• The Plant Pathology Journal
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• 제28권1호
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• pp.81-86
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• 2012

We developed a reassortant RNA virus vector derived from $Cucumber$ $mosaic$ $virus$ (CMV), which has advantages of very wide host range and can efficiently induce gene silencing in a few model plants. Certain CMV isolates, however, show limited host ranges presumably because they naturally co-evolved with their own hosts. We used a reassortant comprised of two strains of CMV, Y-CMV and Gn-CMV, to broaden the host range and to develop a virus vector for virus-induced gene silencing (VIGS). Gn-CMV could infect chili pepper and tomato more efficiently than Y-CMV. Gn-CMV RNA1, 3 and Y-CMV RNA2-A1 vector were newly reconstructed, and the transcript mixture of RNA1 and 3 genomes of Gn-CMV and RNA2 genome of Y-CMV RNA2 containing portions of the endogenous phytoene desaturase (PDS) gene (CMV2A1::PDSs) was inoculated onto chili pepper (cv. Chung-yang), tomato (cvs. Bloody butcher, Tigerella, Silvery fir tree, and Czech bush) and $Nicotiana$ $benthamiana$. All the tested plants infected by the reassortant CMV vector showed typical photo-bleaching phenotypes and reduced expression levels of $PDS$ mRNA. These results suggest that the reassortant CMV vector would be a useful tool for the rapid induction of the RNA silencing of endogenous genes in chili pepper and tomato plants.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.699-707
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• 2012

Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin-Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.232-234
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• 2003

• 한국어병학회지
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• 제34권2호
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• pp.133-140
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• 2021

With the recent isolation of a new betanodavirus in shellfish, Korean Shellfish Nervous Necrosis Virus (KSNNV), it has also been identified the reassortant KSNNV of two RNA segments, in which one segment is KSNNV genotype but the other one is known genotype. In this study, we confirmed that the ressortant KSNNVs obtained in previous screening study of our laboratory for betanodaviruses in shellfish were KS/RGNNV and RG/KSNNV type by performing two consecutive multiplex RT-PCR on each RNA1 and RNA2 segment (R1- and R2-discriminative multiplex two-step RT-PCR, respectively) to determine the genotype of each segment based on the size of amplicon. In the pathogenicity analysis, none of the reassortants induced specific external symptoms or mortality of VNN, but viruses of 2 × 10⁴~10⁵ copies/mg or more were detected at 14 days after injection (10⁷ copies/fish) in brain tissues of 4 species except for crucian carp and common carp among the 6 species of juvenile fish used. In addition, the histopathological features of weak but distinct vacuole formation were also found in the brain of these infected fish, but no difference was found between the two reassortants KS/RGNNV-KG and RG/KSNNV-CM.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1017-1025
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• 2006

Hantaviruses possess three RNA segments of negative sense. Co-infection of closely related hantaviruses may result in generation of a progeny virus with genomic polyploidy, containing a partial or complete set of genome originated from more than one parental virus. To characterize the formation of viral genomic polyploidy, cultured Vero-E6 cells were co-infected with two closely related hantaviruses, Hantaan and Maaji, and the progeny viruses examined. The genotype of plaque-purified viruses was analyzed by a virus-specific RT-PCR. Seventy percent (67/96) of the progeny virus was categorized as Hantaan and 3.3% (2/96) was classified as Maaji, whereas 20% (21/96) was considered polyploidy as they contained both types of the S RNA segment. Most of the polyploidy progeny viruses were unstable and gave rise to either one of the parental viruses or a reassortant after several rounds of plaque purification. No recombination between the heterologous pair of S RNA was observed for those polyploid viruses during three consecutive plaque-to-plaque passages. These data suggest that the viral polyploidy formation constitutes a primary mechanism underlying the generation of a newly emerged hantavirus.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.135.3-136
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• 2003

In the present study, type A influenza live virus, NC-22-8, which is a combination of a cold-adapted attenuated donor virus (HTCA-A101) and a wild type virus (A/New Caledonia/20/99), was constructed and the efficacy of this new virus was assessed by immunogenicity and protection tests in the mouse model. NC-22-8 (1'$10^7, 1'10^5, 1'10^3$ pfu/mouse) was intranasally administered to mice. Four weeks later, the titers of specific IgG and haemagglutinin inhibiton (HI) were measured from blood and the titer of secretary IgA (sIgA) was also detected from boncho alveolar lavage (BAL) and mucosal fluid. (omitted)

• Journal of Veterinary Science
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• 제21권4호
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• pp.56.1-56.13
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• 2020

Background: The live bird market (LBM) plays an important role in the dynamic evolution of the avian influenza H5N1 virus. Objectives: The main objective of this study was to monitor the genetic diversity of the H5N1 viruses in LBMs in Indonesia. Methods: Therefore, the disease surveillance was conducted in the area of Banten, West Java, Central Java, East Java, and Jakarta Province, Indonesia from 2014 to 2019. Subsequently, the genetic characterization of the H5N1 viruses was performed by sequencing all 8 segments of the viral genome. Results: As a result, the H5N1 viruses were detected in most of LBMs in both bird' cloacal and environmental samples, in which about 35% of all samples were positive for influenza A and, subsequently, about 52% of these samples were positive for H5 subtyping. Based on the genetic analyses of 14 viruses isolated from LBMs, genetic diversities of the H5N1 viruses were identified including clades 2.1.3 and 2.3.2 as typical predominant groups as well as reassortant viruses between these 2 clades. Conclusions: As a consequence, zoonotic transmission to humans in the market could be occurred from the exposure of infected birds and/or contaminated environments. Moreover, new virus variants could emerge from the LBM environment. Therefore, improving pandemic preparedness raised great concerns related to the zoonotic aspect of new influenza variants because of its high adaptivity and efficiency for human infection.

