Результаты поиска

Two novel simian arteriviruses in captive and wild baboons (Papio spp.).

UNLABELLED: Since the 1960s, simian hemorrhagic fever virus (SHFV; Nidovirales, Arteriviridae) has caused highly fatal outbreaks of viral hemorrhagic fever in captive Asian macaque colonies. However, the source(s) of these outbreaks and the natural reservoir(s) of this virus remain obscure. Here we report the identification of two novel, highly divergent simian arteriviruses related to SHFV, Mikumi yellow baboon virus 1 (MYBV-1) and Southwest baboon virus 1 (SWBV-1), in wild and captive baboons, respectively, and demonstrate the recent transmission of SWBV-1 among captive baboons. These findin…

Structure-based virtual screening of phytochemicals and repurposing of FDA approved antiviral drugs unravels lead molecules as potential inhibitors of coronavirus 3C-like protease enzyme.

Coronaviruses are enveloped positive-strand RNA viruses belonging to family Coronaviridae and order Nidovirales which cause infections in birds and mammals. Among the human coronaviruses, highly pathogenic ones are Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome coronavirus (MERS-CoV) which have been implicated in severe respiratory syndrome in humans. There are no approved antiviral drugs or vaccines for the treatment of human CoV infection to date. The recent outbreak of new coronavirus pandemic, coronavirus disease 2019 (COVID-19) has caused…

Porcine Hemagglutinating Encephalomyelitis Virus: A Review.

The porcine hemagglutinating encephalomyelitis virus (PHEV) is classified as a member of genus Betacoronavirus, family Coronaviridae, sub-family Cornavirinae, and order Nidovirales. PHEV shares the same genomic organization, replication strategy, and expression of viral proteins as other nidoviruses. PHEV produces vomiting and wasting disease (VWD) and/or encephalomyelitis, being the only known neurotropic coronavirus affecting pigs. First clinical outbreak was reported in 1957 in Ontario, Canada. Although pigs are the only species susceptible to natural PHEV infections, the virus displays neu…

Alpha- and Beta-Coronaviruses in Humans and Animals: Taxonomy, Reservoirs, Hosts, and Interspecies Transmission.

The Coronaviridae family represents a broad group of RNA-containing viruses that infect humans and animals. This family belongs to the order Nidovirales and is divided into four main genera: α-CoV, β-CoV, γ-CoV and δ-CoV. It is particularly noteworthy that representatives of β-CoV have caused serious epidemics in humans, such as the outbreaks of SARS-CoV, MERS-CoV, and COVID-19 caused by SARS-CoV-2. Although the clinical manifestations of CoVs can range from mild cold-like symptoms to severe respiratory diseases, they share common features in their structure, modes of transmission, and natural…

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2): An Update.

Coronaviruses (CoVs) belong to the family of Coronaviridae, the order Nidovirales, and the genus Coronavirus. They are the largest group of viruses causing respiratory and gastrointestinal infections. Morphologically, CoVs are enveloped viruses containing a non-segmented positive-sense, single-stranded ribonucleic acid (RNA) viruses. CoVs are categorized into four important genera that include Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. A novel member of human CoV that has recently emerged in Wuhan, China, is now formally named as SARS-CoV-2 (severe acute respira…

An intra-family conserved high-order RNA structure within the M ORF is important for arterivirus subgenomic RNA accumulation and infectious virus production.

Synthesis of subgenomic RNAs is a strategy commonly used by polycistronic positive-sense single-stranded RNA viruses to express 3'-proximal genes. Members of the order Nidovirales, including coronaviruses and arteriviruses, use a unique discontinuous transcription strategy to synthesize subgenomic RNAs. In this study, in silico synonymous site conservation analysis and RNA structure folding predicted the existence of intra-family conserved high-order RNA structure within the M ORF of arteriviral genomes, which was further confirmed by RNA secondary structure probing. This RNA structure was det…

The Curious Case of the Nidovirus Exoribonuclease: Its Role in RNA Synthesis and Replication Fidelity.

Among RNA viruses, the order Nidovirales stands out for including viruses with the largest RNA genomes currently known. Nidoviruses employ a complex RNA-synthesizing machinery comprising a variety of non-structural proteins (nsps). One of the postulated drivers of the expansion of nidovirus genomes is the presence of a proofreading 3'-to-5' exoribonuclease (ExoN) belonging to the DEDDh family. ExoN may enhance the fidelity of RNA synthesis by correcting nucleotide incorporation errors made by the RNA-dependent RNA polymerase. Here, we review our current understanding of ExoN evolution, structu…

Characterization of Self-Processing Activities and Substrate Specificities of Porcine Torovirus 3C-Like Protease.

