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Proceedings of the National Academy of... Jan 2020Emerging and reemerging viruses are responsible for a number of recent epidemic outbreaks. A crucial step in predicting and controlling outbreaks is the timely and...
Emerging and reemerging viruses are responsible for a number of recent epidemic outbreaks. A crucial step in predicting and controlling outbreaks is the timely and accurate characterization of emerging virus strains. We present a portable microfluidic platform containing carbon nanotube arrays with differential filtration porosity for the rapid enrichment and optical identification of viruses. Different emerging strains (or unknown viruses) can be enriched and identified in real time through a multivirus capture component in conjunction with surface-enhanced Raman spectroscopy. More importantly, after viral capture and detection on a chip, viruses remain viable and get purified in a microdevice that permits subsequent in-depth characterizations by various conventional methods. We validated this platform using different subtypes of avian influenza A viruses and human samples with respiratory infections. This technology successfully enriched rhinovirus, influenza virus, and parainfluenza viruses, and maintained the stoichiometric viral proportions when the samples contained more than one type of virus, thus emulating coinfection. Viral capture and detection took only a few minutes with a 70-fold enrichment enhancement; detection could be achieved with as little as 10 EID/mL (50% egg infective dose per microliter), with a virus specificity of 90%. After enrichment using the device, we demonstrated by sequencing that the abundance of viral-specific reads significantly increased from 4.1 to 31.8% for parainfluenza and from 0.08 to 0.44% for influenza virus. This enrichment method coupled to Raman virus identification constitutes an innovative system that could be used to quickly track and monitor viral outbreaks in real time.
Topics: Humans; Influenza A virus; Microbiological Techniques; Microtechnology; Nanotubes, Carbon; Respiratory Tract Infections; Respirovirus; Rhinovirus; Sensitivity and Specificity; Silicon Dioxide; Spectrum Analysis, Raman; Staining and Labeling; Virion; Virology; Virus Diseases; Viruses
PubMed: 31882450
DOI: 10.1073/pnas.1910113117 -
Viruses Jun 2016Influenza A viruses (IAV) cause annual seasonal human respiratory disease epidemics. In addition, IAV have been implicated in occasional pandemics with inordinate health... (Review)
Review
Influenza A viruses (IAV) cause annual seasonal human respiratory disease epidemics. In addition, IAV have been implicated in occasional pandemics with inordinate health and economic consequences. Studying IAV, in vitro or in vivo, requires the use of laborious secondary methodologies to identify virus-infected cells. To circumvent this requirement, replication-competent IAV expressing an easily traceable reporter protein can be used. Here we discuss the development and applications of recombinant replication-competent IAV harboring diverse fluorescent or bioluminescent reporter genes in different locations of the viral genome. These viruses have been employed for in vitro and in vivo studies, such as the screening of neutralizing antibodies or antiviral compounds, the identification of host factors involved in viral replication, cell tropism, the development of vaccines, or the assessment of viral infection dynamics. In summary, reporter-expressing, replicating-competent IAV represent a powerful tool for the study of IAV both in vitro and in vivo.
Topics: Gene Expression; Genes, Reporter; Humans; Influenza A virus; Luminescent Proteins; Recombination, Genetic; Reverse Genetics; Staining and Labeling; Virology; Virus Replication
PubMed: 27347991
DOI: 10.3390/v8070179 -
Viruses Aug 2016The genome of influenza A viruses (IAV) consists of eight single-stranded negative sense viral RNAs (vRNAs) encapsidated into viral ribonucleoproteins (vRNPs). It is now... (Review)
Review
The genome of influenza A viruses (IAV) consists of eight single-stranded negative sense viral RNAs (vRNAs) encapsidated into viral ribonucleoproteins (vRNPs). It is now well established that genome packaging (i.e., the incorporation of a set of eight distinct vRNPs into budding viral particles), follows a specific pathway guided by segment-specific cis-acting packaging signals on each vRNA. However, the precise nature and function of the packaging signals, and the mechanisms underlying the assembly of vRNPs into sub-bundles in the cytoplasm and their selective packaging at the viral budding site, remain largely unknown. Here, we review the diverse and complementary methods currently being used to elucidate these aspects of the viral cycle. They range from conventional and competitive reverse genetics, single molecule imaging of vRNPs by fluorescence in situ hybridization (FISH) and high-resolution electron microscopy and tomography of budding viral particles, to solely in vitro approaches to investigate vRNA-vRNA interactions at the molecular level.
Topics: Electron Microscope Tomography; Humans; In Situ Hybridization, Fluorescence; Influenza A virus; Microscopy, Electron, Transmission; Reverse Genetics; Single Molecule Imaging; Virology; Virus Assembly
PubMed: 27517951
DOI: 10.3390/v8080218 -
Virologica Sinica Feb 2015There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By... (Review)
Review
There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well (Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specific disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay (Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes-from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.
Topics: Bacteriophages; History, 20th Century; History, 21st Century; Viral Proteins; Virology
PubMed: 25662888
DOI: 10.1007/s12250-014-3549-0 -
Journal of Virology Oct 2018The rise of populist movements worldwide is challenging science and motivating scientists to join the debate and enter politics. Based on my experience, taking a public... (Review)
Review
The rise of populist movements worldwide is challenging science and motivating scientists to join the debate and enter politics. Based on my experience, taking a public stand will not come without slanderous personal and institutional attacks as an attempt to shake scientific credibility. The virology community is at risk of similar misrepresentation; reflection on this topic, particularly on how to address such challenges, should be a priority, given we are in the "post-truth" era.
