• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.399-407
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• 2007

Cause of high lethality and dissemination to human being, new development of rapid method for the detection of highly pathogenic Avian Influenza Virus (AIV) is still necessary. For the detection of AIV subtype H5N1, typical pathogenic AIV, new method to confirm sub-typing of this virus is also needed. For the purpose of ultra-rapid detection and sub-typing of hemagglutinin and neuraminidase of AIV, this study was planned. As the results we could demonstrate an ultra-rapid multiplex real-time PCR (URMRT PCR) for the detection of AIV In this study, the URMRT PCR were optimized with synthesized AIV H5- and AIV Nl-specific DNA templates and GenSpector TMC, which is a semiconductor process technology based real-time PCR system with high frequencies of temperature monitoring. Under eight minutes, the amplifications of two AIV subtype-specific PCR products were successfully and independently detected by 30 cycled ultra-rapid PCR, including melting point analysis, from $1{\times}10^3$ copies of mixed template DNA. The URMRT PCR for the detection of AIV H5N 1 developed in this study could be expected to apply not only detections of different AIVs, but also various pathogens. It was also discussed that this kind of the fastest PCR based detection method could be improved by advance of related technology in near future.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.340-344
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• 2007

Avian influenza viruses cause a considerable threat to humans and animals. In this study, we investigated whether alkaline disinfectant solution can inactivate H5N1, H3N2, H6N1, and H9N2 subtypes of avian influenza virus. When H5N1, H3N2, H6N1, and H9N2 avian influenza viruses were treated with alkaline solution diluted with PBS (pH 7.2) prior to infection into MDCK cells, alkaline disinfectant solution (at dilutions up to $10^{-2}$) completely inactivated all avian influenza subtypes tested. To confirm the inactivation of avian influenza viruses by alkaline disinfectant solution, we used an immunofluorescence assay with influenza A anti-nucleoprotein antibody and FITC-labeled secondary antibody to stain MDCK cells infected with avian H9N2 influenza viruses. No staining was observed in MDCK rells infected with H9N2 viruses that were pre-treated with a $10^{-2}$ dilution of alkaline disinfectant solution, while strong staining was observed in MDCK cells infected with H9N2 viruses without pre-treatment. Our results indicate that alkaline solution could help to control avian influenza viruses including the highly pathogenic H5N1 subtype.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.405-408
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• 2011

Purpose: In autumn 2009, the swine-origin influenza A (H1N1) virus spread throughout South Korea. The aims of this study were to determine the clinical characteristics of children infected by the 2009 H1N1 influenza A virus, and to compare the rapid antigen and realtime polymerase chain reaction (PCR) tests. Methods: We conducted a retrospective review of patients ${\geq}18$ years of age who presented to Soonchunhyang University Hospital in Seoul with respiratory symptoms, including fever, between September 2009 and January 2010. A real-time PCR test was used to definitively diagnose 2009 H1N1 influenza A infection. Medical records of confirmed cases were reviewed for sex, age, and the time of infection. The decision to perform rapid antigen testing was not influenced by clinical conditions, but by individual factors such as economic conditions. Its sensitivity and specificity were evaluated compared to real-time PCR test results. Results: In total, 934 patients tested positive for H1N1 by real-time PCR. The highest number of patients (48.9%) was diagnosed in November. Most patients (48.2%) were aged between 6 and 10 years. Compared with the H1N1 real-time PCR test results, the rapid antigen test showed 22% sensitivity and 83% specificity. Seventy-eight patients were hospitalized for H1N1 influenza A virus infection, and fever was the most common symptom (97.4%). Conclusion: For diagnosis of 2009 H1N1 influenza A virus infection, the rapid antigen test was inferior to the real-time PCR test in both sensitivity and specificity. This outcome suggests that the rapid antigen test is inappropriate for screening.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.449-454
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• 2004

Ninety pigs under the age of 120-day-old requested at the diagnostic laboratory of animal diseases in Cheju National University were evaluated for the prevalence of tissue antigen and serum antibody to swine influenza virus (SIV). For histopathologic examination there was sampled at the consolidated area in cranioventral or dorsocaudal lobes of lungs. Lung tissues from all pigs were tested for the antigen of SIV type A by immunohistochemistry (IHC). Sera from 56 pigs were used for the antibody detection to SIV type A (subtype H1N1 and H3N2) by haemagglutinin inhibition test. Pneumonic lesions were observed in 72 cases (80%) of 90 pigs. Broncho-interstitial or interstitial pneumonia were more prevalent than suppurative or fibrinous bronchopneumonia. According to HI test, 46.4% of the tested sera showed seropositive. Positive sera were consisted with 5.3% for SIV H1N1, 28.6% for SIV H3N2, and 12.5% for both subtype to be tested, respectively. SIV antigens were detected in 51 cases(56.6%) of 90 pigs. Most SIV antigens were presented in the epithelium of the bronchi and bronchiole. Necrotizing bronchitis or bronchiolitis were observed in 28(31.1%) cases of all inspected pigs. These results suggested that SIV might be an important role to induce swine pneumonia in Jeju. Also IHC was very useful for the detection of SIV in the lung.

