• Clinical and Experimental Pediatrics
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• 제52권3호
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• pp.269-276
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• 2009

Viruses are the most common cause of lower respiratory tract infections (LRTIs) in infants and young children and are a major public health problem in this age group. Viruses were identified in 54.9-70.4% of hospitalized infants and children with LRTIs in Korea. The viral pathogens identified included respiratory syncytial virus (RSV) A and RSV B, influenza (Inf) A, Inf B, parainfluenza (PIV)1, PIV2, human bocavirus (hBoV), human rhinovirus (hRV), adenovirus (ADV), human metapneumovirus (hMPV), human coronavirus (hCoV)-OC 43, hCoV-229E, hCoV-NL63, hCoV-HKU1, and human enterovirus (hEV). Coinfections with ${\geq}$2 viruses were observed in 11.5-22.8% of children. The occurrence of LRTIs was the highest in the first year of life. The specific viruses are frequently associated with specific clinical syndromes of LRTIs. LRTIs caused by RSV were predominant among younger infants. hRV accounted for a larger proportion of LRTIs in young infants than ADV and hBoV. hMPV was frequently detected in children >24 months old. The number of hMPV infections peaked between February and May, whereas hRV was detected throughout the year. Thus far, hCoV is a less common respiratory pathogen in cases of ALRI and URI in Korean children.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1335-1342
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• 2020

The identification of bacterial pathogens to humans is critical for environmental microbial risk assessment. However, current methods for identifying pathogens in environmental samples are limited in their ability to detect highly diverse bacterial communities and accurately differentiate pathogens from commensal bacteria. In the present study, we suggest an improved approach using a combination of identification results obtained from multiple databases, including the multilocus sequence typing (MLST) database, virulence factor database (VFDB), and pathosystems resource integration center (PATRIC) databases to resolve current challenges. By integrating the identification results from multiple databases, potential bacterial pathogens in metagenomes were identified and classified into eight different groups. Based on the distribution of genes in each group, we proposed an equation to calculate the metagenomic pathogen identification index (MPII) of each metagenome based on the weighted abundance of identified sequences in each database. We found that the accuracy of pathogen identification was improved by using combinations of multiple databases compared to that of individual databases. When the approach was applied to environmental metagenomes, metagenomes associated with activated sludge were estimated with higher MPII than other environments (i.e., drinking water, ocean water, ocean sediment, and freshwater sediment). The calculated MPII values were statistically distinguishable among different environments (p < 0.05). These results demonstrate that the suggested approach allows more for more accurate identification of the pathogens associated with metagenomes.

• Journal of Electrochemical Science and Technology
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• 제13권4호
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• pp.431-437
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• 2022

As one of the most hazardous and deadliest pathogens, Listeria monocytogenes (LM) posed various serious diseases to the human being, thus designing effective strategy for its detection is of great significance. In this work, by preparing Ti₃C₂T_x MXenes nanoribbon (Ti₃C₂T_xR) as carrier and selecting thionine (Th) acted simultaneously as signal probe and functional monomer, a LM pathogen-imprinted polymers (PIP) integrated probe electrochemical sensor was design to monitor LM for the first time, that was carried out through the electropolymerization of Th on the Ti₃C₂T_xR/GCE surface in the existence of LM. Upon eluting the templates from the LM imprinted cavities, the fabricated PIP/Ti₃C₂T_xR/GCE sensor can rebound LM cells effectively. By recording the peak current of Th as the response signal, it can be weakened when LM cell was re-bound to the LM imprinted cavity on PIP/Ti₃C₂T_xR/GCE, and the absolute values of peak current change increase with the increasement of LM concentrations. After optimizing three key parameters, a considerable low analytical limit (2 CFU mL^-1) and wide linearity (10-10⁸ CFU mL^-1) for LM were achieved. In addition, the experiments demonstrated that the PIP/Ti₃C₂T_xR sensor offers satisfactory selectivity, reproducibility and stability.

