• Title/Summary/Keyword: MIC value

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A Study on the Antibacterial Activity of Chitosan on the MRSA by the Shake Flask Method and Modified Shake Flask Method (Shake Flask Method와 개량 Shake Flask Method에 의한 키토산의 MRSA 향균성 평가)

  • Choi, Jeong-Im;Jeon, Dong-Won
    • Fashion & Textile Research Journal
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    • v.5 no.1
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    • pp.64-70
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    • 2003
  • Water-insoluble chitosan with molecular weight of 2,000,000, 580,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were prepared to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus (MRSA). As experimental method, the Shake Flask Method (SFM) and Modified Shake Flask Method (MSFM) were applicated. The anti-microbial activity of chitosan/acetic acid aqueous solution is consistent irrespective of Mw of chitosan. MIC value of SFM measurement was 0.2 ppm, and MIC value of modified SFM measurement was 25 ppm. But MIC value of chitosan/acetic add solution and chitosan treated cotton filter paper was equally 5 ppm. The antibacterial activities of chitosan were different in different test measurements employed. The antibacterial activities of chitosan/acetic acid solution and chitosan treated cotton filter paper were also different. Therefore, it needs to be pointed out that the test measurements of anti-microbial activity have some problems.

Distribution of resistance genes against lincomycin of pathogenic bacteria isolated from cultured olive flounder (Paralichthys olivaceus) (양식 넙치에서 분리한 어병세균의 lincomycin에 대한 내성 유전자의 분포)

  • Kim, Ye Ji;Jun, Lyu Jin;Lee, Young Juhn;Ko, Ye Jin;Han, So Ri;Kim, Sung Hyun;Jeong, Joon Bum
    • Journal of fish pathology
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    • v.35 no.1
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    • pp.47-56
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    • 2022
  • Lincomycin as one of the lincosamides antibiotics have been mainly used in human and livestock fields, but have not been used in aquaculture. In this study, the distribution of minimum inhibitory concentration (MIC) values against lincomycin and the detection of the macrolide-lincosamide-streptogramin (MLS) resistance gene were confirmed in bacterial pathogens isolated from cultured olive flounder (Paralichthys olivaceus). Of the 107 strains isolated from Jeju, 36 strains of Gram-positive bacteria and 71 strains of Gram-negative bacteria were identified. Most of Streptococcus spp. was found to have a MIC value of less than or equal to 0.5 ㎍/mL, and Edwardsiella piscicida was found to have a MIC value higher than 1,024 ㎍/mL. V. harveyi and V. alginolyticus mostly showed MIC values of 256 ㎍/mL, but V. scophthalmi displayed values of 8~64 ㎍/mL. In the detection of MLS resistance gene, erm(B) was detected in 9 strains of Streptococcus spp., and erm(A) was confirmed in one strain.

Antifungal Susceptibility Testing for the Dermatophytes Isolated from Dogs and Cats (개와 고양이에서 분리한 피부사상균에 대한 항진균제의 감수성시험)

  • Shin, Jae-Eun;Sung, Choong-Hyun;Kim, Doo
    • Journal of Veterinary Clinics
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    • v.18 no.1
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    • pp.1-6
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    • 2001
  • The aim of this study was to determine optimal therapeutic dose of antifungal agents for dermatophytes. Forty nine dermatophytes were isolated form dogs and cats showing skin lesions and were tested for their in vitro susceptibility to nystatin, griseofulvin, terbinafine, ketoconazole and fluconazole by broth microdilution test. Terbinafine showed the lowest MIC value among the antifungal agents tested, and MIC values ranged from 0.002 to 0.016 $\mu\textrm{g}$/ml. Fluconazole showed the highest MIC values among the antifungal agents tested, and MIC values ranged from 32 to 512 $\mu\textrm{g}$/ml. MIC values of nystatin, griseofulvin and ketoconazole ranged from 1.12 to 4.48 $\mu\textrm{g}$/ml, 0.5 to 4.0 $\mu\textrm{g}$/ml, and 1.6 to 12.8 $\mu\textrm{g}$/ml, resistant to griseofulvin, and that antifungal susceptibility test was needed to determine optimal therapeutic dose of antifungal agents for each dermatophyte.

