• Title/Summary/Keyword: $MIC_{50}$

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Synergic Effect of Mahwangyounpae-tang and Ciprofloxacin on 5 Strains of Aerobic Gram-negative Bacteria (마황윤폐탕(麻黃潤肺湯)과 Ciprofloxacin의 병용(倂用)이 호기성 Gram(-) 세균주(細菌株)에 대한 시험관내(試驗管內) 항균력(抗菌力)에 미치는 영향)

  • Liu, Han-Hsiang;Park, Mee-Yeon;Choi, Hae-Yun;Gu, Deok-Mo;Kim, Jong-Dae;Song, Kwang-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.3
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    • pp.684-689
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    • 2005
  • In order to evaluate the in vitro synergic effect of Mahwangyounpae-tang which was a traditional poly-herbal formula has been used in the treatment of respiratory diseases in oriental medicine, and quinolone antibiotics, ciprofloxacin (CPFX), the minimal inhibitory concentration (MIC), $MIC_{50}$ and MIC90 of single use of quinolones and concomitant treatment with Mahwangyounpae-tang against 5 strains of aerobic gram negative bacteria, Escherichia coli, Klebsiella peumoniae, Hemophilus influenzae, Citrobacter freundii and Pseudomonas aeruginosae. The obtained results were as follows : In the case of aerobic gram negative bacteria, the MIC, $MIC_{50}$ and $MIC_{90}$ against Klebsiella peumoniae and Pseudomonas aeruginosae was significantly decreased in concomitant treated groups with Mahwangyounpae-tang compared to those of single treated groups of CPFX, respectively. However, no significant changes were demonstrated against Echerichia coli, Hemophilus influenzae and Citrobacter freundii. According to these results, it is considered as the in vitro antibacterial activity of CPFX was dramatically increased by concomitant use of Mahwangyounpae-tang against some strains of aerobic gram negative bacteria and the increase and selectivity of antibacterial activities against strains were chosen by the selectivity of Mahwangyounpae-tang not CPFX activity.

Effects of In Vrtro Synergism of Eunkyo-san and Ciprofloxacin against 9 Strains of Aerobic Gram(+) Bacteria (은교산과 Ciprofloxacin 병용이 호기성 Gram(+) 세균주에 대한 시험관내 항균력에 미치는 영향)

  • Sin Chang-Ho;Song Kwang-Kyu;Park Mee-Yeon;Choi Hae-Yun;Kim Jong-Dae
    • The Journal of Korean Medicine
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    • v.26 no.1 s.61
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    • pp.195-205
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    • 2005
  • Objective & Methods: To evaluate the in vitro synergic effect of Eunkyo-san, a traditional poly-herbal formula used in the treatment of respiratory diseases in oriental medicine with quinolone antibiotics, represented by ciprofloxacin (CPFX), which was used in the minimal concentration (MIC), $MIC_{50}$ and $MIC_{90}$. of single use of quinolones in concomitant treatment with Eunkyo-san against 9 strain$ of gram positive bacteria. Results: In. the case of aerobic gram positive bacteria, the MIC, $MIC_{50}$ and $MIC_{90}$ against Staphylococcus aureus, Staphylococcus aureus smith, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae Type I, Type II and Type III were significantly decreased in concomitant treated groups with Eunkyo-san compared to those of single treated groups of CPFX, respectively. However, no significant changes were demonstrated against Bacillus subtilis and Enterococcus faecalis. Conclusion: The in vitro antibacterial activity of CPFX were increased against some strains of gram positive strains, especially, pneumococcus such as Staphylococcus and Streptococcus, by concomitant use of Eunkyo-san.

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Variation of Antifungal Activities of Chitosans on Plant Pathogens

  • Park, Ro-Dong;Jo, Kyu-Jong;Jo, You-young;Jin, Yu-Lan;Kim, Kil-Yong;Shim, Jae-Han;Kim, yong-Wong
    • Journal of Microbiology and Biotechnology
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    • v.12 no.1
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    • pp.84-88
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    • 2002
  • The effect of chitosan on the growth of plant pathogenic fungi was investigated. Chitosan solubilized in acetic acid showed much higher and more consistent antifungal activity than that solubilized in HCl. The antifungal activity was not significantly affected within a DA (degree of deacetylation) range of $57.3-99.2\%$ tested. Water-soluble and low molecular weight chitosan ($57.3\%$ DA) against 6 plant pathogens showed that Monosporascus canonballus and Pythium irregulare were the most susceptible to the chitosan, while Fusarium oxysporum and F. graminearum were the most resistant. At a concentration of 2.5 mg/ml, the growth of pathogens was completely inhibited except for F. oxysporum. The $MIC_50$ values varied depending on both the DA of the chitosan and the plant pathogens. A chitosan with $57.3\%$ DA exhibited the lowest $MIC_50$ (ranging <0.1-1.8 mg/ml) and that with $84.7\%$ DA the highest $MIC_50$ (ranging <0.4-4.0 mg/ml) depending on the pathogen.

