Unknown Viruses Research Articles

Unveiling bat-borne viruses: a comprehensive classification and analysis of virome evolution

BackgroundBats (Order Chiroptera) are an important reservoir of emerging zoonotic microbes, including viruses of public health concern such as henipaviruses, lyssaviruses, and SARS-related coronaviruses. Despite the continued discovery of new viruses in bat populations, a significant proportion of these viral agents remain uncharacterized, highlighting the imperative for additional research aimed at elucidating their evolutionary relationship and taxonomic classification.ResultsIn order to delve deeper into the viral reservoir hosted by bats, the present study employed Next Generation Sequencing (NGS) technology to analyze 13,105 swab samples obtained from various locations in China. Analysis of 378 sample pools revealed the presence of 846 vertebrate-associated viruses. Subsequent thorough examination, adhering to the International Committee on Taxonomy of Viruses (ICTV) criteria for virus classification, identified a total of 120 putative viral species with the potential to emerge as novel viruses, comprising a total of 294 viral strains. Phylogenetic analysis of conserved genomic regions indicated the novel virus exhibited a diverse array of viral lineages and branches, some of which displayed close genetic relationships to known human and livestock pathogens, such as poxviruses and pestiviruses.ConclusionsThis study investigates the breadth of DNA and RNA viruses harbored by bats, delineating several novel evolutionary lineages and offering significant contributions to virus taxonomy. Furthermore, the identification of hitherto unknown viruses with relevance to human and livestock health underscores the importance of this study in encouraging infectious disease monitoring and management efforts in both public health and veterinary contexts.5R8JHumEnvkqKNe4tF9zBoVideo

Measuring influencing factors affecting mortality rates during the COVID-19 pandemic

ABSTRACT Background The COVID-19 pandemic has revealed clear deficiencies in global public health policies and healthcare systems when confronted with the emergence of a novel and deadly infectious disease. Objectives With 4 years elapsed since the onset of the pandemic, ample data now exist to analyse the associations between the implementation of diverse public health policies, sociodemographic factors and COVID-19 mortality rates. Methods This study utilised the dataset compiled by ‘Our World in Data’ spanning the period of the COVID-19 pandemic from 2020 to 2022. Stochastic frontier analysis was employed to assess the influencing factors and their relationship with mortality rates resulting from COVID-19 infections across 156 countries or regions. Results This study yielded several key findings: (1) There remains a 33% margin for improvement in the global mortality rate concerning the COVID-19 pandemic; (2) During the initial stage of the pandemic, when an effective vaccine was not yet available, implementing public health control policies could reduce both the infection and mortality rates; (3) Areas characterised by higher population densities, a greater proportion of individuals aged 65 and over, and elevated prevalence rates of diabetes demonstrated higher mortality rates; and (4) Increasing vaccination coverage emerged as an effective strategy for reducing mortality rates. Conclusions As our understanding of the COVID-19 virus improves, global economies and social interactions have gradually returned to normality. It is anticipated that the findings of this study can serve as a valuable reference in combating potential future pandemics caused by unknown viruses.

Detection of Double-Stranded RNA Intermediates During SARS-CoV-2 Infections of Syrian Golden Hamsters with Monoclonal Antibodies and Its Implications for Histopathological Evaluation of In Vivo Studies.

The SARS-CoV-2 pandemic has highlighted the challenges posed by the emergence and rapid global spread of previously unknown viruses. Early investigations on the pathogenesis of newly identified viruses are often hampered by a lack of appropriate sample material and conventional detection methods. In this study, viral replication within the lungs of SARS-CoV-2-infected Syrian golden hamsters was assessed by immunolabeling dsRNA intermediates with three different monoclonal antibodies in formalin-fixed, paraffin-embedded tissue samples. The presence of dsRNA was compared to viral antigen levels, viral titers, and genomic RNA replicates using three different variants of concern and an ancestral virus strain at a single time point and during the course of infection with an ancestral variant, and then validated using fluorescent 2-plex in situ hybridization. The results indicate that the detection of viral infection using anti-dsRNA antibodies is restricted to an early phase of infection with high viral replication activity. Additionally, the combined detection of dsRNA intermediates and viral antigens may help to bridge the interpretation gaps between viral antigen levels and viral titers at a single time point. Further testing in other viral infections or species is needed to assess the potential of dsRNA as an early marker for viral infections.