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Resistance of Some Metal Ions on Growth of Serratia marcescens Strain P (Serratia marcescens Strain P 성장에 미치는 중금속 내성)

  • 유관희;이호용
    • Microbiology and Biotechnology Letters
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    • v.20 no.6
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    • pp.693-698
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    • 1992
  • The resistant effect of several heavy metal ions to Serratia marcescens strain P was studied by the method of minimal inhibitory concentration(MIC), and testing for their metal biosorption. S. marcescens strain P showed a good survival in the presence of high concentrations of some metal ions, namely cadmium, lead, iron, magnesium, and manganese. Copper had the most inhibitory effect among tested. The MIC value was ranged from 0.79 to 1.58 mM. Cells of S. marcescens strain P exhibit an abnormally long lag phase when incubated in high concentrations of zinc and cadmium. Pigment production was reduced by zinc and cadmium, but enhanced by lead and iron. S. marcescens strain P was resistant to ampicillin, tetracycline, cefamandole and chloramphenicol with minimal inhibitory concentration of 128 $\mu$g/ml, 32 $\mu$g/ml, 256 $\mu$g/ml, and 8 $\mu$g/ml, respectively. The kinetics study of biosorptive uptake by S. marcescens strain P revealed that 16.59% of cadmium and 35.38% of lead were eliminated from the media.

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A Study on the Antimicrobial Activity and Preservative Effect of Thiamine Dilauryl Sulfate in Cosmetics (티아민 디라우릴 황산염이 함유된 화장품의 항균활성 및 방부효과에 관한 연구)

  • Lee, Dong-Kyu;Kim, Hyuk-Soo;Cho, Kyung-Whan
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.3
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    • pp.212-218
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    • 2005
  • Most of cosmetics are emulsion products that contain the source of nutrition vegetable oil, mineral oil, natural extract and carbohydrate etc. There are many possibilities to be contaminated by microbials. We investigated the effect of antimicrobial and minimum inhibitory concentration(MIC) with thiamine dilauryl sulfate(TDS), which was prepared to use cosmetic lotion formulation. Staphylococcus aureus(S. aureus) and Escherichia col(E. coli) were used as test organism. MIC value of TDS was determined aganist microorganism for the growth inhibition by concentration of TDS. From the MIC results, antimicrobial effect of TDS was generally more effective to gram positive than gram negative. Antimicrobial effect with pH value against some microorganism appeared in the following order : pH 5 > pH 6 > pH 7. It showed strong antimicrobial activities against S. aureus, and weak antimicrobial activities against E. coli. If it was possible to determine the formulations with TDS, it would be effective to reduce the artificial preservatives.

A Study on the Antimicrobial Finishing of Artificial Suede by Allylamine Copolymers (Allylamine계 항균제를 이용한 인조스웨드 직물의 항균코팅에 관한 연구)

  • 김윤정;이종우;윤남식
    • Textile Coloration and Finishing
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    • v.12 no.1
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    • pp.61-67
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    • 2000
  • This study was carried out to develope antimicrobial artificial suede by coating with water soluble polyurethane resin and the copolymer of N,N'-dialkyl-N,N'-dialkyl ammonium chloride (DADAAC) and acrylamide as a antimicrobial additve. The copolymer of DADAAC and acrylamide was synthesized by free radical initiation and intra-intermolecular propagation, and the prepared copolymers had sufficient compatibility with water soluble polyurethane resin. The MIC values of the prepared copolymers and antimicrobial characteristics of the artificial suede coated by polyurethane were evaluated. With the increase in the proportion of DADAAC, which is antimicrobially active part in the DADAAC/acrylamide copolymers, the MIC value becomes lower. The MIC value of DADAAC-AA (1 : 1) copolymer is below 30 ppm against S. aureus, and below 90 ppm against K pneumoniae. The artificial suede coated by water soluble polyurethane resin with 1.0% owl concentration of DADAAC/acrylamide copolymer has good antimicrobial fastness as to show colony reduction of above 90% and 80% against S. aureus and K. pneumoniae respectively in the shake flask test after 10 times of washing, and above 95% and 85% after 10 times of dry-cleaning. The elastic recovery of coated suede fabric is not affected up to 1.0% owf concentration of DADAAC-AA copolymer in the polyurethane coating.