Antimicrobial Activity of Niaouli (Melaleuca quinquenervia) Leaf Extracts against Skin Flora (피부 상재균에 대한 니아울리 잎 추출물의 항균활성)

  • Jang, Ha Na;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.3
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    • pp.313-320
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    • 2014
  • In this study, the antimicrobial activity of niaouli leaf extracts was evaluated against skin flora. The skin flora used for experiments were three gram-positive bacteria such as Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Propionibacterium acnes (P. acnes), and two gram-negative, Escherichia coli (E. coli), Pseudomonas aeruginosa( P. aeruginosa), and the yeast, Plasmodium ovale (P. ovale). The bioassay applied for determining the antimicrobial effects of niouli leaf extracts or fraction included the disc diffusion assay and broth dilution assay. Minimum inhibitory concentration (MIC) values of 50% ethanol extract on B. subtilis, S. aureus, P. acnes, E. coli and P. aeruginosa were 0.25%, 0.50%, 1.00%, 0.13% and 0.25% respectively and the MIC values of water fraction were 0.25%, 0.25%, 4,00%, 0.25% and 0.25%. P. ovale did not show antimicrobial activities. The MIC values of methyl paraben used as positive control indicated 0.25%, 0.25%, 0.25%, 0.13% and 0.50%. Also, Minimum bactericidal concentration (MBC) values of 50% ethanol extract were 2.00%, 2.00%, 1.00%, 0.50% and 2.00% individually and the MBC values of water fraction were 0.50%, 0.25%, 4.00%, 0.50% and 1.00%. The MBC values of methyl paraben indicated 1.00%, 0.500%, 0.50%, 0.50% and 1.00%. These results showed that water fraction was as good as methyl paraben except for P. acnes. The 50% ethanol extract also showed activity similar with it. Thus, it is concluded that the 50% ethanol extract/fraction of niaouli could be applicable to cosmetics as a natural preservatives effective in antimicrobial activity against skin flora.

Antibiotics Susceptability of Streptococcus pneumoniae Isolated from Pharynx in Healthy Korean Children and Choice of Proper Empirical Oral Antibiotics Using Pharmacokinetics/Pharmacodynamics Model (국내의 소아에서 분리된 폐구균의 항생제 감수성 양상 및 약력동학 모델을 이용한 적절한 항생제의 선택)

  • Paik, Ji Yeun;Choi, Jae Hong;Cho, Eun Young;Oh, Chi Eun;Lee, Jina;Choi, Eun Hwa;Lee, Hoan Jong
    • Pediatric Infection and Vaccine
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    • v.18 no.2
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    • pp.109-116
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    • 2011
  • Purpose : Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. Methods : Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for ${\beta}$-lactams and macrolide. For the ${\beta}$-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. Results : Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC ${\leq}$1.0 ${\mu}g$/mL and 19 (82.6%) were MIC ${\leq}$2 ${\mu}g$/mL for amoxicillin. Amoxicillin 40 mg/kg/day achieved PTA >90% at MIC ${\leq}$1.0 ${\mu}g$/mL but PTA decreased to 52% at MIC 2 ${\mu}g$/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 ${\mu}g$/mL. Overall, oral amoxicillin 90 mg/ kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. Conclusion : Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.

Evaluation of in Vitro and in Vivo Antibacterial Activity of DWQ-217, a Fluoroquinolone (Fluoroquinolone계 항생제인 DWQ-217의 in vitro와 in vitro 항균작용)

  • 김병오;최문정;한승희;김지연;심점순;박남준;손호정;이재욱;유영효
    • YAKHAK HOEJI
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    • v.39 no.4
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    • pp.351-359
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    • 1995
  • The in vitro and in vivo antibacterial activities of DWQ-217 (1-cyclopropyl-6-fluoro-8-chloro-7-(3-amino-4-methylthiomethylpyrrolidinyl )-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid) were compared with those of ciprofloxacin (CPFX) and vancomycin(VCM). DWQ-217 was superior to those of CPFX and VCM against gram positive bacteria. DWQ-217 showed excellent activity against MRSA (MIC of methicillin; $\geq$12.5 $\mu\textrm{g}$/ml), MIC$_{90}$=0.013. DWQ-217 possessed strong bactericidal action against gram positive and gram negative strains by MIC/MBC test and killing curve. DWQ-217 and CPFX were administered orally and subcutaneously to mice infected systematically with S. aureus and S. pyogenes, DWQ-217 was $\geq$5-16 fold(p.o.) and $\geq$3-5 fold(s.c.) more active than CPFX.

