• Title/Summary/Keyword: MIC

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Analysis of Antibiotic Resistant Patterns in Conjugant and Transformant of Three ESBL gene Harboring Klebsiella pneumoniae (세 가지의 ESBL 유전자를 가지고 있는 Klebsiella pneumoniae의 유전자접합체와 헝질전환체의 항생제내성분석)

  • Kim, Yun-Tae
    • Journal of Life Science
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    • v.17 no.10
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    • pp.1426-1433
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    • 2007
  • To investigate the antibiotic resistant patterns of the bacteria producing ESBL, we isolated one organism of Klebsiella pneumoniae from a clinical laboratory in Busan. The organism that produces ESBL gene was detected by double disk synergy test and the presence of three ESBL genes (TEM-1, SHV-12, CTX-M-15) was confirmed by polymerase chain reaction and DNA sequencing analysis. To analyse the characteristics of three ESBL genes, we performed transconjugation, transformation and cloning experiment with the organism. The MIC of Klebsiella pneumoniae was revealed that ceftazidime, cefotaxime and ceftriaxone were $256\;{\mu}g/ml,\;128\;{\mu}g/ml\;and\;128\;{\mu}g/ml$ respectively. The MIC of conjugant (E. coli $RG176^{Na(r)}$) af was revealed that ceftazidime, cefotaxime and ceftriaxone were $256\;{\mu}g/ml,\;64\;{\mu}g/ml\;and\;128\;{\mu}g/ml$ respectively. The MIC of transformant (E. cofi $DH5{\alpha}$) was revealed that ceftazidime, cefotaxime and ceftriaxone were $128\;{\mu}g/ml,\;32\;{\mu}g/ml,\;and\;32\;{\mu}g/ml$ respectively, The MIC of cloned organism of SHV-12 gene (E. coli $DH5{\alpha}$) was revealed that ceftazidime, cefotaxime and ceftriaxone were $128\;{\mu}g/ml,\;8\;{\mu}g/ml,\;and\;32\;{\mu}g/ml$ respectively. The results indicated that MIC of conjugant was higher than MIC of transformant and also SHV-12 gene were not resistant against cefotaxime antibiotic.

Antibacterial Mechanism and Salad Washing Effect of Bitter Orange Extract Against Salmonella Typhimurium (광귤 추출물의 Salmonella Typhimurium에 대한 항균 메커니즘 및 샐러드 세척 효과)

  • Yoon-Mi Ji;Ji-Yun Bae;Chung-Hwan Kim;Se-Wook OH
    • Journal of Food Hygiene and Safety
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    • v.39 no.3
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    • pp.273-280
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    • 2024
  • In this study, the antibacterial activity and mechanisms of bitter orange extract, a natural antibacterial agent, were investigated, with a focus on its potential application in washing water for controlling Salmonella Typhimurium contamination of salad, a ready-to-eat food. The minimum inhibitory concentration (MIC) of bitter orange extract against S. Typhimurium was determined using the broth dilution method. Subsequently, S. Typhimurium was exposed to various concentrations of bitter orange extract (1/16 MIC-2 MIC) and growth curves were measured. Following treatment with bitter orange extract, we investigated its antibacterial mechanism by measuring intracellular reactive oxygen species (ROS) levels, alterations in membrane potential and integrity, and nucleic acid leakage in S. Typhimurium. Additionally, salads artificially contaminated with S. Typhimurium were treated with different concentrations of bitter orange extract using the dipping method for various durations to assess the reduction effect. The MIC of bitter orange extract against S. Typhimurium was 195.313 mg/L, and bacterial growth was completely inhibited at a concentration of 1 MIC. Furthermore, an increase in bitter orange extract concentration correlated with elevated intracellular ROS levels, membrane potential disruption, membrane damage, and nucleic acid release. Importantly, salads treated with bitter orange extract exhibited a significant reduction in S. Typhimurium counts compared to the control, and prolonged treatment times resulted in further reductions in bacterial counts. Bitter orange extract was more effective than sodium hypochlorite and can be used as a safer salad wash. These findings indicate the potential treatment of salads to prevent foodborne illnesses.

Inactivation of Escherichia coli O157:H7, Salmonella and Listeria monocytogenes by Organic Acid (유기산이 Escherichia coli O157:H7, Salmonella 및 Listeria monocytogenes의 증식에 미치는 영향)

  • Jang, Jae-Seon;Lee, Hye-Jeong;Oh, Bo-Young;Lee, Jea-Mann;Go, Jong-Myeong;Kim, Yong-Hee
    • Journal of Environmental Health Sciences
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    • v.33 no.5
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    • pp.403-407
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    • 2007
  • The inhibitory effect of the food processing agent on growth of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes was performed with organic acid, and combination of citric acid, acetic acid, propionic acid and vanillic acid. The minimun inhibitory concentration(MIC) of propionic acid was 5,000 ppm in E. coli O157:H7, 2,500 ppm in Salmonella Enteritidis and Listeria monocytogenes. MIC of citric acid was 10,000 ppm in E. coli O157:H7 and Salmonella Enteritidis, 2,500 ppm in Listeria monocytogenes. MIC of acetic acid was 2,500ppm, while in vanillic acid was 5,000 ppm in Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes. MIC of combined organc acid in E. coli O157:H7 were 2,500ppm in PC, 1,250 ppm in PA, PV, CA, CV and AV. MIC of combined organc acid in Salmonella Enteritidis were 2,500 ppm in PC, PA, PV, CA, and CV, 1,250 ppm in AV. MIC of combined organc acid in Listeria monocytogenes were 1,250 ppm in all treatment group. MIC of combined treatment of three organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes were 1,250 ppm in PCA, PCV, PAV and CAV. The inhibitory effect of organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes could be confirmed from the result of this experiment. Therefore, it was expected that the food process would increase or maintain by using organic acid.

