• Title/Summary/Keyword: pathogen

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Selection of Effective Fungicides Against Xylogone sphaerospora, a Fungal Pathogen of Cultivated Mushroom, Ganoderma lucidum (영지 노랑병 방제에 효과적인 살균제의 선발)

  • 최경자;이종규;우성희;조광연
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.491-495
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    • 1998
  • A fungal disease of the cultivated mushroom, Ganoderma lucidum, caused by Xylogone sphaerospora was epidemic throughout all cultivation areas in Korea which caused a lot of yield losses in the mushroom production. For controlling the disease, the screening of effective fungicides against the pathogenic fungus were conducted. Thirty seven commercially available fungicides were tested for their inhibitory activities on potato dextrose agar media supplemented with these fungicides at various concentrations. Twenty one fungicides significantly inhibited mycelial growth of the pathogen, Xylogone sphaerospora, but 16 fungicides had no inhibitory effect. Among these 21 fungicides, 17 fungicides also inhibited mycelial growth of Ganoderma lucidum as well, but imazalil, procymidone, triforine, and vinclozolin had no inhibitory effects. However, vinclozolin showed no inhibitory effect on mycelial growth of the mushroom even at the concentration of 50 $\mu\textrm{g}$/ml vinclozolin solution for 2 hours, and then the pathogen was inoculated. After two month-cultivation of the mushroom, over 90% of logs treated with vinclozolin without pathogen inoculation produced fruiting bodies. However, fruiting bodies were not produced form the logs inoculated with the pathogen, but not treated with vinclozolin. Fifty seven percent of logs. which were pre-treated with vinclozolin and then inoculated with the pathogen produced fruiting bodies. Based on the results, vinclozolin is effective for the control of yellow disease of the Ganoderma lucidum caused by Xylogone sphaerospora.

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An integrated DNA barcode assay microdevice for rapid, highly sensitive and multiplex pathogen detection at the single-cell level

  • Jung, Jae Hwan;Cho, Min Kyung;Chung, So Yi;Seo, Tae Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.276-276
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    • 2013
  • Here we report an integrated microdevice consisting of an efficient passive mixer, a magnetic separation chamber, and a capillary electrophoretic microchannel in which DNA barcode assay, target pathogen separation, and barcode DNA capillary electrophoretic analysis were performed sequentially within 30 min for multiplex pathogen detection at the single-cell level. The intestine-shaped serpentine 3D micromixer provides a high mixing rate to generate magnetic particle-pathogenic bacteria-DNA barcode labelled AuNP complexes quantitatively. After magnetic separation and purification of those complexes, the barcode DNA strands were released and analyzed by the microfluidic capillary electrophoresis within 5 min. The size of the barcode DNA strand was controlled depending on the target bacteria (Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium), and the different elution time of the barcode DNA peak in the electropherogram allows us to recognize the target pathogen with ease in the monoplex as well as in the multiplex analysis. In addition, the quantity of the DNA barcode strand (~104) per AuNP is enough to be observed in the laser-induced confocal fluorescence detector, thereby making single-cell analysis possible. This novel integrated microdevice enables us to perform rapid, sensitive, and multiplex pathogen detection with sample-in-answer-out capability to be applied for biosafety testing, environmental screening, and clinical trials.

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Computational Identification of Essential Enzymes as Potential Drug Targets in Shigella flexneri Pathogenesis Using Metabolic Pathway Analysis and Epitope Mapping