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The Experimental Study on Anti-bacterial Potency of Jinpi-san on Staphylococcus aureus & Staphylococcus epidermidis. (진피산(秦皮散)이 Staphylococcus aureus와 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.20 no.1 s.32
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    • pp.195-200
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    • 2007
  • Objective : This experimental study was performed to investigate the effect of Jinpi-san on Staphylococcus aureus(S. aureus) and Staphylococcus epidermidis(S. epidermidis) that induce keratitis. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$ according to density Jinpi-san(100%, 10%, 1%, 0.1 %). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on S. aureus in Jinpi-san was $40{\mu}l$ undiluted solution. 2. MIC on S. epidermidis in Jinpi-san was $20{\mu}l$ undiluted solution. Conclusions : These results indicate that Jinpi-san can be used to cure S. aureus, S. epidermidis that induce eye disease(keratitis). If further study is performed, the use of eye drops will be valuable and beneficial in the clinical medicines.

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The Experimental Study on Anti-bacterial Potency of Hwangryunhaedoktang Herbal-acupuncture & extract on Staphylococcus aureus & Staphylococcus epidermidis (황련해독탕 약침액과 전탕액이 Staphylococcus aureus와 Staphylococcus epidermidis에 미치는 항균효과에 대한 실험적 연구)

  • Seo, Hyung-Sik
    • Journal of Pharmacopuncture
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    • v.9 no.2
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    • pp.99-103
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    • 2006
  • Objective : This experimental study was performed to investigate the effect of Hwangryunhaedoktang Herbal-acupuncture & extract on Staphylococcus aureus and Staphylococcus epidermidis that induce keratitis. Methods : MIC was measured by dropping to $50{\beta}^{\circ}$ according to density Hwangryunhaedoktang Herbal-acupuncture & extract(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 aureus in Hwangryunhaedoktang Herbal-acupuncture & extract were not disappear all sample. 2. MIC on Staphylococcus epidermidis in Hwangryunhaedoktang Herbal-acupuncture & extract were not disappear all sample. Conclusions : The present author think that Hwangryunhaedoktang Herbal-acupuncture must be extract a new method for anti-bacterial potency.

The Experimental Study on Anti-bacterial Potency of Soyum Herbal-acupuncture on Staphylococcus aureus & Staphylococcus epidermidis (소염 약침액이 Staphylococcus aureus와 Staphylococcus epidermidis에 미치는 항균효과에 대한 실험적 연구)

  • Seo, Hyung-Sik
    • Journal of Pharmacopuncture
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    • v.9 no.2
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    • pp.73-77
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    • 2006
  • Objective : This experimental study was performed to investigate the effect of Soyum Herbal-acupuncture on Staphylococcus aureus and Staphylococcus epidermidis that induce keratitis. Methods : MIC was measured by dropping to $50\;{\mu}l$ according to density Soyum Herbal-acupuncture(100%, 10%, 1%, 0.1%). Antibacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on Staphylococcus aureus in Soyum Herbal-acupuncture disappear all sample. 2. MIC on Staphylococcus epidermidis in Soyum Herbal-acupuncture disappear all sample. Conclusions : The present author think that Soyum Herbal-acupuncture must be extract a new method for anti-bacterial potency.

Characterization and Frequency of Vancomycin Resistance in Staphylococcus aureus Isolated in Korea (국내에서 분리된 포도상구균의 Vancomycin 내성빈도 및 특성)

  • 박성언;김종배
    • Biomedical Science Letters
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    • v.6 no.3
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    • pp.201-208
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    • 2000
  • The vancomycin, one of the family of glycopeptide antibiotics, inhibits the synthesis of bacterial cell wall peptidoglycan and has been widely used against gram-positive bacterial infections, especially for a treatment of methicillin resistant S. aureus infection. However, clinical isolate which was intermediately resistant to vancomycin (Mu50: MIC 8 $\mu\textrm{g}$/ml) was isolated in recent years. In this study we performed vancomycin susceptibility test with the increment method and population analysis with clinical isolates S. aureus. Also we did several kinds of tests with three selected isolates (s129: MIC 7 $\mu\textrm{g}$/ml, s134: MIC 7 $\mu\textrm{g}$/ml, s135: MIC 8 $\mu\textrm{g}$/ml) to find out possible mechanism of vancomycin resistance. As a result, the prevalence of vancomycin resistant S. aureus isolates among S. aureus strains resistant to methicillin was 23.3% (25/107). The vancomycin resistances of isolated strains of S. aureus were between those of Mu5O and Mu3 strains. By PCR analysis, none of the isolates with decreased vancomycin susceptibility contained known vancomycin resistant genes such as vanA, vanB, vanC1, vanC2, and vanH. Major bands of 81 kDa, 58 kDa, 33 kDa, 28 kDa were demonstrable in whole cell lysates by SDS-PAGE from all three isolates as well as reference strains. And especially,45 kDa protein was overproduced in Mu50 strains. Among them increased production of NAD$^{+}$-linked-$_{D}$-lactate dehydrogenase (dnLDH) were detected from one clinical strain (s135) and Mu5O strain. From these data, we suggest that the mechanism of vancomycin resistance in these isolates are distinct from that in enterococci.

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