Antifungal Activity of 5 Antifungal Agents and Granitic Powder on Microsporum canis (Microsporum canis에 대한 5가지 항진균제와 맥반석 가루의 항진균 효과)

  • Kang Tae-hyung;Lee Jeong-chi;Won Young-ho;Oh Seok-il;Lee Chung-gil;Lee Chai-yong
    • Journal of Veterinary Clinics
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    • v.22 no.4
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    • pp.371-376
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    • 2005
  • The aim of this study was to determine tile inhibitory effect of granitic powder against Microsporum canis. Fourteen strains of M. canis isolated from dgs and cats with fungal dermatitis and two strains isolated from humans were used in this study. The in vitro antifungal activities of granitic powder and 5 commercialized antifungal agents (terbinafine, itraconazole, ketoconazole, griseofulvin and fluconazole) were compared. The antifungal effect was measured by the broth microdilution method and was expressed as the minimal inhibitory concentration (MIC). The MIC value of the granitic powder was ranged from 31.3 to 250mg/ml. Terbinafine showed the lowest MIC value among the 5 commercial antifungal agents $(0.0078-0.125{\mu}g/ml)$, while fluconazole showed the highest MIC values $(125-1,000{\mu}g/ml)$. The MIC range of itraconazole, griseofuvin and ketoconazole were $0.125-0.5{\mu}g/ml\;0.625-5{\mu}g/ml$ and $10-40{\mu}g/ml$ respectively. The Geometric mean(GM) MIC values of terbinafine and ketoconazole against M. canis isolated from human were $0.0078{\mu}g/ml\;and\;10{\mu}g/ml$, respectively, while the GM MIC values of these agents against M. canis isolated from animals were $0.063{\mu}g/ml\;and\;31.4{\mu}g/ml$, respectively. Other antifungal agents did not show any significant differences in antifungal activity against M. canis of animal or human origin. Although granitic powder was shown to have antifungal activity, it was much lower than that of the 5 commercialized antifungal agents.

Antifungal Susceptibility of Microsporum canis isolated from canine dermatophytosis (개 피부병 유래의 Microsporum canis의 항진균제 감수성)

  • Han, Ki-ok;Choi, Won-pil
    • Korean Journal of Veterinary Research
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    • v.41 no.2
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    • pp.173-176
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    • 2001
  • The present study was conducted to examine the drug susceptibility of 57 strains of Microsporum canis isolated from dogs with dermatitis in Taegu, 1999. Antifungal susceptibility test was performed by the microdilution method, using 7 antifungal drugs as follows: itraconazole(I), terbinafine(T), ketoconazole(K), griseofulvin(G), amphotericin B(A), flucytosine(5-Fc)(F), tolnaftate(To). All tester strains of M canis were highly susceptible to T, I, K and To(geometric mean $MICs{\leq}0.007{\sim}0.155{\mu}g/ml$), while those were lowly susceptible to G, A and F(geometric mean MICs $0.285{\sim}26.430{\mu}g/ml$).

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Effect of Bacteria in Soil on Microbiologically Influenced Corrosion Behavior of Underground X65 Pipeline (토양 속 박테리아가 지하매설 X65 배관의 미생물 부식 거동에 미치는 영향)

  • Choe, Byung Hak;Han, Sung Hee;Kim, Dae Hyun;Kim, Woosik;Kim, Cheolman;Choi, Kwang Su
    • Korean Journal of Materials Research
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    • v.32 no.3
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    • pp.168-179
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    • 2022
  • Microbiologically Influenced Corrosion (MIC) occurring in underground buried pipes of API 5L X65 steel was investigated. MIC is a corrosion phenomenon caused by microorganisms in soil; it affects steel materials in wet atmosphere. The microstructure and mechanical properties resulting from MIC were analyzed by OM, SEM/EDS, and mapping. Corrosion of pipe cross section was composed of ① surface film, ② iron oxide, and ③ surface/internal microbial corrosive by-product similar to surface corrosion pattern. The surface film is an area where concentrations of C/O components are on average 65 %/16 %; the main components of Fe Oxide were measured and found to be 48Fe-42O. The MIC area is divided into surface and inner areas, where high concentrations of N of 6 %/5 % are detected, respectively, in addition to the C/O component. The high concentration of C/O components observed on pipe surfaces and cross sections is considered to be MIC due to the various bacteria present. It is assumed that this is related to the heat-shrinkable sheet, which is a corrosion-resistant coating layer that becomes the MIC by-product component. The MIC generated on the pipe surface and cross section is inferred to have a high concentration of N components. High concentrations of N components occur frequently on surface and inner regions; these regions were investigated and Na/Mg/Ca basic substances were found to have accumulated as well. Therefore, it is presumed that the corrosion of buried pipes is due to the MIC of the NRB (nitrate reducing bacteria) reaction in the soil.

