• 한국식품위생안전성학회지
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• 제11권4호
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• pp.307-314
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• 1996

The European Economic Community four plate test(EEC 4-plate test, FPT, EU) has been used for monitoring antimicrobial drug residues in meat by Local Veterinary Service Center in Korea. This study was performed to evaluate sensitivity and group specificity of some antimicrobial drugs in FPT and to compare FPT with Charm II test. The minimal detectable levels of targeted antimicrobial drugs tested with standard solutions were 0.025∼1.0 ppm for 7 beta-lactams, 0.5∼1.0 ppm for 4 aminoglycosides, 0.05∼0.5 ppm for 5 macrolides, 0.05∼0.25 ppm for 3 tetracyclines and 0.25&1.0 ppm for 6 sulfonamides. In comparison of FPT and Charm II test, the results of FPT were not accord with those of Charm II test having the group specificity of seven families of antimicrobial drugs in meat samples except some families like tetracyclines.

• 대한수의학회지
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• 제17권1호
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• pp.13-16
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• 1977

In order to know the current status of sensitivity of Corynebacterium renale to some antimicrobial agents of current use, the sensitivity of 37 strains isolated from urine and vaginal cavity of healthy Korean native cattle and dairy cattle was studied by agar plate dilution method, and their sensitivity according to serological types was compared. The antimicrobial agents tested were streptomycin (SM), erythromycin (EM), oxytetracycline (OT), penicillin G (PC), gentamycin (GM), kanamycin (KM), ampicillin (AP), leucomycin (LM), chloramphenicol (CM), colistin (CL), sulfadimethoxine (SDM) and sulfadiazine (SDZ). Most strains were highly sensitive to PC, GM, AP, LM and KM, and moderate to CM and OT, but resistant to SM, EM, CL, SDM and SDZ. Serological type II was more sensitive to EM, SDM and SDZ than type I and II, but more resistant to SM.

• 한국콘텐츠학회논문지
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• 제9권2호
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• pp.339-349
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• 2009

마늘은 오랫동안 그 가치가 높이 평가되고 있으며 약용, 항균 및 살균효과적인 특성으로 인해 실제로 사용되어오고 있다. 본 연구는 마늘추출물의 천연식품보존제 개발가능성을 알아보기 위해 수행되어졌으며 신선한 마늘추출물과 이를 증류수로 희석한 마늘추출물들을 사용하여 6종의 식중독균 즉, S. aureus, E. coli, S. typhimurium, V. parahemolyticus, B. subtilis, L. monocytogenes들에 대한 감수성검사를 실시하였고 그 결과를 그람양성균 치료에 사용되는 Vancomycin과 그람음성균 치료에 사용되는 Imipenem을 대조로하여 이들 균주에 대한 항균력과 비교하였다. 마늘추출물에서 6균주 모두에 대해 강한 감수성을 보이거나 혹은 중등도의 감수성을 보였는데 V. parahemolyticus만은 마늘추출물의 원액에서만 항균력이 나타났고 희석한 농도에서는 항균력이 없었다.

• 한국임상수의학회지
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• 제21권2호
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• pp.129-132
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• 2004

Causative agents of mastitis were isolated from glandular tissues of 101 culled Holstein cow udders and tested with antimicrobials by standardized disc diffusion method. Pathogens most commonly isolated were coagulase-negative staphylococci (43.9%) and streptococci (21.4%). Most of the udders (88.5%) showed mixed infections with more than two species of bacteria. Antimicrobial sensitivity tests revealed that 90.0% and 84.5% of the isolated organisms were susceptible to amoxicillin and gentamicin, while most organisms were resistant to erythromycin. Coliforms were resistant to ampicillin, cephalothin, cefazolin, erythromycin, kanamycin, neomycin, penicillin and tetracycline and streptococci to erythromycin, kanamycin, neomycin, trimethoprim/sulfamethoxazole and tetracycline.

• Advances in materials Research
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• 제11권3호
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• The Plant Pathology Journal
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• 제30권3호
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• pp.245-253
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• 2014

