• Pediatric Infection and Vaccine
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• v.30 no.2
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• pp.62-72
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• 2023

Purpose: A change is expected in the pattern of respiratory viruses including human coronavirus (HCoV) after the coronavirus disease 2019 (COVID-19) outbreak. Accordingly, identifying the distribution of respiratory viruses before the COVID-19 outbreak is necessary. Methods: We retrospectively analyzed the results of samples of nasal swabs collected from children under aged ≤18 years who were hospitalized at Myongji Hospital, Gyeonggi-do due to acute respiratory infections from 2017 to 2019. Viruses were detected by real-time reverse transcription polymerase chain reaction (RT-PCR). Results: Out of 3,557 total patients, 3,686 viruses were detected with RT-PCR including coinfections. Of the 3,557 patients, 2,797 (78.6%) were confirmed as PCR-positive. Adenovirus and human rhinovirus (hRV) were detected throughout the year, and human enterovirus was most detected during summer. Respiratory syncytial virus, influenza virus, and HCoV were prevalent in winter. In patients with croup, parainfluenza virus was most frequently detected, followed by hRV and HCoV. The PCR positive rate in summer and winter differed significantly. Conclusions: Respiratory virus patterns in northwestern Gyeonggi-do were not much different from previously reported data. The data reported herein regarding respiratory virus epidemiological information before the COVID-19 outbreak can be used for use in comparative studies of respiratory virus patterns after the COVID-19 outbreak.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.90-91
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• 2006

To reduce the economic impact and control Low pathogenic avian influenza (LPAI), vaccination with inactivated vaccine has been considered in this country. We tried to develop inactivated vaccine with reassorted H9N3 AI virus which has different type of neuraminidase compare to those of field AI virus. Before reassorted vaccine was produced, we confirm the virus as master seed by limiting dilution, RT-PCR and sequencing method. Also, we evaluate the biological characteristics of the virus to find out the possibility of prevention against field infection of AI virus. Finally, we evaluate the safety and efficacy of the vaccine made of reassorted AI virus in the specific pathogen free (SPF) chickens. After limiting dilution, we choose RV7CE4 as a vaccine candidate and compare the gene sequence of this vaccine strain to those of AI05GA which is parents strain. Compared to amino acid sequences of specific gene of AI05GA and RV7CE4, exhibited a high degree of amino acid sequence homology. In the safety and efficacy test, there were no specific clinical signs or mortality. Reassorted H9N3 viruses were reisolated in cloaca swab on 5 days post inoculation. In the vaccine study, once or twice vaccination was performed and challenged with H9N2 field virus (01310). Vaccine has no adverse effect on birds and formed good immune capability which reduce viral shedding in the birds infected with 01310. Based on the above result, we developed reassorted H9N3 vaccine which will efficiently prevent the low pathogenic AIV (H9N2) infection in the poultry farms.

• Clinical and Experimental Pediatrics
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• v.57 no.1
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• pp.29-34
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• 2014

Purpose: In this study, we aimed to investigate the prevalence of year-round respiratory viral infection in children with lower respiratory tract infection (LRTI) and the relationship between respiratory viral infection and allergen sensitization in exacerbating asthma. Methods: We investigated the sources for acute LRTIs in children admitted to our hospital from May 2010 to April 2011. The 6 most common respiratory viruses were isolated from nasopharyngeal aspirate using multiplex reverse transcription-polymerase chain reaction in 309 children; respiratory syncytial virus (RSV), adenovirus (AV), parainfluenza virus (PIV), influenza virus (IFV), human metapneumovirus (hMPV), rhinovirus (RV). Atopic sensitization was defined if more than 1 serum specific Immunoglobulin E level measured using UniCAP (Pharmacia) was over 0.35 IU/mL. Results: RSV was the most common pathogen of bronchiolitis in hospitalized children through the year. RV or IFV infection was more prevalent in asthma exacerbations compared to other LRTIs. AV and hMPV were more likely to cause pneumonia. RV and IFV were associated with asthma exacerbations in children with atopic sensitization, but not in nonatopic children. Conclusion: RV and IFV are associated with hospitalization for asthma exacerbation in children with atopic sensitization.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.333-340
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• 2013

