• Title/Summary/Keyword: sources of resistance

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Protoberberine Alkaloids and their Reversal Activity of P-gp Expressed Multidrug Resistance (MDR) from the Rhizome of Coptis japonica Makino

  • Min, Yong-Deuk;Yang, Min-Cheol;Lee, Kyu-Ha;Kim, Kyung-Ran;Choi, Sang-Un;Lee, Kang-Ro
    • Archives of Pharmacal Research
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    • v.29 no.9
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    • pp.757-761
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    • 2006
  • Six protoberberine alkaloids were isolated from the chloroform layer of the rhizome of Coptis japonica Makino (Ranunculaceae). The structures of the isolated compounds were determined to be 6-([1,3]dioxolo[4,5-g]isoquinoline-5-carbonyl)-2,3-dimethoxy-benzoic acid methyl ester (1), oxyberberine (2), 8-oxo-epiberberine (3), 8-oxocoptisine (4), berberine (5) and palmatine (6) by physicochemical and spectroscopic methods. The compound 3 (8-oxo-epiberberine) was first isolated from natural sources. The compounds were tested for cytotoxicity against five tumor cell lines in vitro by SRB method, and also tested for the MDR reversal activities. Compound 4 was of significant P-gp MDR inhibition activity with ED50 value $0.018\;{\mu}g/mL$ in MES-SA/DX5 cell and $0.0005\;{\mu}g/mL$ in HCT15 cell, respectively.

Effects of waste marble and glass powders on concrete properties and performance

  • Nouraldin Abunassar;Tulin Akcaoglu
    • Advances in concrete construction
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    • v.17 no.4
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    • pp.211-220
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    • 2024
  • Concrete, consisting mainly of cement, water and aggregates; is the most used construction material all over the world. Cement manufacturing industry is one of the carbon dioxide producing sources that contributes to global warming. Therefore, in the last few years, there is a growing interest in using waste materials and by-products as cement replacement materials. Using these kinds of materials as a part of cement replacement reduces the air pollution, cost and also enhances some properties of concretes. In the present work, marble dust (MD) was examined as a partial cement replacement material with seven proportions as 0%, 10%, 20%, 30%, 40%, 50%, 60% and glass powder (GP) was used as an additive, 8% by cement weight, in a 0.55 water-binder ratio concrete. In order to evaluate their effects; workability, strength (compressive, flexural and split tensile), alkalinity, sulphate resistance and ultrasonic pulse velocity tests were performed. Experimental results indicated that with MD replacement and GP addition; there is a loss in the workability but improvement in mechanical properties. With 10% replacement of MD compressive, flexural and tensile strengths increased by 10.7%, 6.2% and 5.3% respectively. Moreover, up to 30% replacement of MD reasonable strength values were obtained.

Survey of Antibiotic Resistant Bacteria in Lake Gyeongpo, Korea (경포호의 항생제 내성 세균 조사)

  • Dukki Han
    • Korean Journal of Environmental Agriculture
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    • v.42 no.3
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    • pp.169-176
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    • 2023
  • The emergence and spread of antibiotic-resistant bacteria have been increasing with anthropogenic contamination. Understanding the prevalence and distribution of these resistant bacteria in environments is crucial for effectively managing anthropogenic pollutants. Lake Gyeongpo in the Gangwon Province of South Korea is known for its diverse ecological features and human interactions. The lake is exposed to pollutants from nonpoint sources, including urban areas, agricultural practices, and recreational activities, which can introduce antibiotics and foster antibiotic resistance in bacteria. The present study investigates Lake Gyeongpo as a potential reservoir for antibiotic-resistant bacteria in a natural ecosystem. A total of 203 bacterial isolates were collected from six sampling locations in Lake Gyeongpo during May, July, and November 2022. Most isolates were taxonomically identified as Pseudoalteromonas, Bacillus, Shewanella, and Vibrio spp.; their abundance showed a spatiotemporal distribution. An antibiotic susceptibility test was conducted on 75 isolates using the disk diffusion method with six drugs according to the CLSI guideline; 42 isolates were resistant to one or more antibiotics. Among these, 15 isolates were identified as multidrug resistant bacteria. This finding suggests the potential anthropogenic impact on Lake Gyeongpo and provides valuable insights into the dissemination of antibiotic resistance caused by anthropogenic pollutants.

