• Korean Journal of Microbiology
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• v.44 no.3
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• pp.178-185
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• 2008

Avian influenza virus (AIV) is recognized as key to the emergence of pandemic influenza for humans; there are growing concerns that AIV H9N2 may become more efficient to transmit to humans in the near future, since the infection of poultry with AIV H9N2 has been common in recent years. In this study, we aimed to produce antisera recognizing the HA and NA proteins of AIV H9N2. Initially, coding sequences corresponding to the N-terminal regions of the HA and NA proteins of the Korean AIV H9N2 (A/Ck/Kr/MS96/96) isolated from a domestic chicken were amplified from the genomic RNA. Following cloning of the amplified cDNA fragments into pGEX4T-1 vector, two GST-fusion proteins (GST-HAln and GST-NAn) were expressed in E. coli BL21 and purified with glutathione sepharose columns; the recombinant GST-HAln and GST-NAn proteins were both used as immunogens in rabbits. The antigenicity of the rabbit antisera was analyzed by immunoblotting of the cell lysates prepared from AIV H9N2-infected MDCK cells. Overall, the recombinant HAln and NAn proteins fused to the C-terminus of GST and the rabbit antisera raised against the corresponding recombinant proteins would provide a valuable reagent for AIV diagnosis and basic research.

• Tuberculosis and Respiratory Diseases
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• v.72 no.6
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• pp.493-500
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• 2012

Background: This study investigated the clinical characteristics and risk factors of the severity of pandemic influenza A (H1N1) 2009 infection in pediatric patients in Busan and Gyeongsangnam-do. Methods: Cases of influenza A (H1N1) 2009 in patients under the age of 18 years, confirmed by reverse transcription polymerase chain reaction, at Pusan National University Hospital and Pusan National University Yangsan Hospital from the last week of August 2009 through the last week of February 2010 were retrospectively analyzed. Results: Of the 3,777 confirmed cases of influenza A (H1N1) 2009, 2,200 (58.2%) were male and 1,577 (41.8%) were female. The average age of the patients was $8.4{\pm}4.8$ years. The total cases peaked during 44th to 46th week. Most of the patients were in the 5- to 9-year-old age group. Oseltamivir was administered to 2,959 (78.3%) of the patients. 221 patients (5.9%) were hospitalized, age an average of $6.7{\pm}4.5$ years. The average duration of hospitalization was $7.4{\pm}5.6$ days. One hundred cases (45.2%) had pneumonia. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. Children with asthma were at very high risk of hospitalization, over 20 times the non-asthmatic children (odds ratio [OR], 21.684; confidence interval [CI], 13.295~39.791). Likewise the children with neurologic deficits faced a 16 times higher risk (OR, 15.738; CI, 7.961~31.111). Ten of the patients (4.5%) were admitted to the intensive care unit, and eight (3.6%) required mechanical ventilation. Conclusion: Of the pediatric patients with pandemic influenza A (H1N1) 2009, most of the patients were in the 5- to 9-year-old age group. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. The most common complication was pneumonia. The very high risk of severe morbidity in children with asthma or neurologic disease shows the critical importance of targeted vaccine coverage, special awareness and swift care by both guardians and primary care providers.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.230-238
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• 2013

Objectives: For our survey of the incidence of influenza viruses among respiratory viral infections in Seoul, we evaluated their prevalence among infectious acute respiratory viral patients in Seoul from 2010 to 2012 through regular surveillance. Methods: For influenza virus detection, we conducted real-time PCR analyses on 2,544 throat specimens collected from patients with respiratory viral infections in Seoul between 2010 and 2012. They were collected and then tested for the presence of influenza viruses through reverse transcription (RT) - polymerase chain reaction (PCR). Results: 19.1% (486/2,544) of the throat specimens were determined to be positive for influenza viruses. The incidences of influenza viral infection in the case of respiratory viral infections through regular surveillance in Seoul were 23.0% (212/923) in 2010, 6.4% (47/738) in 2011, and 25.7% (227/883) in 2012, and 10.8% (275/2,544) of type A, and 8.3% (211/2,544) type B influenza viruses. In addition, the greatest prevalence was in the 20-49 age group (51.6% ), which shows that influenza viruses constituted a major causative agent of acute respiratory viral infections. Conclusions: The distributions of influenza viruses and the epidemiologic patterns of the viral pathogen in acute respiratory viral infectious patients may provide potentially effective data for epidemiological studies in Seoul, Korea.