The 3C-like protease (3CLpro) of nidovirus plays an important role in viral replication and manipulation of host antiviral innate immunity, which makes it an ideal antiviral target. Here, we characterized that porcine torovirus (PToV; family Tobaniviridae, order Nidovirales) 3CLpro autocatalytically releases itself from the viral precursor protein by self-cleavage. Site-directed mutagenesis suggested that PToV 3CLpro, as a serine protease, employed His53 and Ser160 as the active-site residues. Interestingly, unlike most nidovirus 3CLpro, the P1 residue plays a less essential role in N-terminal…

Abundant and Diverse RNA Viruses in Insects Revealed by RNA-Seq Analysis: Ecological and Evolutionary Implications.

Increasing data indicate that insects serve as major reservoirs and vectors of viruses, which account for the continuously increasing ecolog … known insect-associated viruses within Flaviviridae, Picornavirales, Bunyavirales, Mononegavirales, Nidovirales, Reoviridae, and Negevirus More appeared to form novel clusters within previously described taxa or could be resolved as paraphyletic, including the first astrovirus identified in insects, in which many were sufficiently divergent to warrant the est …

Murine Hepatitis Virus nsp14 Exoribonuclease Activity Is Required for Resistance to Innate Immunity.

Coronaviruses (CoVs) are positive-sense RNA viruses that infect numerous mammalian and avian species and are capable of causing severe and lethal disease in humans. CoVs encode several innate immune antagonists that counteract the host innate immune response to facilitate efficient viral replication. CoV nonstructural protein 14 (nsp14) encodes 3'-to-5' exoribonuclease activity (ExoN), which performs a proofreading function and is required for high-fidelity replication. Outside of the order Nidovirales, arenaviruses are the only RNA viruses that encode an ExoN, which functions to degrade doubl…

Conserved structural features of RNA export pores spanning the double membrane of arterivirus and coronavirus replication organelles.

UNLABELLED: Coronaviruses and arteriviruses are distantly related positive-stranded RNA virus families within the order Nidovirales. Both transform intracellular membranes into double-membrane vesicles (DMVs) that serve as replication organelles. Newly made viral RNA presumably exits DMVs through double-membrane-spanning molecular pores formed by coronavirus nsp3-nsp4 and arterivirus nsp2-nsp3. Although sub-nanometer resolution structural information is available for the coronavirus DMV pore, only low-resolution data exist for the pore of the prototypic arterivirus equine arteritis virus (EAV)…

Lineage A Betacoronavirus NS2 Proteins and the Homologous Torovirus Berne pp1a Carboxy-Terminal Domain Are Phosphodiesterases That Antagonize Activation of RNase L.

Viruses in the family Coronaviridae, within the order Nidovirales, are etiologic agents of a range of human and animal diseases, including both mild and severe respiratory diseases in humans. These viruses encode conserved replicase and structural proteins as well as more diverse accessory proteins, encoded in the 3' ends of their genomes, that often act as host cell antagonists. We previously showed that 2',5'-phosphodiesterases (2',5'-PDEs) encoded by the prototypical Betacoronavirus, mouse hepatitis virus (MHV), and by Middle East respiratory syndrome-associated coronavirus antagonize the o…

Current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (PRRS) virus: comparison of the North American and European isolates.

Porcine reproductive and respiratory syndrome virus (PRRSV) belongs to the recently recognized Arteriviridae family within the genus Arterivirus, order Nidovirales, which also includes equine arteritis virus (EAV), lactate dehydrogenase-elevating virus (LDV), and simian hemorrhagic fever virus (SHFV). Mature viral particles are composed of an envelope 50-72 nm in diameter, with an isometric core about 20-30 nm enclosing a linear positive-stranded RNA genome of approximately 15 kb. The virions are assembled by the budding of preformed nucleocapsids into the lumen of the smooth endoplasmic retic…

Insights into COVID-19 Vaccine Development Based on Immunogenic Structural Proteins of SARS-CoV-2, Host Immune Responses, and Herd Immunity.

The first quarter of the 21st century has remarkably been characterized by a multitude of challenges confronting human society as a whole in … ollectively referred to as coronaviruses, and taxonomically placed under the realm Riboviria, order Nidovirales, suborder Cornidovirineae, family Coronaviridae, subfamily Orthocoronavirinae, genus Betacoronavirus, and subgenus Sarbecovirus. As of 23 September 2021, the ongoing SARS-CoV-2 pandemic has globally resulted in around 229 million and 4.7 million rep …

An efficacy and safety report based on randomized controlled single-blinded multi-centre clinical trial of ZingiVir-H, a novel herbo-mineral formulation designed as an add-on therapy in adult patients with mild to moderate COVID-19.

