• Title/Summary/Keyword: biological resistance

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Biological activity of Ethaboxam: the first Korean fungicide

  • Kim, Dal-Soo;Chun, Sam-Jae
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2004.10a
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    • pp.36-38
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    • 2004
  • Ethaboxam is a new fungicidal active ingredient that inhibits growth of plant pathogens specifically belonging to Oomycetes with protective, curative, systemic and translaminar activity in plants. Modes of action studies revealed that ethaboxam simultaneously inhibits cytoskeleton formation and mitochondrial respiration of Phytophthora infestans at low concentrations. There have been no indications of resistance development when tested for baseline resistance monitoring to 261 isolates of P. infestans in Korea and Europe and 150 populations of Plasmopara viticola populations in Europe for 3 years since 2000. In a selective study with vine trees artificially inoculated with P. viticola repeatedly for 10 generations in greenhouse, there have been no changes in sensitivity to ethaboxam among four natural populations of P. viticola. Furthermore, ethamoxam has not shown any cross resistance with azoxystrobin, mefenoxam, dimethomorph and cymoxanil. Based on the study results from modes of action and resistance development, ethaboxam appears to be unlikely to develop resistance in field applications.

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Comprehensive Overview of Candida auris: An Emerging Multidrug-Resistant Fungal Pathogen

  • Ji-Seok Kim;Hyunjin Cha;Yong-Sun Bahn
    • Journal of Microbiology and Biotechnology
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    • v.34 no.7
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    • pp.1365-1375
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    • 2024
  • The rise of Candida auris, a multidrug-resistant fungal pathogen, across more than 40 countries, has signaled an alarming threat to global health due to its significant resistance to existing antifungal therapies. Characterized by its rapid spread and robust drug resistance, C. auris presents a critical challenge in managing infections, particularly in healthcare settings. With research on its biological traits and genetic basis of virulence and resistance still in the early stages, there is a pressing need for a concerted effort to understand and counteract this pathogen. This review synthesizes current knowledge on the epidemiology, biology, genetic manipulation, pathogenicity, diagnostics, and resistance mechanisms of C. auris, and discusses future directions in research and therapeutic development. By exploring the complexities surrounding C. auris, we aim to underscore the importance of advancing research to devise effective control and treatment strategies.

Suppression of Bacterial Wilt with Fuorescent Pseudomonads, TS3-7 strain (Fluorescent siderophore 생산균주, TS3-7에 의한 풋마름병 발병 억제)

  • Kim, Ji-Tae;Cho, Hong-Bum;Kim, Shin-Duk
    • Applied Biological Chemistry
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    • v.48 no.3
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    • pp.296-300
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    • 2005
  • Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.

Identification of to Hexapeptides that Render C2 Myoblasts the Resistant Menadione-induced Cell Death

  • Hwang, Sung-Ho;Kim, Min-Jeong;Lim, Jeong-A;Woo, Joo-Hong;Kim, Hye-Sun
    • Animal cells and systems
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    • v.12 no.1
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    • pp.35-39
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    • 2008
  • Menadione induced cell death in cultured C2 myoblasts. By screening synthetic peptide libraries composed of random sequence of hexapeptides, we identified the hexa-peptides pool of(Ala/Ile)-(Ile/Met)-Val-Ile-Asp-(Met/Ser)-$NH_2$ that protected the myoblasts against menadioneinduced cell death. Pre-incubation with the hexapeptide pool reduced the number of cells detached from culture dish substrate and increased the ratio of relative viability against menadione. In addition, the peptides strongly increased the expression of Bcl-2, an anti-apoptotic protein. These results suggest that the hexapeptides might enhance the resistance to cell death against menadione by increasing the expression of Bcl-2.

Isolation of Weissella strains as potent probiotics to improve antioxidant activity of salted squid by fermentation

  • Le, Bao;Yang, Seung Hwan
    • Journal of Applied Biological Chemistry
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    • v.61 no.1
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    • pp.93-100
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    • 2018
  • The aim of this study was to enhance the antioxidant activity of salted squid by inoculation of two Weissella spp. strains (W. cibaria FB-069 and W. viridescens FB-077) isolated from traditional Korea salted squid. The safety and probiotic potential characteristics of these two strains were evaluated. The safety of these strains was analyzed based on hemolytic activity, mucin degradation, biogenic amino production, and resistance to antibiotics. These lactic acid bacteria showed probiotic potential, including resistance to gastrointestinal tract conditions, adhesion to Caco-2 cells, and aggregation. The low-salted squid fermented with Weissella strains had consistently higher antioxidant activity through changing their amino acid profiles. Therefore, W. cibaria FB-069 and W. viridescens FB-077 might be good candidates for fermentation of salted squid to develop functional food with enhanced health benefits.

Preparation of tungsten metal film by spin coating method

  • Lee, Kwan-Young;Kim, Hak-Ju;Lee, Jung-Ho;Sohn, Il-Hyun;Hwang, Tae-Jin
    • Korea-Australia Rheology Journal
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    • v.14 no.2
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    • pp.71-76
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    • 2002
  • Metal thin films, which are indispensable constituents of ULSI (Ultra Large Scale Integration) circuits, have been fabricated by physical or chemical methods. However, these methods have a drawback of using expensive high vacuum instruments. In this work, the fabrication of tungsten metal film by spin coating was investigated. First of all, inorganic peroxopolytungstic acid (W-IPA) powder, which is soluble in water, was prepared by dissolving metal tungsten in hydrogen peroxide and by evaporating residual solvent. Then, the solution of W-IPA was mixed with organic solvent, which was spin-coated on wafers. And then, tungsten metal films, were obtained after reduction procedure. By selecting an appropriate organic solvent and irradiating UV, the sheet resistance of the tungsten metal film could be remarkably reduced.