Antimicrobial peptides (AMPs) are small but effective cationic peptides with variable length. In previous study, four hexapeptides were identified that showed antimicrobial activities against various phytopathogenic bacteria. KCM21, the most effective antimicrobial peptide, was selected for further analysis to understand its modes of action by monitoring inhibitory effects of various cations, time-dependent antimicrobial kinetics, and observing cell disruption by electron microscopy. The effects of KCM21 on Gram-negative strain, Pseudomonas syringae pv. tomato DC3000 and Gram-positive strain, Clavibacter michiganensis subsp. michiganensis were compared. Treatment with divalent cations such as $Ca^{2+}$ and $Mg^{2+}$ inhibited the bactericidal activities of KCM21 significantly against P. syringae pv. tomato DC3000. The bactericidal kinetic study showed that KCM21 killed both bacteria rapidly and the process was faster against C. michiganensis subsp. michiganensis. The electron microscopic analysis revealed that KCM21 induced the formation of micelles and blebs on the surface of P. syringae pv. tomato DC3000 cells, while it caused cell rupture against C. michiganensis subsp. michiganensis cells. The outer membrane alteration and higher sensitivity to $Ca^{2+}$ suggest that KCM21 interact with the outer membrane of P. syringae pv. tomato DC3000 cells during the process of killing, but not with C. michiganensis subsp. michiganensis cells that lack outer membrane. Considering that both strains had similar sensitivity to KCM21 in LB medium, outer membrane could not be the main target of KCM21, instead common compartments such as cytoplasmic membrane or internal macromolecules might be a possible target(s) of KCM21.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2818-2824
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• 2014

Trp residue is considered as one of the important constituents in antimicrobial peptides (AMPs) as it presence secured good activities in many cases. However, it is preferable to be changed because of their sensitivity towards light. We have synthesized the short Trp-rich AMP Pac-525 and its analogues to investigate the possibility of His(chx) as possible replacement analogue for Trp in AMPs. Based on the assay result of the antibacterial activity including anti-MRSA activity, His(chx) is considered as good candidate for the Trp replacement. Through these study, we found that His(chx) had several merits to design therapeutic antimicrobial agents compare to Trp in terms of i) increasing antibacterial activity without hemolytic activity, ii) successful in designing the short peptide (only four residues), iii) having anti-MRSA activity, iv) overcoming the light sensitivity. Furthermore, transmission electron microscopy (TEM) and dye leakage experiments suggested that P11 and P16 containing His(chx) kill bacteria via forming pore/ion channels on bacterial cell membranes.

• 한국축산식품학회지
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• 제36권4호
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• pp.487-493
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• 2016

The antimicrobial activity of bovine lactoferrin hydrolysates (bLFH) was measured against Pseudomonas strains (P. syringae and P. fluorescens) in vitro. To compare susceptibility to bLFH, minimal inhibitory concentration (MIC) values were determined using chemiluminescence assays and paper disc plate assays. Antimicrobial effect against P. fluorescens was not observed by either assay, suggesting that bLFH did not exhibit antimicrobial activity against P. fluorescens. However, a significant inhibition of P. syringae growth was observed in the presence of bLFH. The addition of bLFH in liquid or solid medium inhibited growth of P. syringae in a dose-dependent manner. Furthermore, a bLFH peptide with antimicrobial activity toward P. syringae was isolated and identified. The N-terminal amino acid sequences of thus obtained antimicrobial bLFH peptides were analyzed by a protein sequencer and were found to be Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala and Phe-Lys-Cys-Arg-Arg-Trp-Gln-Trp-Arg-Met. The latter peptide sequence is known to be characteristic of lactoferricin. Therefore, in the present study, we identified a new antimicrobial peptide against P. syringae, present within the N-terminus and possessing the amino acid sequence of Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala.

• Archives of Plastic Surgery
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• 제33권3호
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• pp.330-334
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• 2006

Polymicrobial nature of diabetic foot infection has been well documented in the literature. Initial antibiotic therapy of diabetic foot infection is usually empiric until reliable culture data is shown. This study was carried out to determine the common bacteriological flora of diabetic foot infection and antimicrobial sensitivity pattern in order to enhance possible empiric treatment. The specimens were obtained from wounds of 207 cases of diabetic foot ulcer, and the bacteriological isolation, and antimicrobial susceptibility tests of the isolates were carried out by standard microbiological methods. Staphylococcus aureus was the most common isolate, with 46.2% of recover rate among total bacterial isolated cases. Among gram-negative organisms, Pseudomonas aeruginosa was most common. Gram-positive organisms showed significant susceptibility to clindamycin, trimethoprim/sulfamethoxazole, and levofloxacin, besides vancomycin. Cefoperazone, piperacillin/tazobactam, and amikacin in addition to imipenem were most effective agents compared to gram-negative organisms. Diabetic foot infection requires use of combined antimicrobial therapy for initial management. Our results indicate that the most effective antibiotic combination for diabetic foot infection of Korean patients is clindamycin plus cefoperazone.

• Asian-Australasian Journal of Animal Sciences
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• 제28권5호
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• pp.620-631
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• 2015

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.