• 생명과학회지
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• 제28권8호
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• pp.962-968
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• 2018

A형 인플루엔자바이러스는 야생조류에 존재하며, 사람, 돼지, 가금 및 다른 포유류등 다양한 숙주를 감염한다. 본 연구에서는, 2016년 한국 서쪽의 철새도래지에서 채취한 철새 분변에서 재조합된 새로운 H7N7 조류인플루엔자를 분리하였으며 이 바이러스의 8개 유전자를 분석하였다. 분리된 A/waterfowl/Korea/S017/2016(H7N7) 바이러스의 유전자 분석 결과 이 바이러스는 야생조류 및 가금 오리에서 유래한 조류인플루엔자로 구성된 재조합된 유전자를 가지고 있었다. 계통 분석결과 이 바이러스는 유럽과 아시아계에 속하였다. 조류인플루엔자 바이러스가 계속 진화를 하고 H7 형 조류인플루엔자는 고 병원성 조류인플루엔자로 변하여 사람과 동물에게 커다란 위협이 될 수 있기에 계속 된 역학조사가 필요하다.

• 대한임상검사과학회지
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• 제42권1호
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• pp.1-15
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• 2010

Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) is endemic in swine, and classified into influenza A and influenza C but not influenza B. Swine influenza A includes H1N1, H1N2, H3N1, H3N2 and H2N3 subtypes. Infection of SIV occurs in only swine and that of S-OIV is rare in human. What human can be infected with S-OIV is called as zoonotic swine flu. Pandemic 2009 swine influenza H1N1 virus (2009 H1N1) was emerged in Mexico, America and Canada and spread worldwide. The triple-reassortant H1N1 resulting from antigenic drift was contained with HA, NA and PB1 of human or swine influenza virus, PB2 and PA polymerase of avian influenza virus, and M, NP and NS of swine influenza virus, The 2009 H1N1 enables to transmit to human and swine. The symptoms and signs in human infected with 2009 H1N1 virus are fever, cough and sore throat, pneumonia as well as diarrhea and vomiting. Co-infection with other viruses and bacteria such as Streptococcus pneumoniae can occur high mortality in high-risk population. 2009 H1N1 virus was easily differentiated from seasonal flu by real time RT-PCR which contributed rapid and confirmed diagnosis. The 2009 H1N1 virus was treated with NA inhibitors such as oseltamivir (Tamiflu) and zanamivir (Relenza) but not with adamantanes such as amantadine and rimantadine. Evolution of influenza virus has continued in various hosts. Development of a more effective vaccine against influenza prototypes is needed to protect new influenza infection such as H5 and H7 subtypes to infect to multi-organ and cause high pathogenicity.

• 생명과학회지
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• 제33권8호
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• pp.605-611
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• 2023

최근에 재조합 H7Nx 인플루엔자 바이러스가 산발적으로 인체 감염 사례가 보고되고 있으며 이러한 바이러스는 조류 종으로부터 지속적으로 분리되고있다. 본 연구에서는 조류에서 유래된 H7N1 인플루엔자 바이러스를 분리하여 A/wild bird/South Korea/sw-anu/2023로 명명하였고, 전장유전체 분석과 분자적 특성을 분석하였다. 계통발생학적 분석 결과 A/wild bird/South Korea/sw-anu/2023는 유라시아 혈통에 속하는 H7N1 인플루엔자 바이러스로 확인되었다. A/wild bird/South Korea/sw-anu/2023 바이러스의 polymerase basic 1(PB)2, PB1, polymerase acidic (PA), nucleoprotein (NP) 유전자는 야생 조류에서 분리되었던 조류 인플루엔자 바이러스유전자와 밀접한 관련이 있는 것으로 밝혀졌으며, hemagglutinin (HA), neuraminidase (NA), matrix (M), nonstructural (NS) 유전자는 집오리에서 분리되었던 조류 인플루엔자 바이러스와 유사하였다. 이러한 결과는 동아시아-호주 이동 경로를 따라 이동하는 야생 조류들 사이에서 새롭게 유전자가 재배열된 재조합 H7N1 조류 인플루엔자 바이러스가 순환되고 있음을 시사하고 있다. 따라서, H7Nx 인플루엔자 바이러스는 전 세계적으로 순환하며, 돌연변이된 H7N1 조류 인플루엔자 바이러스는 인간을 감염시킬 수 있으므로 야생 조류 및 가금류에서 H7N1 조류 인플루엔자 바이러스의 지속적인 감시가 필요할 것이다.