Topics: Biomedical Research; Politics; Trust; Virology
PubMed: 30089689
DOI: 10.1128/JVI.00757-18 -
Medecine Sciences : M/S Dec 2022Virology was born at the end of the 19 century from the recognition of so-called filterable infectious agents that passed through filters designed to retain bacteria....
Virology was born at the end of the 19 century from the recognition of so-called filterable infectious agents that passed through filters designed to retain bacteria. The study of these agents, in particular the tobacco mosaic virus and bacteriophages, has shown the originality of their structural and physico-chemical properties while stimulating the development of molecular biology. Animal viruses, in addition to their own characterization, have served as probes to explore the molecular functioning of eukaryotic cells, including genome organization, transcriptional regulation and mechanisms of oncogenesis. In the early 1960s, a precise definition of virions and mode of virus replication as well as an internationally recognized classification based on the molecular properties of these agents were published. Understanding the pathophysiology of viral infections over the past decades has led to the identification of many new viruses and the development of standardized procedures for virological diagnosis, specific antiviral chemotherapy and effective vaccinations. Combined with the success of more basic studies, these advances have contributed to the exceptionally positive record of virology over the past hundred year.
Topics: Animals; History, 20th Century; Tobacco Mosaic Virus; Viruses; Bacteriophages; Molecular Biology; Bacteria; Virology
PubMed: 36692273
DOI: 10.1051/medsci/2022162 -
Journal of Virology Feb 2023Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the...
Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the last 60+ years has responded to reduce this disease burden with vaccines and antivirals. Despite this long history, the COVID-19 pandemic has brought unprecedented attention to the field of virology. Some of this attention is focused on concern about the safe conduct of research with human pathogens. A small but vocal group of individuals has seized upon these concerns - conflating legitimate questions about safely conducting virus-related research with uncertainties over the origins of SARS-CoV-2. The result has fueled public confusion and, in many instances, ill-informed condemnation of virology. With this article, we seek to promote a return to rational discourse. We explain the use of gain-of-function approaches in science, discuss the possible origins of SARS-CoV-2 and outline current regulatory structures that provide oversight for virological research in the United States. By offering our expertise, we - a broad group of working virologists - seek to aid policy makers in navigating these controversial issues. Balanced, evidence-based discourse is essential to addressing public concern while maintaining and expanding much-needed research in virology.
Topics: Humans; COVID-19; Information Dissemination; Pandemics; Policy Making; Research; SARS-CoV-2; Virology; Virus Diseases; Viruses
PubMed: 36700640
DOI: 10.1128/jvi.00089-23 -
Proceedings of the National Academy of... Mar 2017
Topics: Germany; History, 20th Century; History, 21st Century; Neoplasms; Slovakia; Virology
PubMed: 28289211
DOI: 10.1073/pnas.1702501114 -
Viruses Aug 2019The last decade has been marked by two eminent discoveries that have changed our perception of the virology field: The discovery of giant viruses and a distinct new... (Review)
Review
The last decade has been marked by two eminent discoveries that have changed our perception of the virology field: The discovery of giant viruses and a distinct new class of viral agents that parasitize their viral factories, the virophages. Coculture and metagenomics have actively contributed to the expansion of the virophage family by isolating dozens of new members. This increase in the body of data on virophage not only revealed the diversity of the virophage group, but also the relevant ecological impact of these small viruses and their potential role in the dynamics of the microbial network. In addition, the isolation of virophages has led us to discover previously unknown features displayed by their host viruses and cells. In this review, we present an update of all the knowledge on the isolation, biology, genomics, and morphological features of the virophages, a decade after the discovery of their first member, the Sputnik virophage. We discuss their parasitic lifestyle as viruses of the giant virus factories, genetic parasites of their genomes, and then their role as a key component or target for some host defense mechanisms during the tripartite virophage-giant virus-host cell interaction. We also present the latest advances regarding their origin, classification, and definition that have been widely discussed.
Topics: Animals; Biological Evolution; Genome, Viral; Genomics; Giant Viruses; History, 21st Century; Host-Pathogen Interactions; Humans; Interspersed Repetitive Sequences; Life Cycle Stages; Metagenomics; Research; Virology; Virophages
PubMed: 31398856
DOI: 10.3390/v11080733 -
Journal of Microbiology, Immunology,... Apr 2015Minigenomes (MGs) are complementary DNAs of the synthetic analogs of genomic RNA. MGs are widely used to study the life cycle of the Paramyxoviridae family of viruses.... (Review)
Review
Minigenomes (MGs) are complementary DNAs of the synthetic analogs of genomic RNA. MGs are widely used to study the life cycle of the Paramyxoviridae family of viruses. MG-based studies have provided valuable insights into the mechanisms of viral replication and transcription in this family, including the roles of viral proteins, the location and boundaries of the cis-acting elements, the functional domains of trans-acting proteins, techniques for the measurement of neutralizing antibody, virus-host interactions, and the structure and function of viral RNA. This article provides a brief overview of the principle and application of MG technology in studies involving members of the Paramyxoviridae family. The advantages, potential limitations, and future scope of MG technology are also discussed.
Topics: Genome, Viral; Host-Pathogen Interactions; Molecular Biology; Paramyxoviridae; Virology; Virus Physiological Phenomena
PubMed: 24767419
DOI: 10.1016/j.jmii.2014.02.008