• Korean Journal of Veterinary Research
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• v.31 no.2
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• pp.195-199
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• 1991

Infectious pancreatic necrosis(IPN) virus was known as a causative agent of newly recognized viral disease of young rainbow trout characterized by highly contagious, high mortality and necrosis of pancreas. Several strains of IPN viruses were recovered from young rainbow trout that have been shown a typical cinical sign of infectious pancreatic necrosis disease. The field isolate produced cytopathic effect, and multiplied up to $10^{6.0}$ to $10^{6.5}$ $TCID_{50}/0.1ml$ in BT cell culture. In the indirect immunofluorescent assay with trout anti-IPN virus IgG and goat anti-trout IgG FITC conjugate, these isolates were proved to be a IPN virus that were closely related with VR277 strain of IPN virus antigenically.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.5-12
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• 2011

Infectious bursal disease (IBD) caused by infectious bursal disease virus (IBDV) is a highly contagious viral disease in chicken. It causes heavy economic loss by immune suppression and high mortality. The IBDV, designated Avibirnavirus in the Family Birnaviridae, has a double-stranded RNA genome formed by two segments, segment A and segment B. Segment A encodes a 108 KDa polypeptide that is self-cleaved to produce pVP2, VP3 and VP4, and later pVP2 is cleaved to VP2. The VP2 contains the antigenic regions responsible for elicitation of neutralizing antibodies and VP3 is a major immunogenic protein of IBDV. In this study, monoclonal antibodies (MAbs) specific for IBDV were produced and characterized. All 15 MAbs were specific for IBDV and did not react with other viruses used in this study. The protein specificity of MAbs was determined by comparing the reactivity patterns of each MAb with IBDV VP2 and VP234 recombinant baculoviruses and Western blot analysis. As a result, 7 MAbs (1F5, 2C8, 2F4, 3C7, 4C3, 6F11, 6G5) and 5 MAbs (2A4, 2G2, 3F5, 3G2, 4F10) were specific for VP2 and VP3, respectively. The protein specificity of 3 MAbs (2B8, 3F7, 3F8) were not determined. Five (2C8, 2F4, 4C3, 6F11, 6G5) of the VP2-specific MAbs had a neutralizing activity against IBDV. Some MAbs reacted with IBDV-infected bursa of Fabricius by indirect fluorescence antibody (IFA) and immunohistochemistry (IHC) assay. The MAbs produced in this study would be used for diagnostic reagents for the detection of IBDV infection.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.22-28
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• 2014

Purpose: This study aimed at determining the detection rate of respiratory viruses and at investigating the risk factors associated with respiratory virus detection in young infants. Methods: From September 2011 to August 2012, nasopharyngeal swabs were obtained from 227 infants aged ${\leq}90$ days with suspected infectious diseases, including sepsis. We performed a retrospective analysis of their clinical characteristics. The prevalence of respiratory viruses in their nasopharyngeal swabs was assayed by real-time polymerase chain reaction (real-time PCR). Results: In total, 157 (69.2%) infants had more than one of the following respiratory viruses: respiratory syncytial virus (n=75), rhinovirus (n=42), influenza virus (n=18), parainfluenza virus (n=15), human metapneumovirus (n=9), coronavirus (n=9), adenovirus (n=4), and bocavirus (n=3). During the same period, bacterial infections were confirmed in 24 infants (10.6%). The detection of respiratory viruses was significantly associated with the presence of cough, a family history of respiratory illness, and a seasonal preference (fall/winter). Using logistic regression analysis, these 3 variables were also identified as significant risk factors. During fall and winter, detection of respiratory viruses was significantly higher in infants who did not have a bacterial infection. Conclusion: Respiratory virus is an important pathogen in young infants admitted to a hospital, who are suspected with infectious diseases. Detection of respiratory viruses in young infants was associated with seasonality (fall/winter), presence of respiratory symptoms and a family history of respiratory illness.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.97-103
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• 2002

Infectious bronchitis(IB) is a viral disease in which continued evolution of the virus is of paramount importance for annual endemics and epidemics in chickens. Since the isolation of IB viruses(IBVs) in the 1930s, over 50 serotypes or variants have been reported worldwide. Continuing evolution is most prominent in the suface glycoproteins of IBV but also occurs in other parts of the genome. This genetic variability results from accumulation of molecular changes that can occur by a number of different mechanisms including genetic drift (point mutations) and genetic shift(RNA recombination). GA98 is a new serotype of IBV identified recently in the United States. In this paper, the evolutionary trend of IBV will be discussed using GA98 serotype as a model.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1074-1078
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• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• Journal of fish pathology
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• v.26 no.3
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• pp.283-287
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• 2013

