Numerous host factors function as intrinsic antiviral effectors to attenuate viral replication. MARCH8 is an E3 ubiquitin ligase that has been identified as a host restriction factor that inhibits the replication of various viruses. This study elucidated the mechanism by which MARCH8 restricts respiratory syncytial virus (RSV) replication through selective degradation of the viral small hydrophobic (SH) protein.
View Article and Find Full Text PDFBackground: Amino acid (AA) substitutions in the fusion protein of respiratory syncytial virus (RSV) and their effects remain unclear. We aimed to analyze AA substitutions in main neutralizing epitopes of the fusion (F) protein.
Methods: We analyzed F protein genes of 236 RSV strains isolated from children hospitalized with RSV infection in Fukushima, Japan (June 2008-February 2023).
Unlabelled: A critical aspect of the mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the protease-mediated activation of the viral spike (S) protein. The type II transmembrane serine protease TMPRSS2 is crucial for SARS-CoV-2 infection in lung epithelial Calu-3 cells and murine airways. However, the importance of TMPRSS2 needs to be re-examined because the ability to utilize TMPRSS2 is significantly reduced in the Omicron variants that spread globally.
View Article and Find Full Text PDFUnlabelled: Human parainfluenza virus (HPIV) causes respiratory infections, which are exacerbated in children and older people. Correct evaluation of viral characteristics is essential for the study of countermeasures. However, adaptation of viruses to cultured cells during isolation or propagation might select laboratory passage-associated mutations that modify the characteristics of the virus.
View Article and Find Full Text PDFHuman metapneumovirus (hMPV) is genetically classified into two major subgroups, A and B, based on attachment glycoprotein (G protein) gene sequences. The A2 subgroup is further separated into three subdivisions, A2a, A2b (A2b1), and A2c (A2b2). Subgroup A2c viruses carrying 180- or 111-nucleotide duplications in the G gene (A2c or A2c ) have been reported in Japan and Spain.
View Article and Find Full Text PDFHuman metapneumovirus (hMPV) is a common cause of respiratory infections in children. Many genetic diagnostic assays have been developed, but most detect hMPV regardless of the subgroup. In this study, we developed a real-time RT-PCR assay that can detect and identify the two major subgroups of hMPV (A and B) in one tube.
View Article and Find Full Text PDFHuman respiratory syncytial viruses (HRSVs) are divided into subgroups A and B, which are further divided based on the nucleotide sequence of the second hypervariable region (HVR) of the attachment glycoprotein (G) gene. Understanding the molecular diversity of HRSV before and during the coronavirus disease 2019 (COVID-19) pandemic can provide insights into the effects of the pandemic on HRSV dissemination and guide vaccine development. Here, we analyzed HRSVs isolated in Fukushima Prefecture from September 2017 to December 2021.
View Article and Find Full Text PDFObjectives: To establish a point-of-care test for coronavirus disease 2019 (COVID-19), we developed a dry loop-mediated isothermal amplification (LAMP) method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA.
Methods: We carried out reverse transcription (RT)-LAMP using the Loopamp SARS-CoV-2 Detection kit (Eiken Chemical, Tokyo, Japan). The entire mixture, except for the primers, is dried and immobilized inside the tube lid.
Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus that causes MERS, which is endemic in the Middle East. The absence of human cases in Africa despite the presence of MERS-CoV suggests virological differences between MERS-CoVs in Africa and the Middle East. In fact, in the laboratory, recombinant MERS-CoV carrying the spike (S) protein of Ethiopian isolates exhibits attenuated properties, being more easily neutralized and replicating slower than viruses carrying the S protein of Middle Eastern isolate, EMC.
View Article and Find Full Text PDFThe Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2021 and gradually overtook the Delta variant, which was the predominant variant at that time. The Omicron variant has been consecutively replaced by related sublineages. The real-time RT-PCR assays developed by the National Institute of Infectious Diseases (NIID), Japan (i.
View Article and Find Full Text PDFThe World Health Organization initiated a global surveillance system for respiratory syncytial virus (RSV) in 2015, and the pilot surveillance is ongoing. The real-time RT-PCR RSV assays (Pan-RSV and duplex assays) developed by the United States Centers for Disease Control and Prevention are applied as the standard assays. To introduce these as standard assays in Japan, their practicality was evaluated using 2261 specimens obtained from pediatric inpatients in Japan, which were collected from 2018 to 2021.
View Article and Find Full Text PDFWe reported nearly complete genomic sequences of 12 serotypes of human rhinoviruses (HRVs) isolated from pediatric inpatients in Fukushima, Japan using an air-liquid interface culture of human bronchial tracheal epithelial cells. We found that various serotypes of HRV circulated locally and simultaneously from 2018 to 2021.
View Article and Find Full Text PDFThe impact of strengthening preventive measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the prevalence of respiratory viruses in children was examined. After the SARS-CoV-2 pandemic, the rate of multiple virus detection among hospitalized children decreased. Immediately after the SARS-CoV-2 pandemic, respiratory syncytial and parainfluenza viruses were rarely detected and subsequently reemerged.
View Article and Find Full Text PDFVirus isolates are not only useful for diagnosing infections, e.g., respiratory syncytial virus (RSV), but can also facilitate many aspects of practical viral studies such as analyses of antigenicity and the action mechanisms of antivirals, among others.
View Article and Find Full Text PDFIn the ongoing coronavirus diseases 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), real-time RT-PCR based diagnostic assays have been used for the detection of infection, but the positive signal of real-time RT-PCR does not necessarily indicate the infectivity of the patient. Due to the unique replication system of the coronavirus, primer/probe sets targeted nucleocapsid (N) and spike (S) protein detect the abundantly synthesized subgenomic RNAs as well as the virus genome, possibly making the assay unsuitable for estimation of the infectivity of the specimen, although it has an advantage for the diagnostic tests. In this study, the primer/probe set targeting the open reading frame 1a (ORF1a) gene was developed to specifically detect viral genomic RNA.
View Article and Find Full Text PDFIntroduction: Seasonal human coronavirus (HCoV)-229E, -NL63, -OC43, and -HKU1 are seasonal coronaviruses that cause colds in humans. However, the clinical characteristics of pediatric inpatients infected with HCoVs are unclear. This study aimed to compare and clarify the epidemiological and clinical features of HCoVs and respiratory syncytial virus (RSV), which commonly causes severe respiratory infections in children.
View Article and Find Full Text PDFWe report 13 genomic sequences of human bocavirus 1 isolated from pediatric inpatients in Fukushima, Japan, using an air-liquid interface culture of human bronchial tracheal epithelial cells. This work suggests the endemic circulation of a human bocavirus variant with a unique amino acid signature in Fukushima.
View Article and Find Full Text PDFVarious variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began emerging worldwide from the end of 2020 to the beginning of 2021. The variants GRY/VOC202012/01 (B1.1.
View Article and Find Full Text PDFSoon after the 2019 outbreak of coronavirus disease 2019 in Wuhan, China, a protocol for real-time RT-PCR assay detection of severe acute respiratory syndrome coronavirus (SARS-CoV-2) was established by the National Institute of Infectious Diseases (NIID) in Japan. The protocol used Charité's nucleocapsid (Sarbeco-N) and NIID nucleocapsid (NIID-N2) assays. During the following months, SARS-CoV-2 spread and caused a global pandemic, and various SARS-CoV-2 sequences were registered in public databases, such as the Global Initiative on Sharing All Influenza Data (GISAID).
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