Canine influenza virus (CIV) is an emerging pathogen that causes severe and acute respiratory disease in dogs. In 2006, the H3N2 CIV was first identified in dogs from Guangdong province in China. The nine isolates were grouped together with the canine H3N2 viruses isolated from dogs and cats in Korea. The possible interspecies transmission of influenza A virus is very important. We carried out a serological retrospective study using invited canine serum. The hospital invited 123 dogs, first vaccination group were revealed with CIV antibody positive rate of 81.8%. the second vaccination group were detected a positive rate of 91.2%. Antibody generation rate was higher in 3~10 years dogs. Protective antibody titers were detected from 2 weeks to 12 months. thereafter below the protective antibody. The results indicate that H3N2 CIV may have been consistently circulating in dog populations. Recently. These findings showed that H3N2 CIV has the capacity to replicate in and transmit among cohoused dogs and underscore the need for continued public health surveillance. Considering the result continuous management and prevention system against CIV is required at the concentrated animal care centers. The importance of CIV surveillance in this region for understanding the genesis of this virus, and it is important to remain aware of the potential of H3N2 CIV to be transmitted from dogs to the human population.

• Mycobiology
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• v.47 no.2
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• pp.256-260
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• 2019

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1-5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2-5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the $IC_{50}$ values of 30.9, 41.8, and $35.7{\mu}M$ for 3 and 46.5, 50.4, and $29.9{\mu}M$ for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.135-144
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• 2019

Low pathogenic avian influenza (LPAI; H9N2) and Newcastle disease (ND) are economically important poultry diseases in Korea. In this study, we investigated pathological features and virus distribution in the lymphoid tissues of chicks experimentally infected with H9N2 and/or ND virus. Six-weeks-old SPF chickens were divided into 4 groups, Control (C), H9N2 (E1), NDV (E2), and H9N2+NDV (E3). E1 group was challenged with 0.1 ml A/Kr/Ck/01310/01 (H9N2) $10^{5.6}$ $EID_{50}$ intranasally, E2 group was challenged with 0.5 ml KJW (NDV) $10^{5.0}{\sim}10^{6.0}$ $ELD_{50}$ intramuscularly, and E3 group was challenged with H9N2, followed 7 days later by NDV. In histopathological examination, E1 group showed depletion and necrosis in bursa of Fabricius, thymus, cecal tonsil, and spleen, whereas E2 and E3 groups were noted severe lymphocyte depletion and necrosis with destruction of lymphoid organs structures. In TUNEL assay, apoptotic bodies were detected in lymphoid organs of all experimental groups, which was most severe in E3 group. H9N2 and ND viruses were predominantly detected in cecal tonsil of E1, E2, and E3 groups by PCR and immunohistochemistry (ICH). In conclusion, co-infection of H9N2 with NDV caused severe pathologic lesions and apoptosis in lymphoid tissues compared to single infections.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.13.1-13.11
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• 2023

Background: Highly pathogenic avian influenza viruses (HPAIVs) is an extremely contagious and high mortality rates in chickens resulting in substantial economic impact on the poultry sector. Therefore, it is necessary to elucidate the pathogenic mechanism of HPAIV for infection control. Objective: Gene set enrichment analysis (GSEA) can effectively avoid the limitations of subjective screening for differential gene expression. Therefore, we performed GSEA to compare HPAI-infected resistant and susceptible Ri chicken lines. Methods: The Ri chickens Mx(A)/BF2(B21) were chosen as resistant, and the chickens Mx(G)/BF2(B13) were selected as susceptible by genotyping the Mx and BF2 genes. The tracheal tissues of HPAIV H5N1 infected chickens were collected for RNA sequencing followed by GSEA analysis to define gene subsets to elucidate the sequencing results. Results: We identified four differentially expressed pathways, which were immune-related pathways with a total of 78 genes. The expression levels of cytokines (IL-1β, IL-6, IL-12), chemokines (CCL4 and CCL5), type interferons and their receptors (IFN-β, IFNAR1, IFNAR2, and IFNGR1), Jak-STAT signaling pathway genes (STAT1, STAT2, and JAK1), MHC class I and II and their co-stimulatory molecules (CD80, CD86, CD40, DMB2, BLB2, and B2M), and interferon stimulated genes (EIF2AK2 and EIF2AK1) in resistant chickens were higher than those in susceptible chickens. Conclusions: Resistant Ri chickens exhibit a stronger antiviral response to HPAIV H5N1 compared with susceptible chickens. Our findings provide insights into the immune responses of genetically disparate chickens against HPAIV.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.245-250
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• 2019