• Tuberculosis and Respiratory Diseases
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• v.69 no.2
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• pp.103-107
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• 2010

Background: The aim of the present study was to evaluate whether findings on initial chest computed tomography (CT) of influenza pneumonia can help predict clinical outcome. Methods: We reviewed all adult patients admitted to the Emergency Department (ED) with a confirmed diagnosis of novel influenza A H1N1 virus (2009 H1N1) pneumonia, who underwent chest CT upon admission between Aug 26, 2009 and Jan 31, 2010. Radiologic findings were characterized by type and pattern of opacities and zonal distribution. Clinical outcome measures were intensive care unit (ICU) admission, mechanical ventilation, and inhospital death. Results: Of 59 patients diagnosed with 2009 H1N1 pneumonia, 41 (69.5%) underwent chest CT on admission into ED. Nine (22%) of these patients developed adverse clinical outcomes requiring the following treatments: 9 (22.0%) ICU admissions, 5 (12.2%) mechanical ventilation, and 3 (7.3%) inhospital deaths. Counting the number of patients with more than 4 involved lobes, the sensitivity, specificity, positive predictive value, and negative predictive value for detection of adverse clinical outcome were 67%, 84%, 55% and 80%, respectively. Conclusion: Extensive involvement of both lungs (over 4 lobes) is related to ICU admission, mechanical ventilation, and inhospital death. Initial chest CT may help predict an adverse clinical outcome of patients with 2009 H1N1 influenza pneumonia.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.704-713
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• 2014

The highly pathogenic avian influenza A (HPAI) viruses of the H5N1 subtype infect poultry and have also been spreading to humans. Although new antiviral drugs and vaccinations can be effective, rapid detection would be more efficient to control the outbreak of infections. In this study, a phage-display library was applied to select antibody fragments for HPAI strain A/Hubei/1/2010. As a result, three clones were selected and sequenced. A hemagglutinin inhibition assay of the three scFvs revealed that none exhibited hemagglutination inhibition activity towards the H5N1 virus, yet they showed a higher binding affinity for several HPAI H5N1 strains compared with other influenza viruses. An ELISA confirmed that the HA protein was the target of the scFvs, and the results of a protein structure simulation showed that all the selected scFvs bound to the HA2 subunit of the HA protein. In conclusion, the three selected scFVs could be useful for developing a specific detection tool for the surveillance of HPAI epidemic strains.

• Journal of Life Science
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• v.20 no.3
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• pp.365-373
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• 2010

To monitor newly emerged influenza virus variants and to investigate the prevalence pattern, our laboratory performed isolation of the viruses from surveillance sentinel hospitals. In the present study, we analysed influenza A/H1N1, A/H3N2, B viruses isolated in Busan during the 2006/07 and 2007/08 seasons by sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase (NA) genes. The isolates studied here were selected by the stratified random sample method from a total of 277 isolates, in which 15 were A/H1N1, 16 were A/H3N2 and 29 were B. Based on the phylogenetic tree, the HA1 gene showed that A/H1N1 isolates had a 96.7% to 97.7% homology with the A/Brisbane/59/2007, A/H3N2 isolates had a 98.4% to 99.7% homology with the A/Brisbane/10/2007, and B isolates had a 96.5% to 99.7% homology with the B/Florida/4/2006(Yamagata lineage), which are all the vaccine strains for the Northern Hemisphere in 2008~2009 season. In the case of the NA gene, A/H1N1 isolates had 97.8% to 98.5% homologies, A/H3N2 isolates had 98.9% to 99.4% homologies, and B isolates had 98.9% to 100% homologies with each vaccine strain in the 2008~2009 season, respectively. Characterization of the hemagglutinin gene revealed that amino acids at the receptor-binding site and N-linked glycosylation site were highly conserved. These results provide useful information for the control of influenza viruses in Busan and for a better understanding of vaccine strain selection.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1690-1691
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• 2011

