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Meta-Transcriptomic Analysis Reveals the Virome and Viral Genomic Evolution of Medically Important Mites.

Mites are notorious for being vectors transmitting infectious pathogens and source of allergens causing allergic conditions in animals and h … A virome identified here provides not only significant insights into the diversity and evolution of RNA viruses in mites, but also a solid knowledge base for studying their roles in human diseases.IMPORTANCE Mites are important group of arthropods that are associated with a variety of human diseases including scrub typhus and asthma. However, it remains uncle …

Applicability of polyethylene glycol precipitation followed by acid guanidinium thiocyanate-phenol-chloroform extraction for the detection of SARS-CoV-2 RNA from municipal wastewater.

The primary concentration and molecular process are critical to implement wastewater-based epidemiology for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the previously developed methods were optimized for nonenveloped viruses. Few studies evaluated if the methods are applicable to the efficient recovery of enveloped viruses from various types of raw sewage. This study aims (1) to compare the whole process recovery of Pseudomonas phage φ6, a surrogate for enveloped viruses, among combinations of primary concentration [ultrafiltration (UF), electronegative membrane vort

Enhanced broad spectrum in vitro antiviral efficacy of 3-F-4-MeO-Bn, 3-CN, and 4-CN derivatives of lipid remdesivir nucleoside monophosphate prodrugs.

Broad spectrum oral antivirals are urgently needed for the early treatment of many RNA viruses of clinical concern. We previously described the synthesis of 1-O-octadecyl-2-O-benzyl-glycero-3-phospho-RVn (V2043), an orally bioavailable lipid prodrug of remdesivir nucleoside (RVn, GS-441524) with broad spectrum antiviral activity against viruses with pandemic potential. Here we compared the relative activity of V2043 with new RVn lipid prodrugs containing sn-1 alkyl ether or sn-2 glycerol modifications. We found that 3-F-4-MeO-Bn, 3-CN-Bn, and 4-CN-Bn sn-2 glycerol modifications improved antivi…

COVID-19: Prospective Challenges and Potential Vaccines.

CONTEXT: RNA viruses exhibit an extraordinary ability to evolve in a changing environment and to switch from animal hosts to humans. The ongoing COVID-19 pandemic, recognized as a respiratory disease, is an example of zoonotic transmission of the RNA virus known as SARS-CoV-2. The development and regulatory approval of a vaccine against SARS-CoV-2 pose multiple preventive and therapeutic challenges, especially during an ongoing pandemic. OBJECTIVE: The review intended to examine the challenges and recent achievements in the development of vaccine candidates against COVID-19. DESIGN: The rese…

Tiny Regulators in Viral Infection: Carving SARS-CoV-2 by miRNAs.

Viruses are microscopic biological entities that can cause diseases. Viruses require a host cell to replicate and generate progeny. Once inside, viruses hijack the main cellular machinery for their benefit, disrupting cell functions and causing detrimental effects on cell physiology. MicroRNAs are short, non-coding RNAs that regulate gene expression. Recent works have shown that cell-miRNAs can modulate antiviral defense during viral infection, and viruses can disrupt these existing miRNA networks. Furthermore, multiple RNA viruses encode their own miRNAs to evade the host immune response. In …

High throughput sequencing sheds light on the viral diversity in Aedes aegypti mosquitoes from Binh Thuan Province, Vietnam.

Mosquitoes are important vectors for various infectious pathogens. More than 200 species of mosquitoes are common in Vietnam, one of the mai … ridae; Phenuiviridae; and Orthomyxoviridae. The other seven species belonged to recently identified RNA viruses whose taxonomic position is undefined in the current classification of the International Committee on Taxonomy of Viruses (ICTV). This is the first study to reveal the diversity of RNA viruses associated with Aedes aegypti mosquitoes in Vietnam, whi …

The inhibition mechanism of Wolbachia on mosquito-borne RNA virus replication as seen through lipid metabolism regulation.

Mosquito-borne RNA viruses, including but not limited to the dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV), pose serious threats to global public health. Current countermeasure approaches are frequently plagued by insufficient coverage, susceptibility to drug resistance, and poor sustainability. Wolbachia, a natural symbiont within mosquitoes, has been shown to block the replication and transmission of mosquito-borne RNA viruses. In recent years, increasing attention has focused on the mechanism of its antiviral action, which involves the regulation of host lipid metabo…

Nucleosides and emerging viruses: A new story.