• 대한방사선기술학회지:방사선기술과학
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• 제45권3호
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• pp.233-239
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• 2022

In the radiology department, where radiation is used in medical institutions to perform examinations with various equipment, the field of surgical treatment is the intervention angiography room. Accordingly, strict infection control is required. The purpose of this study was to determine the contamination status by detecting pathogens before and after disinfection in the intervention angiography room, and to determine the degree of death by using a disinfectant, sodium dichloride isocyanurate, which is mainly used in the intervention angiography room. The subjects were 10 medical institutions of general hospital level or higher with an intervention angiography room in the P city, and 12 places with high contact frequency during examinations and procedures were sampled and requested to an analysis institution. As for the sample collection method, up/down, left/right directions were used to increase precision. Before disinfection, all procedures were completed, and after disinfection, exposure was performed using a disinfectant for at least 10 minutes, and detection was performed using a transport medium. As a result, in the pathogen analysis, most pathogens were detected in a humid environment or in a place with high contact frequency for microorganisms to thrive. The detected pathogens were found in the general environment or were human flora. It is a pathogen that does not cause disease under normal healthy host conditions. However, it was found to be an opportunistic infection that causes opportunistic infection depending on the case or situation in which the body's resistance is weakened. In addition, as a result of using the disinfectant mainly used in the intervention angiography room, it was found that more than 93.3% of them died. Therefore, the data of this study will be used as good basic data for the evaluation of pathogens in the intervention angiography room and will be of great help in infection control.

• Pediatric Infection and Vaccine
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• 제28권2호
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• pp.92-100
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• 2021

목적: 중추신경계 감염의 적절한 치료를 위해서 신속한 원인 병원체의 확인이 중요하다. 본 연구는 열이 있는 영아의 뇌척수액 검체에서 원인 병원체 검출을 위한 BioFire^® Meningitis/Encephalitis (ME) panel 검사 방법의 진단적 가치를 평가하고자 수행되었다. 방법: 2016년 1월부터 2019년 7월까지 발열을 주소로 서울대학교 어린이병원에 내원한 90일 미만의 영아로부터 채취한 뇌척수액으로 기존검사(세균 배양, Xpert^® enterovirus assay, herpes simplex virus-1 and -2 중합효소 연쇄반응 검사)를 시행한 후 -70℃ 초저온 냉동고에 보관된 검체를 대상으로 BioFire^® ME panel 검사를 시행하였다. 결과: 총 72개 검체(원인 병원체가 검출된 24개와 검출되지 않은 48개)가 포함되었다. BioFire^® ME panel 검사 결과, 기존검사로 원인 병원체가 검출되지 않은 48개의 검체 중 41개(85.4%)는 음성이었고 원인 병원체가 검출된 24개 검체 중 22개(91.7%)가 동일한 결과(enterovirus 19개, Streptococcus agalactiae 2개, Streptococcus pneumoniae 1개)를 보여 전체 일치율은 87.5% (63/72)였다. 병원체가 기존검사에서 검출되지 않았으나 BioFire^® ME panel에서 검출된 7개의 검체 중 6개에서 human parechovirus (HPeV)가 검출되었다. 결론: 열이 있는 90일 미만 영아에서 BioFire^® ME panel 검사법은 원인 병원체가 밝혀진 기존검사 결과와는 비교적 높은 일치도를 보이며, HPeV를 추가적으로 진단할 수 있었다. 향후, 소아청소년 진료 영역에서 BioFire^® ME panel 검사법을 적용할 근거를 마련하기 위한 임상적 유용성과 비용 효과에 대한 연구가 필요하다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.60-60
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• 2015

Hybrid histidine kinase is a part of two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. In the present study, Tco1, a homologue of human pathogen Cryptococcus neoformans Tco1 encoding a hybrid histidine kinase, was identified in corn smut pathogen Ustilago maydis by bioinformatic analysis. To explore the role of Tco1 in the virulence of U. maydis, mutants in which the tco1 gene was partially deleted were constructed by allelic exchange. The U. maydis tco1 mutants did show unaltered growth rate on axenic medium but were unable to produce conjugation tubes and develop fuzzy filaments, resulting in impaired mating of compatible strains. The expression levels of prf1, pra1, and mfa1 which are involved in the pheromone pathway significantly decreased in the tco1 mutants. In inoculation tests to host, the tco1 mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that Tco1 plays important roles in sexual development and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

• Mycobiology
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• 제38권4호
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• pp.229-237
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• 2010