Field Evaluation of Mungbean Recombinant Inbred Lines against Mungbean Yellow Mosaic Disease Using New Disease Scale in Thailand

  • Akhtar, Khalid P.;Kitsanachandee, R.;Srinives, P.;Abbas, G.;Asghar, M.J.;Shah, T.M.;Atta, B.M.;Chatchawankanphanich, O.;Sarwar, G.;Ahmad, M.;Sarwar, N.
    • The Plant Pathology Journal
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    • v.25 no.4
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    • pp.422-428
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    • 2009
  • Studies were conducted to identify the sources of resistance in mungbean recombinant inbred lines (RILs) in Thailand against mungbean yellow mosaic disease (MYMD). 146 mungbean RILs in $F_8$ series were evaluated in a field including resistant parent NM-10-12-1 and susceptible parent KPS 2 during summer 2008 under high inoculum pressure. The RILs were subsequently scored for disease symptom severity ratings (DSSR) using a new scale. Observations regarding DSSR and % disease index (%DI) showed that the tested RILs responded differently to the disease. A large number of RILs (132) were found highly susceptible, 12 were susceptible, 3 were tolerant and one was resistant. Overall screening results showed that three RILs, viz. line no. 30, 100 and 101 had minimum DSSR and % disease index thus they are good source of resistance to MYMD in spite of high disease pressure and can therefore be used directly as varieties to manage the disease in Thailand.

A Study on the Characteristics of Fire Resistance of Window Material in Compartment Fire (건물화재시 창문재료에 따른 내화특성 연구)

  • Hur, Man-Sung;Jang, Moon-Seok;Cho, Soo
    • Fire Science and Engineering
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    • v.17 no.1
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    • pp.62-67
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    • 2003
  • The full-scale compartment fire tests were carried out to evaluate the characteristics of fire resistance of window material under actual fire conditions. The room size used for full-scale room fire tests was 4 by 3.8 m with 2.4 m high ceiling. The windows with PVC, Aluminum and AL+Wood frame materials were established, sofa and mattress were used as fire sources. The window contained pair glasses with the air between 6 mm glasses. Temperatures at total 32 points in the room were measured to find the temperature distribution in the room fire. It is examined that thermal effects on window frame materials such as charring, distortion, melting, structural collapse, and other effects.

Studies on the Selective Media for Bifidobacterium infantis Maeil-K9 Using Various Carbon Sources and Antibiotics (Bifidobacterium infantis Maeil-K9 균주의 당 발효 특성 및 항생제 내성을 이용한 선택배지 개발연구)

  • 정병문;김응률;정후길;전호남
    • Korean Journal of Microbiology
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    • v.40 no.1
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    • pp.37-42
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    • 2004
  • To differentiate commercial bifidobacteia for Bifidobacterium lactis Bb-12, Bif. longum Bb-536 and Bif. infantis Maeil-K9, we studied the various carbon source, the nitrogen sources and antibiotics. Amygdalin and fructose were good candidates for carbon sources, and tryptone was suitable for nitrogen sources to design a new selective media for three commercial bifidobacteria. In the case of the amygdalin-containing medium as carbon sources, Bif. lactis Bb-12 and Bif. infantis Maeil-K9 showed good growth, and in fructose-containing medium, Bif. longum Bb-536 showed good growth. In antibiotics resistance study, the addition of 1 mg/L doxycyclin was very effective for differentiation of each bifidobacteria. Doxycyclin did not affect the growth of Bif. lactis Bb-12 and Bif. infantis Maeil-K9, but Bif. longum Bb-536 was completely inhibited by doxycyclin. Finally to confirm the selection capability of newly designed selective media, temperature-shocked bifidobacteria were cultured on them. As the results, fructose or doxycyclin containing medium showed for high growth for temperature-shocked bifidobacteria, but amygdalin containing medium showed low growth of temperature-shocked bifidobacteria.

Variations in Phenotypic Characteristics, Pathogenicity and Fungicides Resistance of Botrytis cinerea, Gray Mold Rot Fungus, Isolated from Various Host Plants (잿빛곰팡이 병원균 Botrytis cinerea 균주의 분리기주별 표현형적 특성, 병원성 및 약제저항성 변이)

  • Choi, In-Sil;Chung, Young-Ryun;Cho, Kwang-Yun
    • The Korean Journal of Mycology
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    • v.23 no.3 s.74
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    • pp.246-256
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    • 1995
  • Phenotypic characteristics, pathogenicity and fungicides resistance of fifty one isolates of Botrytis cinerea obtained from various host plants were observed and determined. The relationships between these characteristics were also investigated on the basis of isolation host plants. The isolates of B. cinerea varied in the capacity of sclerotia formation and sporulation. The pathogenicity of 44 isolates from tomato, cucumber, and strawberry was significantly stronger with 3.2 cm in average diameter of necrotic lesions on cucumber leaves than that of seven isolates from other host plants such as orange, gerbera, ginseng, kiwi, grape, pear and from butter with 1.8 cm in average diameter of necrotic lesions. Benomyl resistance of 12 isolates from tomato plants was much higher with the $EC_{50}$, 562 ppm than that of 19 isolates from various host plants. Diethofencarb resistance, however, of 11 isolates from strawberry plants was highest with the $EC_{50}$, 210 ppm among isolates from other host plants. Polygalacturonase activity varied among isolates in the range of 0 to 103 unit and that of isolates from tomato, cucumber and strawberry was slightly lower than that of isolates from other host plants. No significant relationship between pathogenicity and fungicides resistance, polygalacturonase activity was found among 51 isolates of B. cinerea. Isozyme patterns of polygalacturonase produced from two strongly and weakly pathogenic isolates (FC122, KC6) were slightly different depending upon carbon sources during cultivation.

