The Generation of Reassortants by Genetic Reassortment between Different Serotypes of Hantaviruses

Park, Man-Seong,Chung, Dong-Hoon,Lee, Pyung-Woo The Korean Society for Microbiology 2003 Journal of Bacteriology and Virology Vol.33 No.1

Hantaviruses are negative-strand RNA viruses that contain three segmented (L/M/S) genome and belong to the genus hantavirus of the family Bunyaviridae. Due to such an unique structure of segmented RNA genome, hantaviruses have a possibility to produce reassortants that containing genomic sets mixed with different segments originated from both parental viruses during the genetic interaction. To investigate whether this phenomenon occurs in vitro, Hantaan (HTN) and Seoul (SEO) viruses were co-infected into Vero-E6 cells and virulent Maaji (MAA) virus was superinfected into avirulent Prospect Hill (PH) virus-infected Vero-E6 cells, respectively. To select only reassortants among progeny viruses, well separated plaque clones were analyzed by multiplex RT-PCR. The putative reassortant viruses detected by 1st multiplex RT-PCR were plaque-purified three times and confirmed by 2nd multiplex RT-PCR. Only 3 reassortants like HTN/HTN/SEO, SEO/HTN/HTN and SEO/HTN/SEO and only 2 reassortants like PH/MAA/MAA, MAA/MAA/PH as designated in order of L/M/S of genomic segments have been identified so far. These results indicate that genetic reassortment can be induced by mixed-infection of two more distantly related serotypes of hantavirus. Interestingly, reassortant SEO/HTN/SEO containing HTN viral M RNA segment is isolated more frequently. This implies that preferential selection of M genome segments occurred when RNA genomes were packaged into virion and also the process of packaging of RNA segments into virion is not random phenomenon. These reassortants would be helpful to know whether genetic reassortment is dependent on genetic distance between hantaviruses and which viral RNA segment plays an important role in coding for virulence marker. Therefore, genetic reassortment can be useful genetic tool to understand genetical, and biological function of hantavirus.

Generation of reassortant influenza viruses within the non-industrial poultry system

Lee, H.J.,Lee, D.H.,Lee, Y.N.,Kwon, J.S.,Lee, Y.J.,Lee, J.B.,Park, S.Y.,Choi, I.S.,Song, C.S. Elsevier Science 2012 INFECTION GENETICS AND EVOLUTION Vol.12 No.5

We compared the genetic and biologic characteristics of 35 influenza viruses of different epidemiological backgrounds in Korea, including H3N2 canine influenza virus (CIV). Phylogenetic analysis revealed that chicken adapted H9N2 viruses (A/chicken/Korea/96006/96 [CK/Kor/96006-like]) have acquired aquatic avian gene segments through reassortment, and these reassorted H9N2 viruses were more frequently detected from minor poultry species than from industrial poultry. Conversely, gene segments from CK/Kor/96006-like viruses were also detected in most of the viruses from domestic ducks. Interestingly, domestic ducks, rather than wild aquatic birds, harbored close relatives of all eight gene segments of H3N2 CIV, which preferred binding to avian receptors. Therefore, bidirectional virus transmission events are assumed to have occurred between land-based poultry and aquatic poultry, in particular within the non-industrial poultry system. These events have contributed to the generation of a novel reassortant, H3N2 CIV. To prevent generating other reassortants capable of interspecies transmission, gene movements in the non-industrial poultry systems should be clarified and managed.

Identification of Reassortant Pandemic H1N1 Influenza Virus in Korean Pigs

( Jae Yeon Han ),( Sung Jun Park ),( Hye Kwon Kim ),( Se Mi Rho ),( Giap Van Nguyen ),( Dae Sub Song ),( Bo Kyu Kang ),( Hyung Jun Moon ),( Min Joo Yeom ),( Bong Kyun Park ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.5

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.

Phylogenetic Characterization of Tomato chlorosis virus Population in Korea: Evidence of Reassortment between Isolates from Different Origins

이예지,길의준,곽해련,김미경,서장균,이석찬,최홍수 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.3

Tomato chlorosis virus (ToCV) is a whitefly-transmitted and phloem-limited crinivirus. In 2013, severe interveinal chlorosis and bronzing on tomato leaves, known symptoms of ToCV infection, were observed in greenhouses in Korea. To identify ToCV infection in symptomatic tomato plants, RT-PCR with ToCV-specific primers was performed on leaf samples collected from 11 tomato cultivating areas where ToCV-like symptoms were observed in 2013 and 2014. About half of samples (45.18%) were confirmed as ToCV-infected, and the complete genome of 10 different isolates were characterized. This is the first report of ToCV occurring in Korea. The phylogenetic relationship and genetic variation among ToCV isolates from Korea and other countries were also analysed. When RNA1 and RNA2 are analysed separately, ToCV isolates were clustered into three groups in phylogenetic trees, and ToCV Korean isolates were confirmed to belong to two groups, which were geographically separated. These results suggested that Korean ToCV isolates originated from two independent origins. However, the RNA1 and RNA2 sequences of the Yeonggwang isolate were confirmed to belong to different groups, which indicated that ToCV RNA1 and RNA2 originated from two different origins and were reassorted in Yeonggwang, which is the intermediate point of two geographically separated groups.