Revealing hidden viruses inducing similar yellowing symptoms or remaining asymptomatic in cucurbit crops

AbstractMixed viral infections occur frequently in plants, leading to diseases that can be difficult to diagnose, especially when an unknown virus is hidden behind expression of symptoms common to other viruses. We monitored aphid‐ and whitefly‐transmitted viruses in two cucurbit crops (melon and watermelon) for three consecutive seasons (2021–2023) across three production regions in Spain, focusing on the common yellowing and mosaic symptoms. A total of 984 symptomatic leaf samples from 246 field plots were tested for 10 frequently found cucurbit viruses. Cucurbit aphid‐borne yellows virus (CABYV) was the most prevalent virus infecting both cucurbit crops over the three seasons. Additionally, occurrence of watermelon mosaic virus (WMV) in samples with mosaic symptoms was significant. However, an important proportion of yellowing symptomatic samples tested negative for known viruses. Using a sequence‐independent approach, we identified a novel polerovirus, Pepo aphid‐borne yellows virus (PABYV), which was widespread, infecting both crops. Analysis of our long‐term cucurbit frozen‐sample collection revealed that PABYV had emerged in Spain in 2018, possibly unnoticed as its yellowing symptoms were similar to CABYV, with which it was frequently associated. Additionally, we found the cryptic Cucumis melo endornavirus (CmEV) in all tested melon samples from 2011 and, for the first time, in pumpkin. Genetic characterization of CABYV, PABYV and CmEV populations revealed a replacement of ancient CABYV isolates by contemporary ones, while PABYV and CmEV isolates were genetically homogenous among their populations. This study underlines the need for continuous surveillance and further investigation into common symptoms of mixed viral infections.

Metagenomic characterization of viruses in the serum of children with newly diagnosed cancer

Background and ObjectivesA large cohort of pediatric patients with various forms of childhood cancer was investigated for the presence of viruses using metagenomics. A total of 476 patient samples, collected between 1989 and 2018, were analyzed, representing various pediatric oncological diagnoses and a control group of non-malignant diagnoses. Study designThe study was carried out using metagenomic sequencing of serum samples. Viruses were identified and analyzed using bioinformatics methods, followed by Polymerase chain reaction (PCR) confirmation ResultsThe results indicate that a wide range of viruses can be detected in the bloodstream of children with newly diagnosed cancer. Nine viral genomes were identified: Human Pegivirus (HPgV), Hepatitis C virus, Parechovirus 1, Rhinovirus C, Human papillomavirus 116, Human polyomavirus 10, Parvovirus B19, and different variants of Torque Teno Virus (TTV). In this study, a previously unknown virus was found belonging to the Iflavirdae family in the order Picornavirales. HPGV was significantly more common in patients with leukemia compared to other conditions. ConclusionsThese results highlight the abundance of systemic virus infections in children, and the value of metagenomic sequencing for hypothesis forming regarding the associations between virus infections and cancer.

Diagnostics of viral infections using high-throughput genome sequencing data.

Plant viral infections cause significant economic losses, totalling $350 billion USD in 2021. With no treatment for virus-infected plants, accurate and efficient diagnosis is crucial to preventing and controlling these diseases. High-throughput sequencing (HTS) enables cost-efficient identification of known and unknown viruses. However, existing diagnostic pipelines face challenges. First, many methods depend on subjectively chosen parameter values, undermining their robustness across various data sources. Second, artifacts (e.g. false peaks) in the mapped sequence data can lead to incorrect diagnostic results. While some methods require manual or subjective verification to address these artifacts, others overlook them entirely, affecting the overall method performance and leading to imprecise or labour-intensive outcomes. To address these challenges, we introduce IIMI, a new automated analysis pipeline using machine learning to diagnose infections from 1583 plant viruses with HTS data. It adopts a data-driven approach for parameter selection, reducing subjectivity, and automatically filters out regions affected by artifacts, thus improving accuracy. Testing with in-house and published data shows IIMI's superiority over existing methods. Besides a prediction model, IIMI also provides resources on plant virus genomes, including annotations of regions prone to artifacts. The method is available as an R package (iimi) on CRAN and will integrate with the web application www.virtool.ca, enhancing accessibility and user convenience.

