• Journal of Microbiology and Biotechnology
• /
• 제18권6호
• /
• pp.1164-1169
• /
• 2008

We developed multiplex RT-PCR assays that can detect and identify 12 hemagglutinin (H1-H12) and 9 neuraminidase (N1-N9) subtypes that are commonly isolated from avian, swine, and human influenza A viruses. RT-PCR products with unique sizes characteristic of each subtype were amplified by multiplex RT-PCRs, and sequence analysis of each amplicon was demonstrated to be specific for each subtype with 24 reference viruses. The specificity was demonstrated further with DNA or cDNA templates from 7 viruses, 5 bacteria, and 50 influenza A virus-negative specimens. Furthermore, the assays could detect and subtype up to $10^5$ dilution of each of the reference viruses that had an original infectivity titer of $10^6\;EID_{50}/ml$. Of 188 virus isolates, the multiplex RT-PCR results agreed completely with individual RT-PCR subtyping results and with results obtained from virus isolations. Furthermore, the multiplex RT-PCR methods efficiently detected mixed infections with at least two different subtypes of influenza viruses in one host. Therefore, these methods could facilitate rapid and accurate subtyping of influenza A viruses directly from field specimens.

• Clinical and Experimental Pediatrics
• /
• 제46권10호
• /
• pp.1024-1028
• /
• 2003

저자들은 인플루엔자 유행시기에, 생후 3년 1개월 환아에서 갑작스런 고열을 동반한 경련 발작과 의식소실을 주소로, 6일간 입원 치료에도 불구하고 급격한 급성 뇌증의 악화와 간기능수치 증가 및 신장기능 부전, 범발성 혈관내 응고증으로 사망한 남아에서 인플루엔자 바이러스 항체 검사상 A/H1N1에 대한 HI titer가 초 회 항체 역가의 4배 이상 증가됨을 관찰하여 국내에는 보고된 예가 없는 급성 인플루엔자 뇌증으로 진단한 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Journal of Veterinary Science
• /
• 제25권2호
• /
• pp.20.1-20.15
• /
• 2024

Background: Avian influenza (AI) is a contagious disease that causes illness and death in poultry and humans. High pathogenicity AI (HPAI) H5N6 outbreaks commonly occur in Quang Ninh province bordering China. In June 2021, the first HPAI H5N8 outbreak occurred at a Quang Ninh chicken farm. Objectives: This study examined the risk factors associated with HPAI H5N6 and H5N8 outbreaks in Quang Ninh. Methods: A retrospective case-control study was conducted in Quang Ninh from Nov 2021 to Jan 2022. The cases were households with susceptible poultry with two or more clinical signs and tested positive by real-time reverse transcription polymerase chain reaction. The controls were households in the same village as the cases but did not show clinical symptoms of the disease. Logistic regression models were constructed to assess the risk factors associated with HPAI outbreaks at the household level. Results: There were 38 cases with H5N6 clade 2.3.4.4h viruses (n = 35) and H5N8 clade 2.3.4.4b viruses (n = 3). Compared to the 112 controls, raising poultry in uncovered or partially covered ponds (odds ratio [OR], 7.52; 95% confidence interval [CI], 1.44-39.27), poultry traders visiting the farm (OR, 8.66; 95% CI, 2.7-27.69), farms with 50-2,000 birds (OR, 3.00; 95% CI, 1.06-8-51), and farms with ≥ 2,000 birds (OR, 11.35; 95% CI, 3.07-41.94) were significantly associated with HPAI outbreaks. Conclusions: Combining biosecurity measures, such as restricting visitor entry and vaccination in farms with more than 50 birds, can enhance the control and prevention of HPAI in Quang Ninh and its spread across borders.

• Journal of Veterinary Science
• /
• 제24권6호
• /
• pp.78.1-78.6
• /
• 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.