Newcastle disease (ND) is an infectious poultry disease that caused high mortality and reduced egg production. NDVs are regularly present in the domestic duck population. And ducks play a possible role in the maintenance and transmission of NDVs. While we were monitoring the Avian Influenza, NDVs were isolated from field samples by accident. So we analysed the biological and genetic characteristics of these viruses. Lentogenic NDVs were isolated from two farms among twenty breeder duck farms. The ages of ducks were 39 weeks old in the 'A' farm and 3~72 weeks old in the 'B' farm. And they were not inoculated with the NDVs vaccine. In the biological characteristics, the both viruses which separated from the farm 'A' and 'B' were thermostable. The amino acid sequence of a site from 112 to 119 in the fusion (F) protein was 'GKQGRLIG' which has monobasic motif in the samples of both farms. And this means the separated NDVs are lentogenic. Phylogenetic analysis was performed by entire nucleotide sequence of F protein. The virus strains from the A farm (MN095239) and the B farm (MN095240) belonged to class II genotype I. Using the analysis of whole F protein nucleic acid sequence, the MN095239 (GenBank) had homology with Ulster strain about 99.95% and the MN095239 (GenBank) had homology with KR/CK/KU_LBM255/09 strain about 99.89%. NDV surveillance is needed to investigate epidemiological relationship of domestic breeder duck isolates in Korea.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.373-379
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• 2010

Purpose : This study was performed to investigate the epidemiologic and clinical features of 13 respiratory viruses in children with acute lower respiratory tract infections (ALRIs). Methods : Nasopharyngeal aspirates were prospectively obtained from 325 children aged 15 years or less from May 2008 to April 2009 and were tested for the presence of 13 respiratory viruses by multiplex real-time-polymerase chain reaction (RT-PCR). Results : Viruses were identified in 270 children (83.1%). Co-infections with ${\geq}2$ viruses were observed in 71 patients (26.3 %). Respiratory syncytial virus (RSV) was the most common virus detected (33.2%), followed by human rhinovirus (hRV) (19.1%), influenza virus (Flu A) (16.9%), human metapneumovirus (hMPV) (15.4%), parainfluenza viruses (PIVs) (8.3%), human bocavirus (hBoV) (8.0%), adenovirus (ADV) (5.8%), and human coronavirus (hCoV) (2.2%). Clinical diagnoses of viral ALRIs were bronchiolitis (37.5%), pneumonia (34.5%), asthma exacerbation (20.9%), and croup (7.1%). Clinical diagnoses of viral bronchiolitis and pneumonia were frequently demonstrated in patients who tested positive for RSV, hRV, hMPV, or Flu A. Flu A and hRV were most commonly identified in children older than 3 years and were the 2 leading causes of asthma exacerbation. hRV C was detected in 14 (4.3%) children, who were significantly older than those infected with hRV A ($mean{\pm}SD$, $4.1{\pm}3.5$ years vs. $1.7{\pm}2.3$ years; P =0.009). hBoV was usually detected in young children ($2.3{\pm}3.4$ years) with bronchiolitis and pneumonia. Conclusion : This study described the features of ALRI associated with 13 respiratory viruses in Korean children. Additional investigations are required to define the roles of newly identified viruses in children with ALRIs.