With several US Food and Drug Administration (FDA)-approved drugs and high barriers to resistance, nucleoside and nucleotide analogs remain the cornerstone of antiviral therapies for not only herpesviruses, but also HIV and hepatitis viruses (B and C); however, with the exception of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which vaccines have been developed at unprecedented speed, there are no vaccines or small antivirals yet available for (re)emerging viruses, which are primarily RNA viruses. Thus, herein, we present an overview of ribonucleoside analogs recently deve…

Metavirome analysis of domestic sheep in Shaanxi, Gansu, and Ningxia, China.

Sheep play an important role in China's agricultural development, but they are also potential hosts for many viruses, some of which have been identified as zoonotic pathogens, which may pose a serious threat to social public health and animal husbandry. Therefore, clarifying the characteristics of viruses in sheep will provide an important basis for the study of pathogenic ecology and viral evolution of viruses carried by sheep. We collected nasal and anal swabs from 688 sheep in 22 counties in Shaanxi, Gansu, and Ningxia, China, between January 2022 and July 2023, and utilized next-generation

Viral cysteine proteinases.

Dozens of novel cysteine proteinases have been identified in positive single-stranded RNA viruses and, for the first time, in large double-stranded DNA viruses. The majority of these proteins are distantly related to papain or chymotrypsin and may be direct descendants of primordial proteolytic enzymes. Virus genome synthesis and expression, virion formation, virion entry into the host cell, as well as cellular architecture and functioning can be under the control of viral cysteine proteinases during infection. RNA virus proteinases mediate their liberation from giant multidomain precursors in…

An Extended Primer Grip of Picornavirus Polymerase Facilitates Sexual RNA Replication Mechanisms.

Picornaviruses have both asexual and sexual RNA replication mechanisms. Asexual RNA replication mechanisms involve one parental template, whereas sexual RNA replication mechanisms involve two or more parental templates. Because sexual RNA replication mechanisms counteract ribavirin-induced error catastrophe, we selected for ribavirin-resistant poliovirus to identify polymerase residues that facilitate sexual RNA replication mechanisms. We used serial passage in ribavirin, beginning with a variety of ribavirin-sensitive and ribavirin-resistant parental viruses. Ribavirin-sensitive virus contain

Moving On Out: Transport and Packaging of Influenza Viral RNA into Virions.

Influenza A viruses bear an eight-segmented single-stranded negative-sense RNA genome that is replicated in the nucleus. Newly synthesized viral RNA (vRNA) segments are exported from the nucleus and transported to the plasma membrane for packaging into progeny virions. Influenza viruses exploit many host proteins during these events, and this is the portion of the viral life cycle when genetic reassortment among influenza viruses occurs. Reassortment among influenza A viruses allows viruses to expand their host range, virulence, and pandemic potential. This review covers recent studies on the

RNA-dependent RNA polymerase activity related to the 20S RNA replicon of Saccharomyces cerevisiae.

Saccharomyces cerevisiae contains two double-stranded RNA (dsRNA) viruses (L-A and L-BC) and two different single-stranded (ssRNA) replicons (20S RNA and 23S RNA). Replicase (dsRNA synthesis on a ssRNA template) and transcriptase (ssRNA synthesis on a dsRNA template) activities have been described for L-A and L-BC viruses, but not for 20S or 23S RNA. We report the characterization of a new in vitro RNA replicase activity in S. cerevisiae. This activity is detected after partial purification of a particulate fraction in CsCl gradients where it migrates at the density of free protein. The activi

Genomic organization of GB viruses A and B: two new members of the Flaviviridae associated with GB agent hepatitis.

The genomes of two positive-strand RNA viruses have recently been cloned from the serum of a GB agent-infected tamarin by using representational difference analysis. The two agent, GB viruses A and B (GBV-A and GBV-B, respectively), have genomes of 9,493 and 9,143 nucleotides, respectively, and single large open reading frames that encode potential polyprotein precursors of 2,972 and 2,864 amino acids, respectively. The genomes of these agents are organized much like those of other pestiviruses and flaviviruses, with genes predicted to encode structural and nonstructural proteins located at th…

Co-Infection Patterns in Individual Ixodes scapularis Ticks Reveal Associations between Viral, Eukaryotic and Bacterial Microorganisms.

