• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1116-1122
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• 2000

천연 식품보존료 개발의 일환으로 우리 나라에서 옛부터 조미료 및 향신료 등으로 널리 이용되고 초피를 가시 있는것과 없는 것으로 구분하여 이들의 잎, 과피 및 종실을 대상으로 물과 에탄올로 항균성 물질을 추출하여 수종의 병원균과 식중독균, 식품과 관련이 있는 세균 및 효모 줄 10균주들에 대하여 항균성이 있는지의 여부를 관찰하였으며, 항균성이 강한 에탄올추출물의 초소저해농도, 추출물에 함유된 항균성물질의 열안전성, pH안정성 등을 조사하였다. 초피와 민초피의 항균활서은 tkdydd된 10균주 중 젖산균과 효모를 제외한 대부분의 세균에서 잎과 과피에서 물과 에탄올추출물 모두에서 항균활성이 나타났으나 종실에서는 항균활성을 보이지 않았다. 초피 에탄올추출물의 최소저해농도는 Bacillus cereus 균주가 0.25mg/mL로 가장 낮게 나타났으며, 젖산균과 효모에서는 항균활성 물질은 121$^{\circ}C$에서 15분간 가열한 후에도 활성이 유지되었으며, pH의 변화에도 영향을 받지 않았다.

• Toxicological Research
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• v.21 no.1
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• pp.39-43
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• 2005

The present study was carried out to investigate the antibacterial activity against Staphylococcus aureus with antibiotic-resistance in vitro and the skin irritation in rabbits with surfactin produced by Bacillus subtilus Complex BC1212. The antibacterial activities of selected antimicrobial agents (surfactin, amoxacillin, colistin, norfloxacin and streptomycin) were evaluated by using the broth microdilution method. As the results, the minimum inhibitory concentration (MIC) of the surfactin was less than 15.6 ㎍/ml. In the skin irritation test, two out of 4 rabbits showed very slight edema at 24 h after the administration of surfactin, and then recovered at 72 h. The change of body weight was normal during the skin irritation test. The primary irritation index in accordance with the Draize evaluation of topical reaction was calculated to be '0.125', which meant not irritating. Based on these results, it could be concluded that the test agent, surfactin, was a non-irritant. We could also think that the surfactin may be useful for the treatment of S. aureus infections such as bovine mastitis.

• Journal of Life Science
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• v.8 no.6
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• pp.648-653
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• 1998

The development of natural food preservatives instead of chemical synthetic food preservatives is world wide inte-rest. Authors already investigated that cinnamon bark extract revealed antimicrobial activity against general spoilage microorganisms of food especially its acitivity was stronger against molds than against bacteria. In this paper, authors examined the mirobial flora from the spoiled fish meat paste products and also checked the possibility of cinnamon bark extract food preservative for prolong the shelf life of the fish paste product and breads. The predominat bacteria was Bacillus sp. as about 98% of the total microorganisms isolated from unpacked or packed spoiled fish meat paste products. While molds and yeast are not detected from the vacuum packed products. The MIC(minimum inhibitory concentration) of cinnamon bark extract against the isolated spoilage bacteria and molds was 160~640$\mu\textrm{g}$/$m\ell$ and 40~80$\mu\textrm{g}$/$m\ell$, respectively. When the diluted cinnamon bark extract (the extract : ethanol=1 : 3) was sprayed on the surface of fried fish meat paste product, molds growth was delayed by 2 days at room temperature. The shelf lifes of sandwich and glutinousrice bread which surface sprayed with the diluted extract(1 : 1) was extended by 5 and 7 days, respectively.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.889-895
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• 2006

To investigate the antibiotic-resistant patterns and the gene types of extended-spectrum $\beta$-lactamase (ESBL)-producing Klebsiella pneumoniae, we collected 226 Klebsiella pneumoniae strains from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005, The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram-negative susceptibility (GNS) cards of Vitek (Vitek system, Hazelwood Inc., MO, U.S.A.). Of the 226 K, pneumoniae isolates, 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. TEM (Temoniera) type, SHV (sulfhydryl variable) type, and CTX-M (cefotaxime) type genes were detected by polymerase chain reaction. All 65 K. pneumoniae strains were resistant to ampicillin, cefazolin, cefepime, ceftriaxone, and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole, and 43.0% to gentamicin. TEM-type ESBLs (TEM-1 type, -52 type) were found in 64.6% (42 of 65) of the isolates, SHV-type ESBLs (SHV-2a type, -12 type, -28 type) in 70.7% (46 of 65) of isolates, and CTX-M-type ESBLS (CTX-M-15 type) in 45% (29 of 65) of isolates. Of the 65 ESBL-producing K. pneumoniae strains, two strains were found to harbor blaSHV-28, which were detected in Korea for the first time. Therefore, more investigation and research on SHV-28 are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosporin antibiotics.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.461-468
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• 2016

