• Pediatric Infection and Vaccine
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• 제15권2호
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• pp.138-145
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• 2008

목 적 : 소아에서 급성 위장관염을 일으키는 흔한 감염성 원인을 알아보고자 세균, 바이러스, 원충을 비교 분석하였으며, 원인체의 유무에 따라 임상양상 중증도의 차이를 연구하고자 하였다. 방 법 : 2006년 1월부터 2006년 12월까지 급성 위장 관염의 증상으로 연세대학교 원주기독병원 소아과에 입원한 15세 미만의 환아를 대상으로 하였으며, 271명의 환아에서 검체를 분석하였으며, 환아의 임상증상을 기록 하였고, Clark 점수를 통해 중증도를 분석하였다. 결 과 : 총 271명의 환아 중 137명(50.5%)에서 바이러스나 세균, 원충이 검출되었다. 바이러스는 86명(31.7%)에서 보고되었으며 rotavirus가 56명(20.6%)에서 보고되어 가장 호발하는 바이러스로 조사되었다. Norovirus는 29명(10.7%), E. coli는 35명(12.9%)에서 보고 되었다. Rotavirus에 의한 위장관염시에 구토, 설사가 빈번한 것으로 나타났다. 그러나 rotavirus를 포함한 바이러스, 세균, 원충의 양성을 보인 환아에서 Clark score는 음성을 보인 환아군과 큰 차이를 보이지 않았다. 결 론 : 소아 위장관염에서 rotavirus가 가장 흔한 바이러스로 나타났으며, 구토, 설사를 흔하게 동반한다. 그러나 rotavirus를 포함한 바이러스나 세균의 양성 여부에 따른 Clark 점수에서는 큰 차이가 없었다. 따라서 보다 객관적인 연구를 위해서는 외래환자를 포함한 대규모의 연구 및 항생제 사용 여부에 대한 고찰이 필요할 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1164-1169
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• 2008

We developed multiplex RT-PCR assays that can detect and identify 12 hemagglutinin (H1-H12) and 9 neuraminidase (N1-N9) subtypes that are commonly isolated from avian, swine, and human influenza A viruses. RT-PCR products with unique sizes characteristic of each subtype were amplified by multiplex RT-PCRs, and sequence analysis of each amplicon was demonstrated to be specific for each subtype with 24 reference viruses. The specificity was demonstrated further with DNA or cDNA templates from 7 viruses, 5 bacteria, and 50 influenza A virus-negative specimens. Furthermore, the assays could detect and subtype up to $10^5$ dilution of each of the reference viruses that had an original infectivity titer of $10^6\;EID_{50}/ml$. Of 188 virus isolates, the multiplex RT-PCR results agreed completely with individual RT-PCR subtyping results and with results obtained from virus isolations. Furthermore, the multiplex RT-PCR methods efficiently detected mixed infections with at least two different subtypes of influenza viruses in one host. Therefore, these methods could facilitate rapid and accurate subtyping of influenza A viruses directly from field specimens.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.684-692
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• 2016

Acute respiratory virus infectious diseases are a growing health problem, particularly among children and the elderly. Much effort has been made to develop probiotics that prevent influenza virus infections by enhancing innate immunity in the respiratory tract until vaccines are available. Lactobacillus plantarum GB-LP2, isolated from a traditional Korean fermented vegetable, has exhibited preventive effects on influenza virus infection in mice. To identify the molecular basis of this strain, we conducted a whole-genome assembly study. The single circular DNA chromosome of 3,284,304 bp was completely assembled and 3,250 protein-encoding genes were predicted. Evolutionarily accelerated genes related to the phenotypic trait of anti-infective activities for influenza virus were identified. These genes encode three integral membrane proteins, a teichoic acid export ATP-binding protein and a glucosamine - fructose-6-phosphate aminotransferase involved in host innate immunity, the nonspecific DNA-binding protein Dps, which protects bacteria from oxidative damage, and the response regulator of the three-component quorum-sensing regulatory system, which is related to the capacity of adhesion to the surface of the respiratory tract and competition with pathogens. This is the first study to identify the genetic backgrounds of the antiviral activity in L. plantarum strains. These findings provide insight into the anti-infective activities of L. plantarum and the development of preventive probiotics.