Preparing the developing world for the next pandemic: Evidence from China’s R&D blueprint for emerging infectious diseases

BackgroundWith double pressures of endemic and imported emerging infectious diseases (EIDs), China’s ability to detect, prevent and control the unknown virus is of regional and global interest. This study aimed to establish an R&D Blueprint for EIDs in China by identifying the list of prioritized diseases and medical countermeasures (MCMs) that need proactive actions for the next pandemic. MethodsThe process mainly referred to the World Health Organization’s prioritization methodology, supplemented by pipeline landscape, rapid risk assessment and multi-dimensional analysis. The study included five steps: 1) identifying potential pathogens, 2) screening into the long list, 3) prioritizing the long list, 4) identifying the final list and 5) generating an R&D Blueprint. ResultsChina’s R&D Blueprint identified 14 viral pathogens and two virus groups (i.e., Influenza HxNy and Coronavirus X) for proactive and representative MCM development. At least one diagnostic candidate in preclinical study, and one therapeutic and one vaccine candidate in Phase I/II clinical trials for each prioritized pathogen were suggested to be developed as strategic national stockpiles. Various generalized and innovative platform technologies were also highlighted for enhancing overall capacities of EID preparedness and response, covering basic research, experiment, detection, prevention and control, surveillance and information sharing. ConclusionsThis is the first study in developing countries that established an R&D Blueprint of prioritized diseases, countermeasures and technologies. Our findings could help to drive pre-emptive scientific and technological actions toward emerging pathogens that may cause the next epidemic and could provide evidence-based strategies for developing countries to establish their national health research agenda tailored to health and research context under resource-limited settings.

Viral diversity and co-evolutionary dynamics across the ant phylogeny.

Knowledge of viral biodiversity within insects, particularly within ants, is extremely limited with only a few environmental viruses from invasive ant species identified to date. This study documents and explores the viral communities in ants. We comprehensively profile the metagenomes of a phylogenetically broad group of 35 ant species with varied ecological traits and report the discovery of 3710 novel and unique ant-associated viral genomes. These previously unknown viruses discovered within this study constitute over 95% of all currently described ant viruses, significantly increasing our knowledge of the ant virosphere. The identified RNA and DNA viruses fill gaps in insect-associated viral phylogenies and uncover evolutionary histories characterized by both frequent host switching and co-divergence. Many ants also host diverse bacterial communities, and we discovered that approximately one-third of these new ant-associated viruses are bacteriophages. Two ecological categories, bacterial abundance in the host and habitat degradation are both correlated with ant viral diversity and help to structure viral communities within ants. These data demonstrate that the ant virosphere is remarkably diverse phylogenetically and genomically and provide a substantial foundation for studies in virus ecology and evolution within eukaryotes. We highlight the importance of studying insect-associated viruses in natural ecosystems in order to more thoroughly and effectively understand host-microbe evolutionary dynamics.

Targeted whole-genome recovery of single viral species in a complex environmental sample

Characterizing unknown viruses is essential for understanding viral ecology and preparing against viral outbreaks. Recovering complete genome sequences from environmental samples remains computationally challenging using metagenomics, especially for low-abundance species with uneven coverage. We present an experimental method for reliably recovering complete viral genomes from complex environmental samples. Individual genomes are encapsulated into droplets and amplified using multiple displacement amplification. A unique gene detection assay, which employs an RNA-based probe and an exonuclease, selectively identifies droplets containing the target viral genome. Labeled droplets are sorted using a microfluidic sorter, and genomes are extracted for sequencing. We demonstrate this method's efficacy by spiking two known viral genomes, Simian virus 40 (SV40, 5,243 bp) and Human Adenovirus 5 (HAd5, 35,938 bp), into a sewage sample with a final abundance in the droplets of around 0.1% and 0.015%, respectively. We achieve 100% recovery of the complete sequence of the spiked-in SV40 genome with uniform coverage distribution. For the larger HAd5 genome, we cover approximately 99.4% of its sequence. Notably, genome recovery is achieved with as few as one sorted droplet, which enables the recovery of any desired genomes in complex environmental samples, regardless of their abundance. This method enables single-genome whole-genome amplification and targeting characterizations of rare viral species and will facilitate our ability to access the mutational profile in single-virus genomes and contribute to an improved understanding of viral ecology.

A Comparative Assessment of the Pathogenic Potential of Newly Discovered Henipaviruses.

Recent advances in high-throughput sequencing technologies have led to the discovery of a plethora of previously unknown viruses in animal samples. Some of these newly detected viruses are closely related to human pathogens. A prime example are the henipaviruses. Both Nipah (NiV) and Hendra virus (HeV) cause severe disease in humans. Henipaviruses are of zoonotic origin, and animal hosts, including intermediate hosts, play a critical role in viral transmission to humans. The natural reservoir hosts of NiV and HeV seem to be restricted to a few fruit bat species of the Pteropus genus in distinct geographic areas. However, the recent discovery of novel henipa- and henipa-like viruses suggests that these viruses are far more widespread than was originally thought. To date, these new viruses have been found in a wide range of animal hosts, including bats, shrews, and rodents in Asia, Africa, Europe, and South America. Since these viruses are closely related to human pathogens, it is important to learn whether they pose a threat to human health. In this article, we summarize what is known about the newly discovered henipaviruses, highlight differences to NiV and HeV, and discuss their pathogenic potential.