  • Narad, Priyanka;Himanshu, Himanshu;Bansal, Hina
    • Journal of Microbiology and Biotechnology
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    • v.31 no.4
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    • pp.621-629
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    • 2021
  • Shigella flexneri is a facultative intracellular pathogen that causes bacillary dysentery in humans. Infection with S. flexneri can result in more than a million deaths yearly and most of the victims are children in developing countries. Therefore, identifying novel and unique drug targets against this pathogen is instrumental to overcome the problem of drug resistance to the antibiotics given to patients as the current therapy. In this study, a comparative analysis of the metabolic pathways of the host and pathogen was performed to identify this pathogen's essential enzymes for the survival and propose potential drug targets. First, we extracted the metabolic pathways of the host, Homo sapiens, and pathogen, S. flexneri, from the KEGG database. Next, we manually compared the pathways to categorize those that were exclusive to the pathogen. Further, all enzymes for the 26 unique pathways were extracted and submitted to the Geptop tool to identify essential enzymes for further screening in determining the feasibility of the therapeutic targets that were predicted and analyzed using PPI network analysis, subcellular localization, druggability testing, gene ontology and epitope mapping. Using these various criteria, we narrowed it down to prioritize 5 novel drug targets against S. flexneri and one vaccine drug targets against all strains of Shigella. Hence, we suggest the identified enzymes as the best putative drug targets for the effective treatment of S. flexneri.

Development of Enrichment Semi-nested PCR for Clostridium botulinum types A, B, E, and F and Its Application to Korean Environmental Samples

  • Shin, Na-Ri;Yoon, So-Yeon;Shin, Ji-Hun;Kim, Yun Jeong;Rhie, Gi-eun;Kim, Bong Su;Seong, Won Keun;Oh, Hee-Bok
    • Molecules and Cells
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    • v.24 no.3
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    • pp.329-337
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    • 2007
  • An enrichment semi-nested PCR procedure was developed for detection of Clostridium botulinum types A, B, E, and F. It was applied to sediment samples to examine the prevalence of C. botulinum in the Korean environment. The first pair of primers for the semi-nested PCR was designed using a region shared by the types A, B, E, and F neurotoxin gene sequences, and the second round employed four nested primers complementary to the BoNT/A, /B, /E, and /F encoding genes for simultaneous detection of the four serotypes. Positive results were obtained from the PCR analysis of five of 44 sediments (11%) collected from Yeong-am Lake in Korea; all were identified as deriving from type B neurotoxin (bontb) genes. Two of the C. botulinum type B organisms were isolated, and their bontb genes sequenced. The deduced amino acid sequences of BoNT/B showed 99.5 and 99.8% identity with the amino acid sequence of accession no. AB084152. Our data suggest that semi-nested PCR is a useful tool for detecting C. botulinum in sediments, and renders it practicable to conduct environmental surveys.

A Study on the Recognition of Dryness pathogen and Dryness disease - Focusing on the main argument in history - (조사(燥邪)와 조병(燥病)의 인식에 대한 고찰 - 역대 주요 논쟁을 중심으로 -)

  • Yun, Ki-ryoung;Jeong, Chang-hyun;Baik, You-sang;Jang, Woo-chang
    • Journal of Korean Medical classics
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    • v.30 no.1
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    • pp.111-133
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    • 2017
  • Objectives : Dryness pathogen, which is one of six pathogenic factors, causes dryness diseases. Currently, the theory on dryness disease is composed of external dryness and internal dryness. External dryness, in turn, is composed of cool dryness and warm dryness. However, these categorizations and their symptoms bear ambiguity for many reasons. Therefore, this paper aims to review various texts in order to study the special features of dryness pathogen and dryness disease. Methods : Texts that deal with dryness pathogen and dryness disease were studied. Most texts are comprised of dissertations and historical medical texts, therefore, CNKI and The Sikuquanshu's databases, and Traditional Chinese Medical(TCM) book webdatabases were utilized. Materials are listed in chronological order, and their main points regarding dryness pathogen and dryness disease are compared. Results & Conclusions : It is difficult to accept the assertion that dryness pathogen does not lead to external dryness. Dryness does not have the elements of chill and fever in itself. Dryness's elements of chill and fever are determined in the ways they combine with each individual element. Moreover, the symptoms of chill and fever on dryness disease are subject to the host's body type. External dryness and internal dryness cannot be discussed within an identical premise. Whereas the dryness in external dryness signifies the cause of a disease, the dryness in internal dryness is the consequence of a disease. In other words, internal dryness revolves around cause of disease and external dryness revolves around the mechanic of disease. It's difficult to determine whether these diseases are caused by dryness or wetness in Autumn. There is an understanding which integrates these together through the Yunqi theory, but it is imperfect.

