으로 추정된다.

• 한국수산과학회지
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• 제43권6호
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• pp.642-647
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• 2010

This study examined the antimicrobial activity of Myagropsis yendoi (MY). The antimicrobial activity of ethanol and aqueous MY extracts were measured using a paper disc assay. The MY ethanol extract had the best antimicrobial activity. It inhibited the growth of Candida tropicalis and Gram-positive bacteria such as Bacillus subtilis, Listeria innocua, L. monocytogenes, and Staphylococcus aureus at 4 mg/mL. The minimum inhibitory concentration (MIC) of the MY ethanol extract ranged from 0.1 to 0.5%. The MY ethanol extract inhibited the growth of B. subtilis and L. innocuaat concentrations of 0.15% and 0.1%, respectively. The antimicrobial activity of the MY ethanol extract was not affected by heating at $121^{\circ}C$ for 15 min or pH 2.10. Therefore, the main substances responsible for the antimicrobial activity of the MY ethanol extract are believed to be stable with changing heat and pH.

• 한국치위생학회지
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• 제12권1호
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• pp.81-91
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• 2012

Objectives : By investigating antimicrobial activity of natural extracts, identifying its usefulness as antibiotic material to oral bacteria. Methods : Antimicrobial activity tests of 25 natural extracts were implemented on 6 type strains alleged to cause dental caries and 10 clinical strains isolated and identified from dental caries. Results : Among medicinal plants, Coptis japonica, Scutellaria baicalensis, Dictamnus dasycarpus showed antimicrobial activity. Among lichens, 3 methanol extracts and 6 acetone extracts showed antimicrobial activity. Minimum Inhibitory Concentration(MIC) test of Usnea aurantiacoatra KoLRI 004184, an acetone extract of lichen with the highest antimicrobial activity, on 6 type strains involved in dental caries and 10 strains isolated from dental caries resulted as follows; Actinomyces oris 1041 $12{\mu}g/ml$, for Corynebacterium durum 3151 $13{\mu}g/ml$, for Rothia dentocariosa KCTC $3204^T$ $14{\mu}g/ml$, for R. dentocariosa 911 $15{\mu}g/ml$, for R. dentocariosa 1822 $12{\mu}g/ml$, for Lacto-bacillus casei KACC $12413^T$ $12{\mu}g/ml$, for L. acidophilus KACC $12419^T$ $16{\mu}g/ml$, for L. rhamnosus 2421 $15{\mu}g/ml$, for Streptococcus mutans KCTC $3065^T$ $15{\mu}g/ml$, for S. mutans 121 $13{\mu}g/ml$, for Streptococcus oralis 2221 $18{\mu}g/ml$, for S. salivarius KCTC 5512 $14{\mu}g/ml$, for S. salivarius 122 $12{\mu}g/ml$, for S. sanguinis KCTC $3284^T$ $14{\mu}g/ml$, for S. sanguinis 912 $14{\mu}g/ml$, for Neisseria sp. KEM232 $12{\mu}g/ml$. Conclusions : Even a small amount of extract from lichen Usnea aurantiacoatra KoLRI 004184 showed very high level of antimicrobial activation against all 16 bacterial strains involved in dental caries.

• 대한한의학회지
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• 제18권1호
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• pp.169-186
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• 1997

Scutellariae Radix has been widely used as oriental herbal medicine for the treatment of bacterial infections in the respiratory or the gastrointestinal tract. In partition experiment for better understanding of herbal medicine with various solvents, baicalein or wogonin have more hydrophobic characteristics than baicalin or wogonoside. Unexpectedly, methylene chloride could extract more for baicalin or wogonoside over other active ingredients. New compound from baicalin is discovered casting frointier area on herbal medicine in the future. Application study with new molecule hydrolyzed from baicalin is on the way for better treatment of the patient against specific disease. The baicalin modified with reaction has been shown weak antibacterial activity against Streptococcus pyogenes 308A and Pseudomonas aeruginosa 1771. The minimum inhibitory concentration (MIC) of the baicalin modified compound against those strains were about $600\;{\mu}g/mL$, respectively. In vitro antitumor experiment, $EC_{50}$ of baicalin modified with reaction was more than $300\;{\mu}g/mL$ and $EC_{50}$ of baicalein was $100\;{\mu}g/mL$. Among these compounds, baicalin exhibited high level of antitumor activity. $EC_{50}$ of baicalin was less than $33.3\;{\mu}g/mL$.