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Prevalence of chloramphenicol-resistant gene in Escherichia coli from water sources in aquaculture farms and rivers of Kuching, Northwestern Borneo

  • Leong, Sui Sien;Lihan, Samuel;Toh, Seng Chiew
    • Fisheries and Aquatic Sciences
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    • v.25 no.4
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    • pp.202-213
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    • 2022
  • Antibiotic resistant Escherichia coli cases are increasing high especially in Southeast Asia. Illegal use of the antibiotic in the aquaculture farming may become the culprit of the outbreak and spread into environmental source. A study was conducted to: 1) detect the chloramphenicol (CAL)-resistant gene in E. coli isolated from three aquaculture farms and six rivers of northwestern Borneo and 2) investigate the correlation between cat gene with five common antibiotics used. Isolation of E. coli was done on Eosin methylene blue agar and characterized using indole, methyl red, Voges-Proskauer, citrate tests. E. coli isolates were subsequently tested for their susceptibility to five antibiotics commonly used in aqua-farming. The CAL-resistant E. coli were further analyzed for the presence of resistant genes (cat I, cat II, cat III, cat IV) using multiplex polymerase chain reaction. 42 bacterial colonies were isolated from a total of 80 individual water samples, 34 of which were identified as E. coli. Result showed 85.3% of the E. coli isolates were resistant to amoxicillin, 35.3% were resistant to tetracycline, 29.4% were resistant to CAL, 17.6% were resistant to nitrofurantoin and 8.8% were resistant to nalidixic acid. All of the 10 CAL resistant E. coli isolateswere detected with cat II genes; five isolates detected with cat IV genes; three isolates detected with cat III genes; and another two detected with cat I genes. Pearson correlation coefficient shows highly significant relationship between resistance pattern of CAL with amoxicillin; and CAL with tetracycline. Our findings provide the supplementary information of the CAL resistance gene distribution, thereby improving our understanding of the potential risk of antibiotic resistance underlying within this microbial ecosystem.

Evaluation of Uncertainty Sources in Temperature Measurement Using Platinum Resistance Thermometer Caused by Temperature Gradient in Furnace and Sealed-type Freezing Point Cells (전기로 및 봉입형 응고점 셀 내의 온도구배가 미치는 표준백금저항온도계 온도측정의 불확도 요소 평가)

  • Kang, Kee-Hoon;Gam, Kee-Sool;Kim, Yong-Gyoo;Song, Chang-Ho
    • Journal of Sensor Science and Technology
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    • v.13 no.6
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    • pp.411-416
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    • 2004
  • In the international temperature scale of 1990 (ITS-90), standard platinum resistance thermometer (SPRT) is a defining standard thermometer used in the temperature range from 13.8033 K to $961^{\circ}C$. Uncertainty of SPRT is about several mK and uncertainty of defining fixed points of the ITS-90 which is used for calibrating SPRT is about several tenth of mK. Above $0^{\circ}C$. the defining fixed points are gallium melting point and indium, tin, zinc, aluminium and silver freezing points which are all realized using an electric furnace or a liquid bath. To realize freezing point of tin ($231.928^{\circ}C$) and zinc ($419.527^{\cir}C$), two 3-zone furnaces which have 3 electric heaters were manufactured. Temperature gradient of the constructed furnaces were tested. Uncertainty caused by temperature gradient of furnace and immersion effect of SPRT in the sealed-type freezing point cells were evaluated 0.038 mK for tin freezing point and 0.036 mK for zinc freezing point.

Effects of Various Chemical Substrates on Heat Resistance of Isolated Enterobacter sp. (각종 화학기질이 분리된 Enterobacter sp. 의 열저항서에 미치는 효과)

  • 정영건;권오진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.4
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    • pp.395-400
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    • 1991
  • Effects of Various Chemical Substrates on Heat Resistance of Isolated EnterobTo pursue the various properties of Enterobacter sp. which may give an outbreak of food-borne disease to man, isolated from the meats and the small intestines of wild mice, and to offer the significant data in the fields of food hygiene and public health this study was carreied, 5 strains of Enterobacter sp. were isolated from the above samples. 5 strains isolated from sample sources were 1 strain (E. aerogenes) from the beeves, 2 strains (E. aerogenes, E intermedium) from the pork and 2 strains (E. aerogenes, E. cloacae) from the small intstines of wild mice. Of total isolatd 89 strains, including non-Enterobacter sp., these numbers of 5 isolates were showed as 5.6% of dection rate. On heating at temperature of $55^{\circ}C$ for 30min., these 5 stratins were generally more resisted in the 0.1M phosphate buffer when such chemical substrates as 0.1M glycine, 5% mannitol or 0.5% sorbitol was added to it whereas they were appeared weaker resistances in 0.1M phosphate buffer when 1% sodium citrate, 1% casein, 10% sodium chloride or 0.1M systein was infused into it.cter sp.

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