• 한국어병학회지
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• 제26권2호
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• pp.111-116
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• 2013

본 연구에서는 4급 암모늄에 속하는 didecyldimethylammonium chloride (DDAC)와 유카추출물 (Yucca extract)의 합제인 아쿠아 팜세이프$^{(R)}$의 어류 질병 병원체에 대한 살균효과를 확인하기 위하여 농림수산검역검사본부의 소독제 효력시험 중 세균 및 바이러스 소독제 효력시험에 따라 수행하였다. 소독제와 병원체를 증류수, 경수 그리고 유기물 조건에서 반응시킨 후, 중화액을 이용하여 중화시킨 다음, 중화된 용액을 배지 및 주화세포에서 접종시켜 세균의 성장 및 세포변성효과를 통해 소독제의 효력배수를 결정하였다. 본 연구의 결과, 아쿠아 팜세이프$^{(R)}$는 식중독을 일으키는 공시균주 살모넬라균 (S. typhimurim)에 비하여, 어병세균이 30~40배 이상 높은 희석농도에서 소독효과를 나타내었으며, VHSV에 대하여서는 2,000~3,600배의 유효한 효력배수를 나타내었다. 따라서, 향후, 야외적용시험을 통해 실제 적용에 따른 효과를 확인할 필요가 있을 것으로 사료된다.

• 한국양식학회지
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• 제16권2호
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• pp.76-83
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• 2003

본 연구에서는 상향류식 연속 역세여과 연구를 통하여 양어장 순환수 처리 후 박테리아 및 바이러스 등을 효과적으로 처리하는 기술 개발과 여과사에 금속염을 코팅시켜 생물막의 형성을 도모하는 연구를 수행하였다. 여과사를 코팅한 경우 중성 pH에서 zeta potential 양(+)이 됨을 알 수 있었고 zeta potential이 양(+)에 근접할수록 column test에서 바이러스 제거효율이 증가함을 알 수 있었다. 따라서 여과사를 금속염으로 코팅을 하는 경우가 안한 경우 보다 음이온을 띤 부유물 제거에 탁월한 효능이 있음을 보여주었다. pH에 따른 여과재료의 흡착율에서 Al coating과 Al+Fe coating은 반응 시간 30분까지 효과적으로 흡착이 일어나는 것을 볼수 있었고 이 후의 반응시간에서 파과 곡선형태를 보여주었다. 회분식 형태로 운영한 여과재료를 이용한 탈착실험에서 Non, Al, Fe및 Al+Fe coating모두에서 pH 9.95에서 용출(leaching)되는 농도가 가장 높았으며 각각의 농도는 7.47, 4.80, 20.89 및 7.23 mg/L로 각각 나타났다. 이번 연구에서 Al coating의 경우 pH에 따른 영향은 거의 나타나지 않았으며, pH가 증가함에 따라 약간 감소하는 것을 알수 있었고 Fe coating에서는 pH의 영항이 없었으며, Al+Fe coating에서는 pH가 증가함에 따라 탁도도 역시 일정하게 증가하는 것으로 나타났다.

• 한국어병학회지
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• 제36권2호
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• pp.239-250
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• 2023

최근 뱀장어 (Anguilla japonica)에서 발생하고 있는 질병을 파악하기 위하여 질병 모니터링을 실시하였다. 2021년 5월부터 2022년 3월까지는 폐사가 발생한 7개의 양만장 유래의 뱀장어를 7회 검사하였다. 모든 양만장에서 JEECV가 검출되었고 양만장마다 1-2종의 세균 (Edwardsiella anguillarum, E. piscisida, Aeromonas sp., Citrobacter freundii, Lactococcus garviae 혹은 Vibrio sp.)이 복합감염이 일어나 있었다. 2022년 3월부터 2023년 10월까지는 전라남도 영광의 한 양식장에서 매달 정기적으로 총 22회 검사를 실시하였다. JEECV가 22회 검사 중 10회 검출되었고 폐사가 발생하지 않는 시기에도 꾸준히 검출되었다. 세균으로는 E. anguillarum, C. freundii, Aeromonas sp.와 Vibrio sp가검출되었으나 E. anguillarum이 분리된 개체만이 간의 농양과 출혈 병소가 일관되게 관찰되었고 다른 세균은 임상증상이 없는 경우가 많았다. 모니터링의 결과를 종합하면 양만장에서의 폐사는 JEECV 단독감염보다는 JEECV가 세균과 복합감염일 경우에 발생하였다. 그러므로 뱀장어의 폐사를 줄이기 위해서는 JEECV와 E. anguillarum의 관리에 중점을 두고 복합감염을 줄이는 것이 중요한 것으로 생각된다.