Novel reassortants of clade 2.3.4.4 H5N6 highly pathogenic avian influenza viruses possessing genetic heterogeneity in South Korea in late 2017

Yu-Na Lee,천선하,Soo-Jeong Kye,Eun-Kyoung Lee,Mingeun Sagong,Gyeong-Beom Heo,강용명,Hyun-Kyu Cho,Yong-Joo Kim,Hyun-Mi Kang,이명헌,Youn-Jeong Lee 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.6

Novel H5N6 highly pathogenic avian influenza viruses (HPAIVs) were isolated from duck farms and migratory bird habitats in South Korea in November to December 2017. Genetic analysis demonstrated that at least two genotypes of H5N6 were generated through reassortment between clade 2.3.4.4 H5N8 HPAIVs and Eurasian low pathogenic avian influenza virus in migratory birds in late 2017, suggesting frequent reassortment of clade 2.3.4.4 H5 HPAIVs and highlighting the need for systematic surveillance in Eurasian breeding grounds.

Phylogenetic Characterization of Tomato chlorosis virus Population in Korea: Evidence of Reassortment between Isolates from Different Origins

Lee, Ye-Ji,Kil, Eui-Joon,Kwak, Hae-Ryun,Kim, Mikyeong,Seo, Jang-Kyun,Lee, Sukchan,Choi, Hong-Soo The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.3

Tomato chlorosis virus (ToCV) is a whitefly-transmitted and phloem-limited crinivirus. In 2013, severe interveinal chlorosis and bronzing on tomato leaves, known symptoms of ToCV infection, were observed in greenhouses in Korea. To identify ToCV infection in symptomatic tomato plants, RT-PCR with ToCV-specific primers was performed on leaf samples collected from 11 tomato cultivating areas where ToCV-like symptoms were observed in 2013 and 2014. About half of samples (45.18%) were confirmed as ToCV-infected, and the complete genome of 10 different isolates were characterized. This is the first report of ToCV occurring in Korea. The phylogenetic relationship and genetic variation among ToCV isolates from Korea and other countries were also analysed. When RNA1 and RNA2 are analysed separately, ToCV isolates were clustered into three groups in phylogenetic trees, and ToCV Korean isolates were confirmed to belong to two groups, which were geographically separated. These results suggested that Korean ToCV isolates originated from two independent origins. However, the RNA1 and RNA2 sequences of the Yeonggwang isolate were confirmed to belong to different groups, which indicated that ToCV RNA1 and RNA2 originated from two different origins and were reassorted in Yeonggwang, which is the intermediate point of two geographically separated groups.

Continuing evolution of H9 influenza viruses in Korean poultry

Lee, Youn-Jeong,Shin, Jin-Young,Song, Min-Suk,Lee, Young-Min,Choi, Jun-Gu,Lee, Eun-Kyoung,Jeong, Ok-Mi,Sung, Haan-Woo,Kim, Jae-Hong,,Kwon, Yong-Kuk,Kwon, Jun-Hun,Kim, Chul-Joong,Webby, Richard J.,Webs 3M Company 2007 Virology Vol.359 No.2

<P><B>Abstract</B></P><P>We analyzed the evolution of H9 influenza viruses isolated from Korean chicken farms from 2002 to 2004. Korean H9 viruses formed two antigenically distinct groups: those isolated from 1996 to mid-2003, and those isolated from late 2003 through 2004. Most of the 2004 isolates showed greater cross-reactivity with the second group than with the first group. Phylogenetic analysis of the 12 viruses studied revealed three genotypes of H9N2 viruses and showed that reassortment had occurred. One isolate, Ck/Kor/164/04, belonged to the H9N8 subtype. Its HA and <I>PB1</I> genes were similar to those of the H9N2 viruses, but its other genes were closely related to H3N8 viruses. This report is the first (to our knowledge) of H9N8 infection in this host. The pathogenicity of the early isolates altered due to antigenic drift and reassortment, leading to H9 avian influenza viruses in Korea that potentially can expand their host range to mammalians.</P>

Virulence of a novel reassortant canine H3N2 influenza virus in ferret, dog and mice models

( Woonsung Na ),( Kwang-soo Lyoo ),( Minjoo Yeom ),( Dae-gwin Jeong ),( Daesub Song ),( Chang-ung Kim ),( Jeong-ki Kim ),( Daesub Song ) 대한인수공통전염병학회 2016 창립총회 및 학술대회 초록집 Vol.2016 No.1