OBJECTIVE: Coronaviruses, hence named because of the crown-like spikes on the viral envelope, are members of Coronaviridae family and Order Nidovirales. SARS-CoV-2 is the seventh human pathogenic coronavirus identified after HCoV-229E, HCoV-OC43, SARS-CoV (SARS-CoV-1), HCoV-NL63, CoV-HKU1, and MERS-CoV. SARS-Cov-2 is highly similar to SARS-CoV. COVID-19 is the corresponding acute disease caused by SARS-CoV-2 that was initially reported in Wuhan, China towards the end of 2019 and spread to millions of humans globally. Unfortunately, limited studies were available on the efficacy of antiviral dr…

Ferret coronavirus-associated diseases.

A novel coronavirus of ferrets was first described in 1993. This coronavirus caused an enteric disease called epizootic catarrhal enteritis (ECE). Recently, a ferret systemic coronavirus (FRSCV)-associated disease was discovered. This new systemic disease resembles the dry form of feline infectious peritonitis (FIP) and has been reported in the United States and Europe. This article addresses the clinical signs, pathology, pathogenesis, diagnosis, treatment, and prevention of this ferret FIP-like disease.

Совпадение в полном тексте источника
… Coronaviruses are large, enveloped, positive-stranded RNA viruses classified under the genus Coronavirus within the family Coronaviridae, order Nidovirales. 1 Based on sequence homology, they are subdivided into three groups. 2 Group 1 coronaviruses include some important causes of enteric disease in …

Beyond Vaccines: Clinical Status of Prospective COVID-19 Therapeutics.

Since November 2019 the SARS-CoV-2 pandemic has caused nearly 200 million infection and more than 4 million deaths globally (Updated information from the World Health Organization, as on 2nd Aug 2021). Within only one year into the pandemic, several vaccines were designed and reached approval for the immunization of the world population. The remarkable protective effects of the manufactured vaccines are demonstrated in countries with high vaccination rates, such as Israel and UK. However, limited production capacities, poor distribution infrastructures and political hesitations still hamper th

Совпадение в полном тексте источника
… SARS-CoV2 Replication Cycle Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a positive-sense, single-stranded RNA virus that belongs to the lineage β-coronavirus-2b the family Coronaviridae and the order Nidovirales ( 1 ). …

Primed for global coronavirus pandemic: Emerging research and clinical outcome.

The global effort to combat and contain the coronavirus disease 2019 (COVID-19) caused by the recently discovered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is now proceeding on a war footing. The world was slow to react to the developing crisis, but once the contours of the impending calamity became evident, the different state and non-state actors have raced to put their act together. The COVID-19 pandemic has blatantly exposed the shortcomings of our healthcare system and the limitations of medical science, despite considerable advances in recent years. To effectively tack

Совпадение в полном тексте источника
… Coronaviruses (CoV) belong to the subfamily Orthocoronavirinae of the family Coronaviridae, order Nidovirales and realm Riboviria. These zoonotic viruses are composed of a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry enclosed in a lipid envelope. …

Potential drug development and therapeutic approaches for clinical intervention in COVID-19.

While the vaccination is now available to many countries and will slowly dissipate to others, effective therapeutics for COVID-19 is still illusive. The SARS-CoV-2 pandemic has posed an unprecedented challenge to researchers, scientists, and clinicians and affected the wellbeing of millions of people worldwide. Since the beginning of the pandemic, a multitude of existing anti-viral, antibiotic, antimalarial, and anticancer drugs have been tested, and some have shown potency in the treatment and management of COVID-19, albeit others failed to leave any positive impact and a few also became cont

Совпадение в полном тексте источника
… Classification International Committee on Taxonomy of Viruses (ICTV) in its tenth report, classified coronaviruses in order- Nidovirales, suborder- Cornidovirineae, family- Coronaviridae, and subfamily- Orthocoronavirinae. …

Role of phytoconstituents in the management of COVID-19.

BackgroundCOVID-19, a severe global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged as one of the most threatening transmissible disease. As a great threat to global public health, the development of treatment options has become vital, and a rush to find a cure has mobilized researchers globally from all areas.Scope and approachThis review focuses on deciphering the potential of different secondary metabolites from medicinal plants as therapeutic options either as inhibitors of therapeutic targets of SARS-CoV-2 or as blockers of viral particles entry

Совпадение в полном тексте источника
… available, only existing drugs are in use for symptoms Countries effected | 29 | 26 | >140 Fatality Rate | 9.5% | 34.4% | 2.3% Family of coronaviruses According to International Committee on Taxonomy of Viruses, coronaviruses come under subfamily of Coronavirinae from the family Coronaviridae and order Nidovirales …