Members of the genus Aspergillus are the most common fungi and all reproduce asexually by forming long chains of conidiospores (or conidia). The impact of various Aspergillus species on humans ranges from beneficial to harmful. For example, several species including Aspergillus oryzae and Aspergillus niger are used in industry for enzyme production and food processing. In contrast, Aspergillus flavus produce the most potent naturally present carcinogen aflatoxins, which contaminate various plant- and animal-based foods. Importantly, the opportunistic human pathogen Aspergillus fumigatus has become the most prevalent airborne fungal pathogen in developed countries, causing invasive aspergillosis in immunocompromised patients with a high mortality rate. A. fumigatus produces a massive number of small hydrophobic conidia as the primarymeans of dispersal, survival, genome-protection, and infecting hosts. Large-scale genome-wide expression studies can now be conducted due to completion of A. fumigatus genome sequencing. However, genomics becomes more powerful and informative when combined with genetics. We have been investigating the mechanisms underlying the regulation of asexual development (conidiation) and gliotoxin biosynthesis in A. fumigatus, primarily focusing on a characterization of key developmental regulators identified in the model fungus Aspergillus nidulans. In this review, I will summarize our current understanding of how conidiation in two aspergilli is regulated.

• 대한의생명과학회지
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• 제24권1호
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• pp.1-8
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• 2018

${\mu}MT$ knockout mice are genetically deficient in the transmembrane domain of mu chain of the immunoglobulin M (IgM) heavy chain, resulting in the absence of mature B cells. ${\mu}MT$ knockout mice is an in vivo model system used to clarify the role of B cells in various diseases. Enteropathogenic Escherichia coli (EPEC) induces acute and chronic diarrheal disease, especially in children of developing countries. The formation of attaching and effacing (A/E) lesion is a prominent pathogenic factor in the intestinal epithelium of EPEC infection. The A/E lesion is modulated by genes located on the pathogenic island locus of enterocyte effacement (LEE) which encode a type III secretion system (T3SS) and A/E lesion-related effector proteins. Citrobacter rodentium is a murine pathogen utilized in studying the pathogenic mechanisms of EPEC in human infections. Citrobacter rodentium produce A/E lesion to attach to intestinal epithelium, thus providing a murine model pathogen to study EPEC. Several studies have investigated the pathogenesis of Citrobacter rodentium in the ${\mu}MT$ knockout mice. In this review, we introduce the ${\mu}MT$ murine model in the context of C. rodentium pathogenesis and describe in detail the role of B cells and antibodies in this disease.

• The Plant Pathology Journal
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• 제18권5호
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• pp.284-287
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• 2002

The antifungal activity of super reductive water (SRW) against plant pathogenic fungi was examined to extend its application to integrated pest management (IPM) for plant diseases. Diluted solutions ($\times$1/10, $\times$1/25, and $\times$1/50) of SRW inhibited fungal growth of kiwifruit soft rot pathogen, Diaporthe actinidiae, in a concentration dependent manner, When kiwifruits were inoculated on wounds with mycelium blocks, stock and diluted solutions successfully inhibited the disease development. In addition to the high pH of the SRW, fungistatic activity was also considered as the cause of the antifungal effect against the pathogen. Whereas conidial germination of Magnaporthe grisea was not affected by the diluted SRW solutions, appressorium formation was significantly inhibited in a concentration dependent manner, With little harmfulness to human health and environment SRW could be used to control plant pathogenic fungi, particularly appressorium-forming fungal pathogens.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제17권1호
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• pp.23-32
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• 2011

Recently, with the advent of high risk infectious agent such as the Ebola virus, SARS, special research facilities dealing with such dangerous pathogenic are drawing attention gradually. Especially, this kind of facilities can be called BL4(Biosafety Level 4) facility. At the moment, Korean government is going to construct BL4 institute in order to handle efficiently such kind of pathogen. However, there are no proper design guidelines for BL4 facility. This paper proposes circulation system of BL4 facility on the basis of analysis of existing BL4 guidelines of Canada, and Korean BL3 facilities. The outcomes of this study are as follows. At first, functional areas of BL4 facilities have been divided into three categories according to the hazard level ; dangerous area, transitional area, and ordinary area. Secondly, circulation system of BL4 facility has been explored as a form of diagram according to the circulating subjects. These include human, laboratory animals, hazardous pathogen, equipments and cloth. This study has some limitations in that it lacks empirical evidences and concrete SOPs(Standard Operating Procedure). Despite of some weaknesses, it is expected to give some preliminary guidelines for the design of circulation system in BL4 facilities.