In recent years, various naturally occurring defence peptides such as plectasin have attracted considerable research interest because they could serve as alternatives to antibiotics. However, the production of plectasin from natural microorganisms is still not commercially feasible because of its low expression levels and weak stability. A tandemly arrayed plectasin gene (1,002 bp) from Pseudoplectania nigrella was generated using the isoschizomer construction method, and was inserted into the pPICZαA vector and expressed in Pichia pastoris. The selected P. pastoris strain yielded 143 μg/ml recombinant plectasin (Ple) under the control of the methanol-inducible alcohol oxidase 1 (AOX1) promoter. Ple was estimated by SDS-PAGE to be 41 kDa. In vitro studies have shown that Ple efficiently inhibited the growth of several gram-positive bacteria such as Streptococcus suis and Staphylococcus aureus. S. suis is the most sensitive bacterial species to Ple, with a minimum inhibitory concentration (MIC) of 4 μg/ml. Importantly, Ple exhibited resistance to pepsin but it was quite sensitive to trypsin and maintained antimicrobial activity over a wide pH range (pH 2.0 to 10.0). P. pastoris offers an attractive system for the cost-effective production of Ple. The antimicrobial activity of Ple suggested that it could be a potential alternative to antibiotics against S. suis and S. aureus infections.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.1
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• pp.18-22
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• 2014

The antibacterial activities of methanol extracts of 19 commercial herbal medicines were measured against the fish pathogens Vibrio ichthyoenteri and Streptococcus iniae, which cause several fish diseases. Rhus javanica showed the strongest antibacterial activity against V. ichthyoenteri and S. iniae. The methanol extract of R. javanica was extracted further using several organic solvents with different polarities. The extract from the ethyl acetate fraction showed strong activity against both fish pathogens. The minimum inhibitory concentration (MIC) of the R. javanica extract was $32{\mu}g/mL$ for V. ichthyoenteri and $128{\mu}g/mL$ for S. iniae. Further purification and isolation of the active compound (s) responsible for these activities and further study of the synergistic effect using combinations of antibiotics against pathogenic bacteria are needed.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.707-710
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• 2005

The antimicrobial activities of extracts from some of natural products and bacteriocins produced from lactic acid bacteria such as L. mesenteroides, L. citreum and P. pentosaceus have been investigated with using disc diffusion assay, challenge method and minimum inhibitory concentration method. The bacteriocin substances produced from L. mesenteroides, L. citreum and P, pentosaceus have shown strong antimicrobial activities against E. coli, S. aureus, P. aerugionosa, and B. subtillis while the extracts from phenonip and sandal wood have shown strong antimicrobial activities only against C. albicans. The bacteriocins produced from L. mesenteroides, L. citreum and P. pentosaceus could be a promising preservatives for cosmetics, pharmaceutical products and foods in future.

• Biomedical Science Letters
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• v.12 no.3
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• pp.267-274
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• 2006

Klebsiella pneumoniae is the leading cause of nasocomial infection and the most commonly isolated from clinical specimens. $Extended-spectrum-{\beta}-lactamase$ (ESBL) producing K. pneumoniae infection was associated with a significantly longer duration of hospital stay and greater hospital charges. The purpose of this study is to investigate the antibiotic resistant patterns and the DNA fingerprint types of extended-spectrum ${\beta}-lactamase$ (ESBL) producing K. pneumoniae. 223K. pneumoniae strains were collected from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005. The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram negative susceptibility (GNS) cards of VITEK (Vitek system, Hazelwood Inc., MO). Random amplified polymorphic DNA method was used to detect DNA fingerprint of the organisms. Of the 226 K. pneumoniae isolates 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. All the 65K. pneumoniae strains were resistant cefazolin, cefepime, ceftriaxone and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole and 43.0% to gentamicin. The RAPD patterns were distincted as 10 types by three random 10-mer primers (208, 272, 277). Among ten type patterns, three types (Ic, IIb, IIIe) were remarkably represented at patient of internal department, nerve surgery department, general surgery department, and neonatal room. These results indicate that RAPD can be useful for DNA of strains typing in the epidemiological investigations. Therefore more investigation are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosphorin antibiotics.

• The Plant Pathology Journal
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• v.19 no.3
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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.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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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.