본 논문에서는 H1N1 인플루엔자 A 바이러스(influenza A H1N1 virus) 검출을 위한 산화아연 나노구조(zinc oxide nano structure) 기반의 전기화학적 면역센서를 제작하고 그 특성을 분석하였다. H1N1 인플루엔자 A 바이러스는 빠른 전파 속도 때문에 정확하고 빠른 검출이 필요하다. 먼저, 2 $mm^2$의 표면적을 갖는 패턴된 금 전극 위에 열수방식(hydrothermal method)으로 성장시킨 산화아연 나노구조가 선택적으로 형성되도록 리프트-오프(lift-off) 방법을 사용하였다. 0.01 M phosphate buffered saline(pH 7.4)에서 2 ${\mu}g$/mL 농도의 1차 항체를 정전기력에 의해 산화아연 나노구조에 고정화한 후, 10 pg/mL ~ 5ng/mL 농도의 H1N1 항원을 적용하여 포획 항체에 결합시키고 HRP(horseradish peroxidase) 효소가 결합된 검출 항체를 항원에 결합시키는 샌드위치 ELISA법을 이용하였다. HRP와 반응하는 TMB(3,3', 5,5'-tetramethylbenzidine)와 과산화수소가 포함된 acetate buffered 용액(pH 5)을 전해질로 사용하고 순환전압전류 측정법(cyclic voltammetry)으로 센서의 특성을 분석하였다. 측정된 순환전압전류그래프(cyclic voltammogram)에서 H1N1 항원 농도 10 pg/mL ~ 5 ng/mL의 응답 전류는 276.47 ${\pm}$ 21.72 nA (평균 ${\pm}$ 표준편차, n=4) ~ 478.89 ${\pm}$ 6.21 nA로 측정되었고, logarithmic하게 증가하는 응답 전류 특성을 보였다.

• IMMUNE NETWORK
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• v.13 no.2
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• pp.70-74
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• 2013

L-ascorbic acid (vitamin C) is one of the well-known antiviral agents, especially to influenza virus. Since the in vivo antiviral effect is still controversial, we investigated whether vitamin C could regulate influenza virus infection in vivo by using Gulo (-/-) mice, which cannot synthesize vitamin C like humans. First, we found that vitamin C-insufficient Gulo (-/-) mice expired within 1 week after intranasal inoculation of influenza virus (H3N2/Hongkong). Viral titers in the lung of vitamin C-insufficient Gulo (-/-) mice were definitely increased but production of anti-viral cytokine, interferon (IFN)-${\alpha}/{\beta}$, was decreased. On the contrary, the infiltration of inflammatory cells into the lung and production of pro-inflammatory cytokines, tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-${\alpha}/{\beta}$, were increased in the lung. Taken together, vitamin C shows in vivo antiviral immune responses at the early time of infection, especially against influenza virus, through increased production of IFN-${\alpha}/{\beta}$.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.113-123
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• 2005

Avian influenza (AI) virus (AIV) is distributed worldwide and it has been isolated from various species of wild and domestic birds. AI transfers with high speed and shows diverse pathogenicity syndroms. In Korea, several low Pathogenic AIV, H9N2, have been isolated from the commercial farms with severe decrease of egg production and mortality resulted in severe economic loss since 1996. Therefore, it has been requested to develop AI vaccines to prevent clinical signs and economic losses from the field infection of AIV. To develop a killed vaccine that efficiently prevents low pathogenic AIV (H9N2), evaluation on the pathogenicity and selection of an inactivator for H9N2 is taking place and is being tested safety and immunogenicity of vaccine produced. Based on the pathogenicity test and viral reisolation test, the ADL0401 isolate is the characteristic low pathogenic AIVs and has fairly similar biologic functions compared with MS96 which is the official low pathogenic AIV (H9N2) and one of the predominant AIV isolated from poultry farms in Korea. In antigenicity tests, the ADL0401 and MS96 virus have no significant antigenic difference. In inactivation tests, the ADL0401 isolates can be easily inactivated with $0.1\%$ Formalin at $37^{\circ}C$ within 1 hour with a little decrease of HA titer. The vaccine developed in the present report has no harmful effect on bird and forms good immune capability. Therefore, the isolates, ADL0401 can be used for a killed vaccine which can reduce the clinical signs and viral shedding in the birds infected with H9N2 low pathogenic AIVs.

• Journal of Veterinary Science
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• v.24 no.6
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• pp.78.1-78.6
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• 2023

Avian-origin H3N2 canine influenza A viruses (CIVs) have become enzootic in China and Korea and have sporadically transmitted to North America, causing multiple epidemics. We isolated six CIVs in Korea from CIV-infected patients during 2014-2017 and conducted whole genome sequencing and phylogenetic analyses. Results revealed that CIVs have circulated and evolved in Korea since the early 2000s and then diversified into a new clade, probably contributing to multiple epidemics in China, the USA, and Canada. Our findings bridge an evolutionary gap for understanding the global transmission of CIVs, emphasizing the significance of continuous monitoring of CIVs.