Highly diverse RNA viruses and phage sequences concealed within birds.

The diversity of birds in most parts of the world is very high, and thus, they may carry different types of highly differentiated and unknown viruses. Thanks to advanced sequencing technologies, studies on the diversity of bird-associated viruses have increased over the past few years. In this study, a large-scale viral metagenomics survey was performed on cloacal swabs of 2,990 birds from nine provinces of the Chinese mainland. To detect undescribed RNA viruses in birds, more than 1,800 sequences sharing relatively low (<60%) amino acid sequence identity with the best match in the GenBank database were screened. Potentially novel viruses related to vertebrates have been identified, and several potential recombination signals were found. Additionally, hundreds of RNA viral sequences related to plants, fungi, and insects were detected, including previously unknown viruses. Furthermore, we investigated the novelty, functionality, and classification of the phages examined in this study. These viruses occupied topological positions on the evolutionary trees to a certain extent and might form novel putative families, genera, or species, thus providing information to fill the phylogenetic gaps of related viruses. These findings provided new insights into bird-associated viruses, but the interactions among these viruses remain unknown and require further investigation.IMPORTANCEStudying the diversity of RNA viruses in birds and mammals is crucial due to their potential impact on human health and the global ecosystem. Many RNA viruses, such as influenza and coronaviruses, have been shown to cross the species barrier and cause zoonotic diseases. In this metagenomics study involving 2,990 birds from at least 82 species, we identified over 1,800 RNA sequences with distant relationships to known viruses, some of which are rare in birds. The study highlights the scope and diversity of RNA viruses in birds, providing data to predict disease risks and monitor potential viral threats to wildlife, livestock, and human health. This information can aid in the development of strategies for disease prevention and control.

A Dual Strategy-In Vitro and In Silico-To Evaluate Human Antitetanus mAbs Addressing Their Potential Protective Action on TeNT Endocytosis in Primary Rat Neuronal Cells.

Tetanus disease, caused by C. tetani, starts with wounds or mucous layer contact. Prevented by vaccination, the lack of booster shots throughout life requires prophylactic treatment in case of accidents. The incidence of tetanus is high in underdeveloped countries, requiring the administration of antitetanus antibodies, usually derived from immunized horses or humans. Heterologous sera represent risks such as serum sickness. Human sera can carry unknown viruses. In the search for human monoclonal antibodies (mAbs) against TeNT (Tetanus Neurotoxin), we previously identified a panel of mAbs derived from B-cell sorting, selecting two nonrelated ones that binded to the C-terminal domain of TeNT (HCR/T), inhibiting its interaction with the cellular receptor ganglioside GT1b. Here, we present the results of cellular assays and molecular docking tools. TeNT internalization in neurons is prevented by more than 50% in neonatal rat spinal cord cells, determined by quantitative analysis of immunofluorescence punctate staining of Alexa Fluor 647 conjugated to TeNT. We also confirmed the mediator role of the Synaptic Vesicle Glycoprotein II (SV2) in TeNT endocytosis. The molecular docking assays to predict potential TeNT epitopes showed the binding of both antibodies to the HCR/T domain. A higher incidence was found between N1153 and W1297 when evaluating candidate residues for conformational epitope.

Risk factors for intensive care admission in pediatric patients with COVID-19 - results of the German na-tionwide inpatient sample