• 한국잠사곤충학회지
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• 제17권1호
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• pp.63-68
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• 1975

Flacherie of all other silkworm diseases greatly affects cocoon crop as it is far-reaching and wide spreading. Fleacherie which kills silkworms caused by bacteria can be classified as bacterial digestive organ disease, and "Sotto" disease. Bacterial digestive organ disease is caused by the bacteria living in the silkworms alementary canal and a majority of flacherie belongs to this disease. Septicemia is caused by bacterias breeding in silkworms body fluid but its attach is comparatively limited during the larva period. "Sotto" disease is caused by eating mulberry leaves infected with bacteria which produce toxin and silkworms are intoxicated and killed by the toxin. The cause of flacherie is mainly due to a poor environment. The unclean and unsanitary silkworm rearing beds help bacterias breeding and bacteria enter silkworms body through mouth organ or skin. The present study is to investigate various causes of flacherie by means of pulverization of silkworm. Filtrated fluid is extracted by centrifuge and hypodermic of peroral inoculation-is given to young and medium silkworms of spring and autumn. The gained results of the experiment are summarized as follows： 1. Silkworms infected with flacherie were pulverized and their filtrated fluid was extracted by centrifuge and inspected under microscope to find polyhedron from the fluid. 2. The experimenting group of peroral inoculation. a) From the third day of peroral inoculation silkworms appetite generally decreased and ate less compared with the control group. b) After 7 days of the inoculation silkworms suffered from empty head, loose bowels and fainting. c) Some of the silkworms still ate but as were shown in Fig. 3 and 4 some dwarfish silkworms were found. d) There was no remarkable difference between 1st and 2nd instar inoculation groups. e) There was a tendency that the number of diseased silkworms was decerased as the increase of instars. 2. The experimental group of hypodermic inoculation a) Both of 3rd and 4th instar inoculation groups showed no remarkable singularity and the number of diseased silkworms decreased. b) The rate of diseased silkworms was comparatively low because the body fluid was acidy or toxin was hard soluble. Hypodermic inoculation could not give much harm to the silkworms compared to peroral inoculation.

• 상하수도학회지
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• 제29권6호
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• pp.633-641
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• 2015

Waterborne infectious disease is induced by several pathogenic microbes such as bacteria, viruses and protozoans, and the cases caused by viral infection is currently increasing. Water treatment process could reduce the number of virus in the water, but there were many difficulties to completely remove the virus particles from water. Therefore, the membrane separation technology which was reported to effectively remove pollutants from raw water has attracted increasing attention and demand. Since its efficiency has been introduced, demands for evaluation method toward the membrane filtration process are increasing. However, progression of the method development is slow due to the difficulties in cultivation of several waterborne viruses from animal models or cell culture system. To overcome the difficulties, we used adenovirus, one of the commonly isolated pathogenic waterborne viruses which can grow in cell culture system in vitro. The adenovirus used in this study was identified as human adenovirus C strain. The adenovirus was spiked in the raw water and passed through the microfiltration membrane produced by Econity, a Korean membrane company, and then the viral removal rate was evaluated by real-time PCR. In the results, the amount of virus in the filtered water was decreased approximately by 5 log scale. Because coagulant treatment has been known to reduce filtering function of the membrane by inducing fouling, we also investigated whether there was any interference of coagulant. In the results, we confirmed that coagulant treatment did not show significant interference on microfiltration membrane. In this study, we found that waterborne virus can be effectively removed by membrane filtration system. In particular, here we also suggest that real-time PCR method can rapidly, sensitively and quantitatively evaluate the removal rate of virus. These results may provide a standard method to qualifying membrane filtration processes.

• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1477-1482
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• 2001

Research in low cost feeds with high nutritional value and immunogenicity is important to reduce production cost and increase yields in the shrimp industry. In this study, immunostimulants of bacterial origin (peptidoglycan and lipopolysaccharides) and egg white were incorporated in shrimp diets as feed additives to determine the growth, survival and tolerance of Penaeus monodon to white spot syndrome virus (WSSV). Although the results obtained were not statistically significant (p>0.05) among the treatments, shrimp fed with bacterial additives and egg white showed higher weight gain, specific growth rate and survival than those fed on commercial shrimp diet. Shrimp fed with artificial diet showed 100% mortality when challenged with WSSV. However, shrimp fed on peptidoglycan supplemented diet had higher survival than their counterpart, whereas shrimp fed on egg white supplemented diet had a higher specific growth rate and better tolerance when challenged with WSSV. Further studies are required to determine the effectiveness and optimization of bacterial strains and egg white as feed additives to increase production and enhance the shrimp immune response to diseases.

• The Plant Pathology Journal
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• 제39권5호
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• pp.449-465
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• 2023

Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense-and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.