A Study on the Development of the Understanding that the Cause of Warm Pathogen Lies in Upper Portion of Body ("온사상수(溫邪上受)" 개념의 형성요인에 대한 고찰)

  • Eun, Seokmin
    • Journal of Korean Medical classics
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    • v.30 no.2
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    • pp.11-29
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    • 2017
  • Objectives : Contemporary researches suspect that, contrary to the past belief, the understanding that the cause of warm pathogen lies in the upper portion of human body is an understanding that had been well-established even before Yetianshi. This new understanding now requires us to contemplate the process of theoretical development which this understanding, termed Onsasangsu, had taken within the boundary of the theory of warm pathogen. This paper aims to shed light on this within the framework that this is the emergence of a new theory of warm pathogen caused by a new understanding of warm pathogen. Methods : First, the theories of warm pathogen as developed by historical doctors were studied, and elements that seem to be related to the understanding of Onsasangsu were selected and studied to understand their theoretical characteristics. Furthermore, the paper studied what academic significance do these theories have on the development of the theory of warm pathogen. Results & Conclusions : Provided that the underlying assumption of Onsasangsu is that febrile diseases are caused through moutn and nose, the study showed that this understanding arose before the period of Qing Dynsasty from the need by many doctors to differentiate the pathogens of various diseases such as the disease of heat, febrile disease, and epidemic. The reason that these discussions could not have much impact on the study of febrile disease during the Qing Dynasty could be because they were not passed on down to the future generations, or because commonly held perspective was unable to accept criticisms.

Platform of Hot Pepper Defense Genomics: Isolation of Pathogen Responsive Genes in Hot Pepper (Capsicum annuum L.) Non-Host Resistance Against Soybean Pustule Pathogen (Xanthomonas axonopodis pv. glycines)

  • Lee, Sang-Hyeob;Park, Do-Il
    • The Plant Pathology Journal
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    • v.20 no.1
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    • pp.46-51
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    • 2004
  • Host resistance is usually parasite-specific and is restricted to a particular pathogen races, and commonly is expressed against specific pathogen genotypes. In contrast, resistance shown by an entire plant species to a species of pathogen is known as non-host resistance. Therefore, non-host resistance is the more common and broad form of disease resistance exhibited by plants. As a first step to understand the mechanism of non-host plant defense, expressed sequence tags (EST) were generated from a hot pepper leaf cDNA library constructed from combined leaves collected at different time points after inoculation with non-host soybean pustule pathogen (Xanthomonas axonopodis pv. Glycines; Xag). To increase gene diversity, ESTs were also generated from cDNA libraries constructed from anthers and flower buds. Among a total of 10,061 ESTs, 8,525 were of sufficient quality to analyze further. Clustering analysis revealed that 55 % of all ESTs (4685) occurred only once. BLASTX analysis revealed that 74% of the ESTs had significant sequence similarity to known proteins present in the NCBI nr database. In addition, 1,265 ESTs were tentatively identified as being full-length cDNAs. Functional classification of the ESTs derived from pathogen-infected pepper leaves revealed that about 25% were disease- or defense-related genes. Furthermore, 323 (7%) ESTs were tentatively identified as being unique to hot pepper. This study represents the first analysis of sequence data from the hot pepper plant species. Although we focused on genes related to the plant defense response, our data will be useful for future comparative studies.

In vivo Pathogenicity Test of Oak Wilt Fungus (Raffaelea quercus-mongolicae) on Oriental Chestnut Oak (Quercus acutissima)