Abstract Funding Acknowledgements None. Background In December 2019 first patient-cases of pneumonia caused by an unknown virus were detected in Wuhan, China. From this day on, SARS-CoV-2 spread throughout the world with an enormous pace causing the deadliest pandemic of the twenty-first century. First infection cases in Germany were reported at the end of January 2020 in Bavaria and sustained transmission of SARS-CoV-2 resulted also in Germany in a strong spread of COVID-19 in the population. Although children and young people aged ≤18 years represent approximately 2%-5% of the SARS-CoV-2 cases globally, research efforts regarding COVID-19 pandemic have mainly focused on disease course of adults. Thus, early identification of children who must be monitored for life-threatening severe COVID-19 course remains difficult. Understanding of risk factors for ICU admission as one important bottleneck of adequate management regarding escalated treatment of COVID-19 pandemic is of outstanding interest to understand determinants, which are both crucial factors for adequate health care planning, decision making and pandemic management. Purpose We aimed to close this gap with identification of associated factors with pediatric ICU admissions in Germany. Methods We used the German nationwide inpatient sample analysing all hospitalised children ≤18 years with confirmed COVID-19 diagnosis in Germany between January 1st and December 31st, 2020 stratified fur ICU admission (source: RDC of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2020, own calculations). Results Overall, 3,360 cases of hospitalised children ≤18 years with COVID-19 infection were diagnosed in Germany 2020 (median age 7.0 [IQR 0.0-15.0] years, 49.8% of female sex); among them 4.3% had to be admitted on ICU. In-hospital death occurred in five patients with and three without ICU admission (3.5% vs. 0.1%, P&amp;lt;0.001) and ICU admission was independently associated with increased case-fatality (OR 21.573 [95%CI 4.191-111.044], P&amp;lt;0.001). Obesity (OR 3.419 [95%CI 1.300-8.993], P=0.013), diabetes mellitus (OR 6.929 [95%CI 3.327-14.432], P&amp;lt;0.001), pneumonia (OR 7.373 [95%CI 4.823-11.271], P&amp;lt;0.001), ARDS (OR 48.058 [95%CI 11.689-197.588], P&amp;lt;0.001) and multi-segmental Inflammatory syndrome caused by COVID-19 (OR 9.573 [95%CI 3.036-30.191], P&amp;lt;0.001), heart failure (OR 64.509 [95%CI 24.462-170.121], P&amp;lt;0.001), myocarditis (OR 4.682 [95%CI 1.278-17.149], P=0.020), acute and/or chronic kidney failure (OR 7.946 [95%CI 3.606-17.508], P&amp;lt;0.001), cancer (OR 5.220 [95%CI 2.599-10.485], P&amp;lt;0.001) and liver diseases (OR 5.501 [95%CI 2.177-13.899], P&amp;lt;0.001) were associated with ICU admission. Conclusions The proportion of hospitalized paediatric COVID-19 patients admitted on ICU in Germany was low with 4.3% accompanied by 3.5% case-fatality rate. Independent factors for ICU admission comprised cardio-vascular risk factors, comorbidities and complications of COVID-19.

A Host Receptor Nanodisc-Based Biosensor Platform for the Detection of a Specific Virus and Its Variants.

The host receptor is a key element in the initial stage of the virus entry into the host. The use of this host receptor is valuable as a sensing element for selectively and sensitively detecting specific viruses. Also, viruses tend to escape neutralizing antibodies through viral mutation but still utilize the cell entry process using the same host receptors, so it would be a powerful detection tool even for the mutant viruses. The angiotensin-converting enzyme 2 (ACE2) receptor, which is the representative host receptor, performs an essential function in facilitating viral penetration by interacting with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. In this study, we introduce a novel approach, where we fabricated a carbon nanotube field-effect transistor (CNT-FET) sensor and combined it with ACE2 receptor-embedded nanodisc (ND). ACE2 was produced using an E. coli expression system, purified, and integrated into the ND platform. ACE2 NDs showed robust functionality through interactions with a pseudotyped virus (PV) containing the spike protein, enabling sensitive detection of both SARS-CoV-2 and its genetic variations at 102 PFU/mL. The ACE ND-based sensor exhibited excellent selectivity by accurately differentiating SARS-CoV-2 wild-type and variants (Omicron, Delta) from other viruses (ZIKA and MERS-CoV). As a result of comparative analysis, ACE2 ND showed approximately 49% superior long-term functionality up to the second week compared to that of soluble ACE2. These findings highlight the high selectivity and sensitivity of host receptor-based sensors for detecting viral variants and provide a promising tool to prevent the spread of unknown viruses.