• Tuberculosis and Respiratory Diseases
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• v.68 no.6
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• pp.350-353
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• 2010

Here we report the first fatality caused by H1N1 influenza virus infection with acute respiratory distress syndrome in Korea. A 55-year-old man presented at our emergency department with dyspnea, fever, diffuse myalgia and malaise. Bilateral lung air-space consolidation was detected on his initial chest radiograph combined with severe hypoxemia. He was supported by mechanical ventilation and treated with antibiotics. A nasopharyngeal aspirate was positive for influenza A rapid antigen and oseltamivir was started on day 3 of admission. The nasal swab sample was positive for influenza H1N1 virus by real-time reverse-transcriptase polymerase chain reaction. Despite aggressive treatment, he had refractory hypoxemia and uncontrolled septic shock. On day 5 of admission he went into cardiac arrest and expired.

• Korean Journal of Veterinary Research
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• v.52 no.4
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• pp.223-230
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• 2012

The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) (01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.

• Tuberculosis and Respiratory Diseases
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• v.70 no.3
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• pp.247-250
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• 2011

The pandemic (H1N1) 2009 influenza outbreak coincided with the typical Scrub typhus season, which can lead to diagnostic difficulties due to their similar and non-specific symptoms. Here we describe a case of laboratory confirmed co-infection of Pandemic (H1N1) 2009 influenza and Scrub typhus and discuss the difficulties in distinguishing the two illnesses clinically.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.151-159
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• 2016

Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 μg/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections.

• Tuberculosis and Respiratory Diseases
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• v.69 no.1
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• pp.24-30
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• 2010

Background: A novel 2009 influenza A (H1N1) virus emerged and disseminated to all over the world. There are few reports on the clinical characteristics of patients with complications. We describe the clinical features of pneumonia in adult patients hospitalized, who have novel influenza infection. Methods: There were 43 adult patients enrolled into the study with pneumonia of 528 hospitalized patients confirmed influenza A (H1N1) virus infection by real-time reverse transcriptase polymerase chain reaction testing, between 24 August 2009 and 31 January 2010. The clinical data of patients with pneumonia were collected retrospectively. Results: There were 22 of 43 (51.2%) influenza patients with pneumonia that had higher risk factors for complications. Compared to 28 patients with influenza A (H1N1) viral pneumonia and 15 patients, who had isolated bacteria from cultures, those with mixed viral and bacterial pneumonia were significantly more likely to have unilobar consolidations on chest radiographs (53.3 vs. 10.7%, p<0.01) and higher scores of pneumonia severity index (PSI; 90 [66~100] vs. 53 [28~90], p=0.04). Six patients required mechanical ventilation support in an Intensive Care Unit and were more likely to have dyspnea (83.3 vs. 29.3%, p=0.02) and low levels of $PaO_2$ (48.3 [37.0~70.5] vs 64.0 [60.0~74.5] mm Hg, p=0.02) and high levels of pneumonia severity index (PSI) score (108.0 [74.5~142.8] vs. 56.0 [40.5~91.0], p=0.03). Conclusion: The majority of pneumonia patients infected with novel influenza improved. Chest radiographic findings of unilobar consolidations suggest that mixed pneumonia is more likely. Initial dyspnea, hypoxemia, and high levels of PSI score are associated with undergoing mechanical ventilation support.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.107-116
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• 2015

In this study, we developed a rapid, sensitive and specific reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) assay for detection of swine influenza viruse (SIV) including major subtypes of swine influenza viruses H1N1, H1N2 and H3N2, and a novel subtype of influenza A virus that accidentally infected in pig population. The RT-LAMP was completed in 40 min at $58^{\circ}C$ and the sensitivity of the RT-LAMP ($1copy/{\mu}L$) was 10-fold higher than conventional reverse transcription-polymerase chain reaction (RT-PCR) ($10copy/{\mu}L$) and the same to real time RT-PCR ($1copy/{\mu}L$). Also, the result of the RT-LAMP can be confirmed without any detection system. Therefore, the RT-LAMP could be a alternative diagnostic method for SIV detection in national SIV monitoring system and clinical diagnostic laboratory in the future.