• 한국동물위생학회지
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• 제40권2호
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• pp.101-105
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• 2017

The purpose of this study was to investigate prevalence and antimicrobial resistance patterns of Campylobacter spp. from duck feces in northern area of the Gyeongnam province, Korea. Samples of 121 duck feces were taken from April to December 2014 for this survey. Samples were examined by bacteria isolation and reverse transcriptase-polymerase chain reaction assay for detection of Campylobacter spp. Campylobacter were isolated in 37 samples (30.6%). Among these samples, C. jejuni and C. coli were isolated in 35 samples and 2 samples, respectively. Minimum inhibitory concentration (MIC) test is performed to investigate antimicrobial resistance patterns of Campylobacter spp. C. jejuni were resistant to ciprofloxacin (85.7%), nalidixic acid(82.9%), tetracycline (77.1%), gentamicin (57.1%), azithromycin (40.0%), clindamycin (34.3%), erythromycin (22.9%), and florfenicol (8.6%). These data support a database of pollution and antimicrobial resistance of Campylobacter spp. from duck feces and provide a basic information of reducing the secondary damage of antibiotic misuse.

• 미생물학회지
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• 제33권3호
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• pp.170-174
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• 1997

강한 항진균 활성을 나타내며, 낮은 적혈구 용혈활성을 갖는 새로운 합성 펩티드를 얻기 위하여 cecropin A(1-8)-magainin 2(1-12) 및 이들의 유사체들을 설계하고 이들을 고상법에 의하여 합성하였다. 합성 펩티드의 항진균 활성은 Trichosporon beigelii에 대한 성장억제능에 의하여 측정하였으며, 세포독성은 인간의 적혈구 세포에 대한 용혈활성에 의하여 측정하였다. 펩티드의 양쪽 친매성의 증가는 항진균활성보다는 적혈구 용혈황성에 큰 영향을 미쳤다. Cecropin A(1-8)-magainin 2(1-12)의 12번 아미노산이 Lys을 Ala으로 치환시킨 유사체 펩티드(A2)는 가장 강한 항진균활성(minimum inhibitory concentration : 2.5.$\mu$g/ml)을 나타내며 비교적 낮은 적혈구 용혈활성(200.$\mu$g/ml의 펩티드 농도에서 0.5% hemolysis를 나타냄)을 나타내었다. 따라서 A2의 펩티드는 세포독성을 갖지 않으며 강한 항진균 활성을 가지는 모델로서 유용하게 사용될 것이다.

• International Journal of Oral Biology
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• 제39권2호
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• pp.87-95
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• 2014

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, $CO_2$, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin$^{(R)}$ (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

• 대한화학회지
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• 제37권7호
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• pp.677-682
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• 1993

방출조절성 약제를 개발하기 위한 방법으로 polyacrylic acid와 polymethacrylic acid에 thionylchloride로 chlorination하여 cephalexine을 반응시켜 Polyacryloylcephalexine 과 polymethacryloylcephalexine을 합성하였다. Polyacryloylcephalexine 중합체약에 대한 최소 발육 저지 농도로서 항균력은 Micrococcus luteus ATCC 9341과 Escherichia coli ESS이 우수하고, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Klebsiella pueumouiae KCTC 1560, Escherichia coli KCTC 1039, Salmonella typhimurium KCTC 1925 균주들에 대해서도 항균성이 대체적으로 우수하였다. polymethacryloylcephalexine 중합체약에 대한 최소 발육 저지 농도는 Micrococcus luteus ATCC 9341과 Klebsiella pueumouiae KCTC 1560이 우수하고, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Escherichia coli KCTC 1039, Escherichia coli ESS, Salmonella typhimurium KCTC 1925 균주들에 대해서는 항균력이 양호하였다.