  • Yi, Su Hee;Lee, Jin Heung;Seo, Sang Tae;Lee, Jong Kyu
    • Journal of Forest and Environmental Science
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    • v.33 no.4
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    • pp.342-347
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    • 2017
  • Since the first report of the oak wilt disease at 2004 in Korea, the disease distributed over Korean peninsula and are still giving severe damages. The management of oak wilt disease in Korea has mainly focused on the control of insect vector, Platypus koryoensis. Neverthless the effective method for evaluating the pathogenicity of the pathogen, Raffaelea quercus-mongolicae (Rqm), and for screening chemical or biological agents with strong inhibitory activity against the pathogen, is absolutely necessary, an reliable method is not available so far. This study was conducted to develop the effective method for evaluating the pathogenicity of Rqm in oak trees. The culture suspensions of Rqm were artificially injected to the saplings of Quercus acutissima by using ChemJet tree injector. Three months after treatments, the treated saplings were cut and dipped into 1% fuchsin acid solution. There were significant differences in non-conductive area (%), discoloration area (%) and vertical discoloration length between the pathogen-injected and distilled water-injected control treatments. These results indicated that the pathogen is the causal agent for the dysfunction of water conductive tissue, which will finally result in wilt symptom. Re-isolation of the pathogen and PCR detection using specific primers for the pathogen also confirmed the presence of Rqm in the sapwood chips of the pathogen-injected saplings. These observations would be greatly applied to other related researches for evaluating the pathogenicity of tree wilt pathogens and biocontrol efficacy of the selected antagonistic microorganisms, in case that the wilt symptom is not easily shown by artificial inoculation of the causal agent.

Determination of Neurotoxin Gene Expression in Clostridium botulinum Type A by Quantitative RT-PCR

  • Shin, Na-Ri;Shin, Ji-Hun;Chun, Jeong Hoon;Yoon, So-Yeon;Kim, Bong Su;Oh, Hee-Bok;Rhie, Gi-eun
    • Molecules and Cells
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    • v.22 no.3
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    • pp.336-342
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    • 2006
  • Real time reverse transcription (RT)-PCR was used to quantify the expression of the botulinum neurotoxin type A (BoNT/A) gene (cntA) by normalization with the expression of 16S rRNA. The method were confirmed by monitoring the mRNA levels of cntA during growth in five type A strains. In all but one of the strains the expression of cntA mRNA was maximal in the late exponential phase, and approximately 35-fold greater than in the early exponential phase. The concentration of the extracellular BoNT/A complex detected by ELISA was highest in stationary phase. Sodium nitrite and sorbic acid completely inhibited growth at 20 ppm and $4mg\;ml^{-1}$, respectively. CntA expression became lower in proportion to the concentration of sorbic acid, and this reduction was confirmed by mouse bioassay. Our results show that real time RT-PCR can be used to quantify levels of C. botulinum type A neurotoxin transcripts and to assess the effects of food additives on botulinal risk.

Mediating Effect of Nursing Professionalism in the Relationship between Nurse's Character and Nursing Intention Caring for High Risk Pathogen Infected Patients in the Tertiary Hospital Nurses (병원간호사의 간호인성과 고위험 병원체 감염환자 간호의도와의 관계: 간호전문직관의 매개효과)

  • Ryu, Jeong Lim;Chae, Yoon Jung;Kim, Shin Hee
    • Journal of East-West Nursing Research
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    • v.27 no.2
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    • pp.143-152
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    • 2021
  • Purpose: This study aims to explore the mediating effect of the nursing professionalism in the relationship between nurse's character and nursing intention caring for high risk pathogen infected patients in the tertiary hospital nurses. Methods: This study used a crosssectional descriptive design. The participants were 129 nurses from two tertiary hospitals. The questionnaire consisted of tools measuring clinical nursing personality, nursing professionalism and nursing intention caring for high risk pathogen infected patients in the tertiary hospital nurses. The data were analyzed using independent sample t-test, one-way ANOVA, Pearson correlation coefficient, and hierarchical multiple linear regression. Results: There were significant relationships between nurse's character and nursing professionalism (r=.59, p<.001), nurse's character and nursing intention caring for high risk pathogen infected patients (r=.54, p<.001), and nursing professionalism and nursing intention caring for high risk pathogen infected patients (r=.54, p<.001). In the relationship between nurse's character and nursing intention caring for high risk pathogen infected patients, nursing professionalism had a partial mediating effect. Conclusion: This current study suggests that strategies for improving nursing professionalism in nurses should be considered when developing an educational program for enhancing their nursing intention caring for high risk pathogen infected patients.