MacMic System for Flat Panel Display

  • Lee, Ui-Taek;Bae, Gi-Seon;Park, Chang-Hyeon;Gwon, Sang-Jik
    • Information Display
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    • v.4 no.2
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    • pp.3-6
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    • 2003
  • This paper describes a MacMic System developed for Flat Panel Display. The MacMic System usually is used for testing of Mother Glass of TFT and Color Filter. They are normally consisted of microscopy system, illumination system and panel stage system.

Antifungal Activity of Methyl 2-Benzimidazole Carbamate

  • Kim, Mal-Nam;Park, Hye-Young
    • Mycobiology
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    • v.31 no.2
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    • pp.81-85
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    • 2003
  • Antifungal properties of methyl 2-benzimidazole carbamate(BMC) were investigated using 16 fungi. Cytotoxicity test of BMC revealed that the morphology of HeLa cells was considerably deformed even at the concentrations as low as 0.1 ppm. Minimum inhibitory concentration(MIC) values of BMC for 7 fungi among the 16 tested ones were lower than $1.95{\times}10^{-4}{\mu}g/ml$, while Aspergillus flavus showed an MIC value higher than 1.0 ${\mu}g/ml$. Tolerance induction against BMC was successful only for Paecilomyces farinosus LAR10, contrary to the expectation that tolerance would be induced for the fungi having high MIC values such as Aspergillus niger ATCC 9642 and A. flavus ATCC 9643. Spore germination of A. niger ATCC 9642 was suppressed by BMC. However the mycelial growth of the fungus once germinated was not retarded at all by BMC up to 8 MIC. Addition of lanosterol provided a remedy for the reduced germination rate of A. niger ATCC 9642 spores.

On Comparison Of The Multicast Protocols Based On Qos (QoS 기반의 멀티캐스트 프로토콜 비교에 관한 연구)

  • Choi, Jun;Choi, Won-Hyuck;Lee, Tae-Seung;Kim, Jung-Sun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.05b
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    • pp.1237-1240
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    • 2003
  • 최근 대두되고 있는 멀티미디어 응용을 지원하기 위해서는 광대역 네트워크의 링크, 실시간 전송, 보다 효과적인 멀티캐스트 프로토콜이 요구된다. 멀티캐스트 프로토콜 알고리즘에는 DVMRP, MOSPF, CBT, PIM 구조의 멀티캐스팅 프로토콜 있다. 이는 네트워크 패킷의 특성을 송수신의 경로비용으로 라우터 자체의 근거리 알고리즘이 적용되고 있다. 본 연구에서는 인터넷에서 멀티캐스트 라우팅 프로토콜인 QosMIC를 제안한다. QosMIC는 멀티캐스트 네트워크에서 신뢰성과 능률적 자원관리와 탄력적인 방법으로 Qos특징을 제공한다. QosMIC는 확인된 다중경로에서 하나의 라우터를 선택하여 경로를 선택하고, 경로에서 요구하는 Qos를 제공한다. QosMIC는 데이터를 미리 제공하는 방식에 있어 이전의 프로토콜과 다르다. 본 연구에서는 QosMIC와 CBT를 분석하여 각 데이터 패킷 전송을 위한 공정하고 실용적인 대역폭 사용과 대역폭과 데이터처리능력을 시뮬레이션 상에서 구현하고 성능을 평가한다.

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The Experimental Study on Anti-bacterial Potency of Soyum Herbal-acupuncture, Hwangryunhaedoktang & Coptidis rhizoma on Staphylococcus epidermidis (소염 약침액, 황련해독탕, 황련이 Staphylococcus epidermidis에 미치는 항균효과에 대한 실험적 연구)

  • Seo, Hyung-Sik
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.2
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    • pp.19-25
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    • 2006
  • Objective : This experimental study was performed to investigate the effect of Soyum Herbal-acupuncture, Hwangryunhaedoktang & Coptidis rhizoma on Staphylococcus epidermidis that induce keratitis. Methods : MIC was measured by dropping to $50{\mu}l$ according to density Soyum Herbal-acupuncture, Hwangryunhaedoktang & Coptidis rhizoma(100%, 10%, 1%, 0.1%). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on Staphylococcus epidermidis in Soyum Herbal-acupuncture dippear all sample. 2. MIC on Staphylococcus epidermidis in Hwangryunhaedoktang disappear all sample. 3. MIC on Staphylococcus epidermidis in Coptidis rhizoma was 100%, $50{\mu}l$ and anti-bacterial potency increase compare with quantity. Conclusions : The present author think that Soyum Herbal-acupuncture must be extracted a new method for anti-bacterial potency and Coptidis rhizoma was made Herbal-acupuncture for eye drops.

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