The outbreak of a canine influenza virus (CIV) H3N2 reassortanted from pandemic (pdm) H1N1 and CIV H3N2 in companion animals has underscored the urgent need to monitor CIV infection for potential zoonotic transmission of influenza viruses to humans. In this study, we assessed the virulence of a novel CIV H3N2 (VC378) from a pdm H1N1 and CIV H3N2 coinfected dog in ferrets, dogs, and mice. Significantly enhanced virulence of VC378 was demonstrated in mice, although the transmissibility and pathogenicity of VC378 were similar to those of classic H3N2 in ferrets and dogs. This is notable because mice inoculated with an equivalent dose of classic CIV H3N2 showed no clinical signs and no lethality. We found that the PA and NS gene segments of VC378 were introduced from pdmH1N1, and these genes included amino acid substitutions; PAP224S and NS-I123V, that were previously found to be associated with virulence enhancement in mice. Thus, we speculate that the natural reassortment of CIV between pdm H1N1 and CIV H3N2 can confer virulence and that continuous surveillance is needed to monitor the evolution of CIV in companion animals.

Molecular Characterization and Variation of the Broad bean wilt virus 2 Isolates Based on Analyses of Complete Genome Sequences

곽해련,최홍수,김미경,이예지,서장균,김정수,김국형,차병진 한국식물병리학회 2013 Plant Pathology Journal Vol.29 No.4

The full-genome sequences of fourteen isolates of Broad bean wilt virus 2 (BBWV2), collected from broad bean,pea, spinach, bell pepper and paprika plants in Korea during the years 2006−2012, were determined and analyzed comparatively along with fifteen previously reported BBWV2 genome sequences. Sequence analyses showed that RNA-1 and RNA-2 sequences of BBWV2Korean isolates consisted of 5950-5956 and 3568-3604nucleotides, respectively. Full-length genome sequencebased phylogenetic analyses revealed that the BBWV2Korean isolates could be divided into three major groups comprising GS-I (isolates BB2 and RP7) along with isolate IP, GS-II (isolates BB5, P2, P3 and RP3)along with isolate B935, and GS-III including 16 BBWV2Korean isolates. Interestingly, GS-III appears to be newly emerged and predominant in Korea. Recombination analyses identified two recombination events in the analyzed BBWV2 population: one in the RNA-1 of isolate K and another one in the RNA-2 of isolate XJ14-3. However, no recombination events were detected in the other 21 Korean isolates. On the other hand, out of 29 BBWV2 isolates, 16 isolates were found to be reassortants,of which each RNA segment (i.e. RNA1 and RNA2) was originated from different parental isolates. Our findings suggested that reassortment rather than recombination is a major evolutionary force in the genetic diversification of BBWV population in Korea.

Evaluation of the zoonotic potential of a novel reassortant H1N2 swine influenza virus with gene constellation derived from multiple viral sources

Lee, J.H.,Pascua, P.N.Q.,Decano, A.G.,Kim, S.M.,Park, S.J.,Kwon, H.I.,Kim, E.H.,Kim, Y.I.,Kim, H.,Kim, S.Y.,Song, M.S.,Jang, H.K.,Park, B.K.,Choi, Y.K. Elsevier Science 2015 INFECTION GENETICS AND EVOLUTION Vol.34 No.-

In 2011-2012, contemporary North American-like H3N2 swine influenza viruses (SIVs) possessing the 2009 pandemic H1N1 matrix gene (H3N2pM-like virus) were detected in domestic pigs of South Korea where H1N2 SIV strains are endemic. More recently, we isolated novel reassortant H1N2 SIVs bearing the Eurasian avian-like swine H1-like hemagglutinin and Korean swine H1N2-like neuraminidase in the internal gene backbone of the H3N2pM-like virus. In the present study, we clearly provide evidence on the genetic origins of the novel H1N2 SIVs virus through genetic and phylogenetic analyses. In vitro studies demonstrated that, in comparison with a pre-existing 2012 Korean H1N2 SIV [A/swine/Korea/CY03-1½012 (CY03-1½012)], the 2013 novel reassortant H1N2 isolate [A/swine/Korea/CY0423/2013 (CY0423-12/2013)] replicated more efficiently in differentiated primary human bronchial epithelial cells. The CY0423-12/2013 virus induced higher viral titers than the CY03-1½012 virus in the lungs and nasal turbinates of infected mice and nasal wash samples of ferrets. Moreover, the 2013 H1N2 reassortant, but not the intact 2012 H1N2 virus, was transmissible to naive contact ferrets via respiratory-droplets. Noting that the viral precursors have the ability to infect humans, our findings highlight the potential threat of a novel reassortant H1N2 SIV to public health and underscore the need to further strengthen influenza surveillance strategies worldwide, including swine populations.