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전해 알칼리수의 마늘 부패균에 대한 항균력 검정

  • Gang, Seon-Cheol;Seo, Hae-Jeong;Choe, Nan-Hui
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.694-696
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    • 2003
  • This study was conducted to improve circulation system and the storage of garlic against the spoiling microorganisms during the storage. To fulfill this objective, the isolation and identification of spoiling microorganisms from horticultural products were performed at the first step. Antimicrobical activity of electrolyzed alkaline water (EAW) was tested against the spoiling microorganisms and MIC(minimun inhibitory concentration) was determined. As a result, it showed the formidable MIC value at near 2.0%(v/v) against the spoiling microorganisms.

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High Expression of Water-Soluble Recombinant Antigenic Domains of Toxoplasma gondii Secretory Organelles

  • Yang, Zhaoshou;Ahn, Hye-Jin;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.52 no.4
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    • pp.367-376
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    • 2014
  • Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with $GRA2_{25-105}$, $GRA3_{39-138}$, $ROP2_{324-561}$, and $MIC2_{1-284}$ domains had respectively higher value of IgG avidity. The $rGST-GRA2_{25-105}$ and $rGST-GRA3_{39-138}$ were soluble, while $rGST-ROP2_{324-561}$ and $rGST-MIC2_{1-284}$ were not. $GRA2_{31-71}$, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The $rGST-GRA2_{31-71}-ROP2_{324-561}$, a chimeric protein, appeared to be soluble. Moreover, $rGST-GRA2_{31-71}-MIC2_{1-284}$ was also soluble and had higher IgG avidity comparing to $rGST-MIC2_{1-284}$. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.

A Novel MPPT Control of PV MIC System Considering the Shaded Effect (그림자 영향을 고려한 PV MIC 시스템의 새로운 MPPT 제어)

  • Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.5
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    • pp.21-33
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    • 2012
  • This paper presents the new maximum power point tracking(MPPT) control of the photovoltaic(PV) module integrated converter(MIC) system considering the shadow influence. The output characteristics of the solar cell is a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. Particularly, MIC system is very sensitive to the shadow influence because the capacity is very small. In order to increase an output and efficiency of the solar power generation, the maximum power point(MPP) obeying control are necessary. Conventional perturbation and observation(PO) and Incremental conductance(IC) are the method finding MPP by the continued self-excitation vibration. The MPPT control is unable to be performed by rapid output change affected by the shadow. To solve this problem, the new control algorithm of the multi-level in which the step value changes by output change is presented. In case there are the solar radiation, a temperature and shadow influence, the presented algorithm treats and compares the conventional control algorithm and output error. In addition, the validity of the algorithm is proved. through the output error response characteristics.

Anti-Helicobacter pylori Compounds from Polygonum cuspidatum

  • Khalil, Atif Ali Khan;Park, Woo Sung;Kim, Hye Jin;Akter, Kazi Marjahan;Ahn, Mi-Jeong
    • Natural Product Sciences
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    • v.22 no.3
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    • pp.220-224
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    • 2016
  • Anti-Helicobacter pylori activity guided fractionation led to the isolation of five anthraquinones, two stilbenes and one naphthoquinone from the EtOAc fraction of Polygonum cuspidatum, using silica gel column chromatography, Sephadex-LH20, MPLC and recrystallization. The chemical structures were identified to be physcion (1), emodin (2), anthraglycoside B (3), trans-resveratrol (4), anthraglycoside A (5), polydatin (6), 2-methoxy-6-acetyl-7-methyljuglone (7) and citreorosein (8) by UV, $^1H$-NMR, $^{13}C$-NMR and mass spectrometry. Anti-Helicobacter pylori activity including MIC values of each compound was evaluated. All of the isolates exhibited anti-H. pylori activity of which MIC values were lower than that of a positive control, quercetin. Compounds 2 and 7 showed potent growth inhibitory activity. Especially, a naphthoquinone, compound 7 displayed most potent antibacterial activity with $MIC_{50}$ value of $0.30{\mu}M$ and $MIC_{90}$ value of $0.39{\mu}M$. Although anti-H. pylori activity of this plant was previously reported, this is the first report on that of compounds isolated from this species. From these findings, P. cuspidatum roots or its isolates may be useful for H. pylori infection and further study is needed to elucidate mechanism of action.