Effect of Ionic Stress on the Stability of Bacterial Spores (세균 포자의 안정성에 미치는 이온 강도의 영향)

  • Rhee, Chong-Ouk
    • Applied Biological Chemistry
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    • v.19 no.2
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    • pp.75-81
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    • 1976
  • High ionic strength is expected to enhance dissociation of Ca-DPA from spores and to contribute to a detrimental effect on spore stability or on spore heat resistance with a combined treatment of gamma-radiation. From this study, this hypothesis has become apparent as as follows; 1) Ca-DPA dissociation contributes to loss of stability of bacterial spores with respect to heat resistance, survival during storage, and 2) the cytoplasmic membrane plays a role in maintaining the stability of DPA-Ca-spore complex, apparently by serving as a permeability barrier.

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Difficult Clinical Problems of Treatment in Depression (우울증 치료에서의 어려운 문제들)

  • Min, Kyung-Joon
    • Korean Journal of Biological Psychiatry
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    • v.8 no.1
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    • pp.37-46
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    • 2001
  • Whenever a clinician manages the patients with depression, he may meet various problems that make it difficult to treat them. Even though he has good skills and knowledge about depression, some barriers will be appear during his practice. In general, the difficulties in treating depression are treatment-resistance, adverse effects of antidepressants, pregnancy in female patients, comorbid medical conditions, poor compliance, drug-drug interactions, and so on, which are related with pharmacological treatments. Here, only the two of them, the treatment-resistant depression and difficult problems concerned with pregnancy, were discussed. Some level of treatment resistance is the norm rather than the exception. As the treatment failure stems from inadequate treatment, it is important that the clinician should prescribe medications with sufficient doseage and adequate duration. And to overcome the treatment resistant depression the polypharmacy is necessary, in that case, the side effects and toxicities should be explored and managed immediately. So the clinician have to learn more about the pharmacokinetic and pharmacodynamic mechanisms of each drugs used in treatment of depression. When the risk of the fetus by the exposure is higher than the risk of untreated maternal psychiatric disorder, psychotropic medications should be used during pregnancy. Women who are maintained on psychotropics and become pregnant, as well as women with the new onset of psychiatric symptoms during pregnancy, should be carefully reassessed. However, data concerning the potential risk of long-term behavioral changes following prenatal exposure to psychotropics is rare, so further longitudinal follow-up studies are needed.

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The Effects of Aromatherapy on Autonomic Nerve System and Physical Resistance of a Stress (아로마 요법이 뇌졸중환자의 자율신경계와 스트레스에 대한 신체 저항도에 미치는 효과)

  • Shin, Yoo-Sun;Cho, Young-Suk;Jung, Yu-Jin
    • Journal of Korean Biological Nursing Science
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    • v.6 no.2
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    • pp.5-17
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    • 2004
  • Purpose: The purpose of this study is to determine effects of aromatherapy on the activity and balance of autonomic nervous system and on physical resistance to stress. Methods: This research is a primitive experimental design which attempts to analyze aromatherapy EKG monitoring on real-time basis. Lavender & Chamomile, each 30 drops, were blended with 100ml Sweet Almond oil. Subjects was laid relaxed, and had insides of his wrists and ankles attached with electrodes for EKG. Right after applied with essential oil onto his philtrum and parotid, started on EKG monitoring. Results: The activities of parasympathetic and sympathetic nerve were changed as time elapsed, with significant differences(p=.000). In multiple comparison, the value was significantly different(p<.05).The balance of autonomic nerve was changed, becoming close to the normal level in accord with applicable international standards(1.5)(p=.011). In multiple comparison, the value showed a significant difference(p<.05). Physical resistance to stress increased with the passage of time, but not statistically significant. Conclusions: This suggests that aromatherapy can be used as a nursing intervention which aims at alleviating symptoms related to the imbalance of autonomic nerve system such as headache, hot flashes, irregular heartbeat, nervousness, depression and anxiety.

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Cloning and Sequence Analysis of the Aminoglycoside Resistance Gene from a Nebramycin Complex Producer, Streptoalloteichus hindustanus

  • Hyun, Chang-Gu;Kim, Jong-Woo;Han, Jae-Jin;Choi, Young-Nae;Suh, Joo-Won
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.146-151
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    • 1998
  • The aminoglycoside multiple-resistance determinant from Streptoalloteichus hindustanus was cloned into Streptomyces lividans and named nbrB. The 1.2-kb ApaI- BclI fragment encompassing nbrB was located within a 2.6-kb ApaI fragment by successive subcloning experiments. The complete DNA nucleotide sequence of 1.2-kb containing nbrB was determined. The sequence contains an open reading frame that putatively encodes a polypeptide of 281 amino acids with a predicted molecular weight of 30,992. The deduced amino acid sequence of nbrB shows identities of 85.1% to kgmB of S. tenebrarius, 59.6% to sgm of Micromonospora zionensis, and 57.7% to grm of M. rosea. The similarity of nbrB to kgmB suggests that nbrB encodes a 16S rRNA methylase similar to that encoded by kgmB and that both genes might be derived from a common ancestral gene.

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