Ixodes scapularis ticks harbor a variety of microorganisms, including eukaryotes, bacteria and viruses. Some of these can be transmitted to and cause disease in humans and other vertebrates. Others are not pathogenic, but may impact the ability of the tick to harbor and transmit pathogens. A growing number of studies have examined the influence of bacteria on tick vector competence but the influence of the tick virome remains less clear, despite a surge in the discovery of tick-associated viruses. In this study, we performed shotgun RNA sequencing on 112 individual adult I. scapularis collecte

Viruses Associated with Acute Conjunctivitis in Vanuatu.

The first manifestation of a viral infection may be conjunctivitis. There are limited data on the etiology of viral conjunctivitis in Vanuatu, a country in the South Pacific Ocean. Patients presenting to one of two Vanuatu health centers with presumed infectious conjunctivitis were eligible if symptom onset was within 14 days of screening. Conjunctival and anterior nasal swabs were obtained and subjected to unbiased RNA deep sequencing (RNA-seq) to identify DNA and RNA viruses. For samples collected from May to November 2021, RNA-seq identified a viral etiology in 12/48 patients. Human adenovi…

The 5' ends of yeast killer factor RNAs are pppGp.

The 5' nucleotides of the double-stranded RNAs of yeast killer factor have been isolated by digestion with pancreatic, T1 and T2 RNase followed by two-dimensional electrophoresis. They were identified by bacterial alkaline phosphatase and snake venom phosphodiesterase digestions. Both the larger double-stranded RNA (L, of 2.5 x 10(6) daltons) and the smaller double-stranded RNA (M, of 1.4 x 10(6) daltons) have the 5' end groups pppGp. These 5' ends are dissimilar to those of the double-stranded RNAs of animal viruses but may be characteristic of the 5' ends of the double-stranded RNAs of funga

Вирусы РНК и ДНК вызывают аутоиммунные заболевания и/или деменции.

Существуют вирусные патогенные пути для возникновения аутоиммунных заболеваний, таких, как множественный склероз, прямо или косвенно, путем реактивации скрытых вирусов, включая герпесвирусы человека. После первоначальных инфекций эти вирусы ДНК могут вступать в латентность, но периодически возрождаться в активных инфекциях по следующим причинам: лечение, вызывающее иммунодепрессию; и инфекция иммунодепрессивными патогенами, включая вирусы РНК, стресс или недоедание. Непрямая причинно-следственная связь с аутоиммунными заболеваниями может использоваться для подавления иммунной системы вирусными

Совпадение в аннотации оригинала
There are viral pathogen pathways to initiate autoimmune diseases, such as multiple sclerosis, directly or indirectly, by reactivating laten … cal treatments inducing immunosuppressions; and infections by immunosuppressive pathogens including RNA viruses, stress or malnutrition. An indirect causation pathway for autoimmune diseases can utilize immune suppressions by RNA virus infections, which trigger reactivation of latent herpesviruses capable of directly causing autoimmune diseases. Although it i …

Mycoviruses and their role in fungal pathogenesis.

Nowadays, the focus of mycovirology research has expanded from plant pathogenic fungi and mycovirus mediated hypovirulence to include insect and human pathogenic fungi together with a range of mycovirus mediated phenotypes, such as hypervirulence, control of endophytic traits, regulation of metabolite production and drug resistance. In fungus-mycovirus-environmental interactions, the environment and both abiotic and biotic factors play crucial roles in whether and how mycovirus mediated phenotypes are manifest. Mycovirus infections result in alterations in the host transcriptome profile, via p

Structural landscape of the complete genomes of dengue virus serotypes and other viral hemorrhagic fevers.

BACKGROUND: With more than 300 million potentially infected people every year, and with the expanded habitat of mosquitoes due to climate change, Dengue virus (DENV) cannot be considered anymore only a tropical disease. The RNA secondary structure is a functional characteristic of RNA viruses, and together with the accumulated high-throughput sequencing data could provide general insights towards understanding virus biology. Here, we profiled the RNA secondary structure of > 7000 complete viral genomes from 11 different species focusing on viral hemorrhagic fevers, including DENV serotypes, EB…