The susceptibility of marine medaka, Oryzias dancena to fish pathogenic viruses (infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), hirame rhabdovirus (HIRRV), infectious hematopoietic necrosis virus (IHNV), and lymphocystis disease virus (LCDV)) was investigated. The cumulative mortalities of fish immersed with IPNV (experimental condition: $15^{\circ}C$ sea water (SW)), VHSV ($15^{\circ}C$ SW), HIRRV ($15^{\circ}C$ fresh water (FW)) were 30%, 40% and 60%, respectively. In the fish immersed with IPNV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), VHSV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), HIRRV ($15^{\circ}C$ SW), IHNV ($15^{\circ}C$ FW and SW), LCDV ($15^{\circ}C$ FW and SW, $18^{\circ}C$ FW and SW), and mock-challenged group, mortality rate was less than 10%. IPNV, VHSV and HIRRV were re-isolated from the dead fish. These results suggest that marine medaka is susceptible to IPNV, VHSV and HIRRV, although their susceptibility depends on the environmental conditions.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.93-106
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• 2023

Emerging and re-emerging zoonotic viruses become critical public health, economic, societal, and cultural burdens. The Coronavirus disease-19 (COVID-19) pandemic reveals needs for effective preparedness and responsiveness against the emergence of variants and the next virus outbreak. The targeted next-generation sequencing (NGS) significantly contributes to the acquisition of viral genome sequences directly from clinical specimens. Using this advanced NGS technology, the genomic epidemiology and surveillance play a critical role in identifying of infectious source and origin, tracking of transmission chains and virus evolution, and characterizing the virulence and developing of vaccines during the outbreak. In this review, we highlight the platforms and preparation of targeted NGS for the viral genomics. We also demonstrate the application of this strategy to take advantage of the responsiveness and prevention of emerging zoonotic viruses. This article provides broad and deep insights into the preparedness and responsiveness for the next zoonotic virus outbreak.

• Korean Journal of Veterinary Service
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• v.28 no.4
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• pp.375-385
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• 2005

The present study was conducted to investigate the genetic profile of two prevalent avian pathogens in Korea namely, Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV). Two farms located in Yeongi-gun, Chungnam were selected for this study. The two viruses were isolated from various organs (spleen, trachea, bursa of Fabricius) of deceased chickens that showed clinical symptoms of Newcastle Disease or Infectious bursal disease like swelling and congestion of the F bursa, facial edema, lacrimation, greenish yellow diarrhea as well as pathological signs like airsacculitis, haemorrhages in the intestines and so on. For analysis of NDV and IBDV, a 466 and 435 base pair fragments corresponding to the HN and VP2 regions which are highly conserved among related strains of NDV and IBDV, respectively, were amplified by RT-PCR and analyzed by sequencing. Comparison of the VP2 region showed a $99.3\%$ homology between the Korean IBDV isolate and the BJ836-attenuated vaccine strain. In contrast, the HN region of the Korean NDV isolate only has an 83 to $84\%$ homology with the vaccine strains LaSota, B1 and VGGA. Our findings reveal that the prevalent NDV strain in Korea is genetically different from the vaccine strains and may explain the recent outbreaks of Newcastle disease in the region.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.545-553
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• 1999

A 474-base pair segment covering the hypervariable region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreign very virulent(vv) IBDV strains had 94.93~100% amino acid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31~86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino acids comparing with Belgium vv IBDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all K-IBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized in a separate group which was differentiated from other compared IBDV strains.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.125-130
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• 2013

Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. Currently, two classes of anti-influenza virus drugs, M2 ion-channel inhibitors (amantadin and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir), have been used for the treatment of the influenza virus infection. Since the resistance to these drugs has been reported, the development of a new antiviral agent is necessary. In this study, we examined the antiviral efficacy of the plant extracts against the influenza A/PR/8/34 infection. In vitro, the antiviral activities of the plant extracts were investigated using the cell-based screening. Three plant extracts, Thuja orientalis, Aster spathulifolius, and Pinus thunbergii, were shown to induce a high cell viability rate after the infection with the influenza A/PR/8/34 virus. The antiviral activity of the plant extracts also increased as a function of the concentration of the extracts and these extracts significantly reduced the visible cytopathic effect caused by virus infections. Furthermore, the treatment with T. orientalis was shown to have a stronger inhibitory effect than that with A. spathulifolius or P. thunbergii. These results may suggest that T. orientalis has anti-influenza A/PR/8/34 activity.