• 미생물학회지
• /
• 제44권3호
• /
• pp.178-185
• /
• 2008

조류 독감바이러스(avian influenza virus, AIV)는 사람에게서 발생하는 인플루엔자 대유행에 중요한 역할을 한다. 특히 최근 AIV H9N2형에 의한 가금류 감염이 빈번히 나타나고 있어 인체 감염이 상당히 우려되는 실정이다. 본 연구에서는 최종적으로 AIV의 HA와 NA 단백질에 특이적으로 반응하는 항혈청을 생산하고자 하였다. 먼저 감염된 닭에서 분리된 AIV H9N2 한국분리주 A/Ck/Kr/MS96/96의 게놈RNA로부터 RT-PCR 방법으로 HA와 NA 단백질 N-말단부위에 해당하는 염기서열을 증폭하였다. 이렇게 증폭된 DNA단편은 E. coli 발현벡터 pGEX4T-1에 삽입한 후, BL21 세포에서 각각의 GST fusion protein (GST-HAln와 GST-NAn) 형태로 발현하였다. GST-HAln와 GST-NAn은 모두 glutathione sepharose column을 사용하여 분리 및 정제하였으며, 정제된 단배질을 항원으로 사용하여 토끼 항혈청을 생산하였다. 생산된 항혈청의 항원특이성은 AIV H9N2 한국분리주 A/Ck/Kr/MS96/96로 감염된 MDCK 세포의 cell extract를 사용하여 immunoblotting을 수행함으로써 확인하였다. 본 실험결과AIV H9N2의 HA와 NA단백질 N-말단부위에 해당하는 재조합GST fusion protein과, 이들 각각의 단백질에 특이적으로 반응하는 항혈청은 앞으로AIV 감염의 진단 뿐만 아니라, AIV에 대한 기초연구에 중요한 재료로 사용될 것으로 기대한다.

• 대한수의학회지
• /
• 제47권4호
• /
• pp.399-407
• /
• 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.

• 대한수의학회지
• /
• 제53권4호
• /
• pp.193-197
• /
• 2013

Avian influenza viruses (AIV) have been isolated from a wide range of domestic and wild birds. Wild birds, predominantly ducks, geese and gulls form the reservoir of AIV in nature. The viruses in wild bird populations are a potential source of widespread infections in poultry. Active surveillance for AIV infection provides information regarding AIV distribution, and global AIV surveillance can play a key role in the early recognition of highly pathogenic avian influenza (HPAI). Since 2003 in Korea, there have been four H5N1 HPAI outbreaks caused by clade 2.5, 2.2 and 2.3.2. Therefore, improvement of AIV surveillance strategy is required to detect HPAI viruses effectively. This article deals with the major events establishing the role of wild birds in the natural history of influenza in Korea. We highlighted the need for continuous surveillance in wild birds and characterization of these viruses to understand AIV epidemiology and host ecology in Korea.

• 통합자연과학논문집
• /
• 제4권4호
• /
• pp.273-277
• /
• 2011

It's a threat for the public health that H1N1 (Influenza virus A) causes disease and transmits among humans. WHO (world health organization) declared that the infections caused by the new strain had reached pandemic proportions. The approved neuraminidase inhibitors (Zanamivir and Oseltamivir) and related investigative drug (BCX-1812) are potent, specific inhibitors of influenza A and B viruses. These drugs are highly effective to prevent influenza A and B infections. Early therapeutic use reduces illness duration and respiratory complications. Recently, we found one of the potent inhibitor of erystagallin A ($IC_{50}$ of 2.04 ${\mu}M$) for neuraminidase target, this inhibitor shows most similar structure to its natural substrate, sialic acid. Therefore, we chose 1l7f to get the receptor structure for docking study among many crystal structures. A docking study has been performed in Surflex-Dock module in SYBYL 8.1. In the present study, we attempt to compare the docking studies of pterocarpin and erystagallin A with neuraminidase receptor structure. In the previous report, the methoxy group of pterocarpin had H-bonding with Arg residues. The present docking results for erystagallin A showed the backbone of hydroxyl group shows significant H-bonding interactions with Arg152 and Arg292. The results showed that erystagallin A interacts more favorably with distinctive binding site rather than original active site. Therefore, we tried to reveal plausible binding mode and important amino acid for this inhibitor using docking and site id search calculations of Sybyl. The results obtained from this work may be utilized to design novel inhibitors for neuraminidase.

• Clinical and Experimental Pediatrics
• /
• 제56권1호
• /
• pp.42-44
• /
• 2013

Neurological complications associated with 2009 H1N1 infection in children have been reported and recognized worldwide. The most commonly reported neurological complications are seizures and encephalopathy. Secondary movement disorders are also associated with the infection, but such cases are rarely reported. Here, we describe the case of a 14-year-old boy with paroxysmal kinesigenic dyskinesia secondary to 2009 H1N1 infection, who presented with dystonia and choreic movement triggered by sudden voluntary movement.

• Journal of Microbiology and Biotechnology
• /
• 제24권5호
• /
• pp.704-713
• /
• 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.