Prion meeting 2023: implications of a growing field

ABSTRACT The history of human prion diseases began with the original description, by Hans Gerhard Creutzfeldt and by Alfons Maria Jakob, of patients with a severe brain disease that included speech abnormalities, confusion, and myoclonus, in a disease that was then named Creutzfeldt Jakob disease (CJD). Later, in Papua New Guinea, a disease characterized by trembling was identified, and given the name “Kuru”. Neuropathological examination of the brains from CJD and Kuru patients, and of brains of sheep with scrapie disease revealed significant similarities and suggested a possible common mode of infection that, at the time, was thought to derive from an unknown virus that caused slow infections. John Stanley Griffith hypothesized that the agent causing these diseases was “probably a protein without nucleic acid” and, in 1982, Stanley Prusiner reported the identification of a proteinaceous infectious particle (coining the term prion) that was resistant to inactivation methods that were at the time standard for nucleic acids, and identified PrP as the major protein component of the infectious agent in scrapie and in Creutzfeldt-Jakob disease, classifying this also as a prion disease. Interestingly, the prion concept had been previously expanded to yeast proteins capable of replicating their conformation, seeding their own aggregation and transmitting phenotypic information. The prion concept has been more recently expanded to refer to misfolded proteins that are capable of converting a normal form of a protein into an abnormal form. The quest to understand and treat prion diseases has united a specific research community around the topic, and regular meetings (Prion Meetings) have taken place over the years to enable discussions, train junior researchers, and inspire research in the field.

Present Status of Viral Diseases of Grapevine (&lt;i&gt;Vitis Vinifera&lt;/i&gt; L.) and their Management Strategies in India

Grapevine is an important fruit crop cultivated in temperate, subtropical and tropical conditions in India. The maximum share in area, production, and productivity of grapes is governed by four states viz. Maharashtra, Karnataka, Tamil Nadu and Andhra Pradesh. The sudden and drastic changes in climatic conditions and the emergence of diseases have made grapevine cultivation more challenging. Fungal and bacterial diseases are the major constraints in the grapevine production. Besides, some viral diseases like Grapevine Leafroll Disease (GLD) and Rupestris Stem Pitting Associated Diseases (RSPD) are reported in Indian vineyards. Although the presence of Grapevine Leafroll-Associated Viruses (GLRaVs) viz., GLRaV-1, GLRaV-3, and GLRaV-4 are known the impact on yield and quality of the grapes is not yet studied. Similarly, the Rupestris Stem Pitting Associated Virus (RSPaV) is known to infect the Indian vineyards of different locations but a complete understanding of their overall impact on vineyards is lacking. Therefore, it is presumed that fewer or no losses occur due to GLD and RSPD diseases. There is a strong need for hours to study the impact of known viruses on physiological and yield contributing parameters. In addition to this, robust, rapid and reliable diagnostic techniques are required for the detection of known and unknown viruses. The presence of new and emerging viruses in the Indian vineyards cannot be overlooked. Further, for the management of the viruses and avoiding their spread, the availability of Disease-Free Quality Planting Material (DFQPM) is a prerequisite. To produce DFQPM, various tissue culture techniques need to be standardized for the elimination of the virus/es from the diseased vines. The Tissue Culture-Raised Quality Planting Material (TCQPM) needs to be further tested for genetic purity (true-to-type) and virus indexing to confirm DFQPM. By considering the importance of DFQPM, recently, the National Horticulture Board (NHB), Govt. of India in association with the Asian Development Bank (ADB) has initiated a National Mission on Clean Plant Programme. The implementation of this initiative is more challenging and expected to open different avenues of research and development in the production of DFQPM for the growers. This is an important and timely beginning of the production of DFQPM.

Structural Basis of HIV-1 gp41 N-trimer for Designing Bifunctional Peptide-based Fusion Inhibitors.

Pathogenic viruses that cause large-scale global or regional outbreaks almost always contain class I fusion proteins. Although the viruses differ in morphology, they all require fusion protein-mediated virus-host cell membranes during the early stages of host cell invasion. The CHR region and NHR region of fusion proteins can form the 6-HB structure to drive the fusion pore formation between viruses and host cells through metastable interactions. Here, we obtained bifunctional N-peptides with inhibitory activities against two viruses, HIV-1 and MERS-CoV, based on the sequences in the HIV-1 NHR region by constructing N-trimer conformation interacting with the CHR region. This study demonstrates that N-peptides with the coiled triple helix structure obtained from the NHR region in 6-HB are able to target the CHR region and exhibit inhibitory activity against a variety of viruses. Moreover, this strategy can be used to investigate antivirals against unknown viruses for future outbreaks.

Orthoflavivirus Lammi in Russia: Possible Transovarial Transmission and Trans-Stadial Survival in Aedes cinereus (Diptera, Culicidae).

In the last few years, there has been a dramatic increase in the number of discovered viruses that are transmitted by arthropods. Some of them are pathogenic for humans and mammals, and the pathogenic potential of others is unknown. The genus Orthoflavivirus belongs to the family Flaviviridae and includes arboviruses that cause severe human diseases with damage to the central nervous system and hemorrhagic fevers, as well as viruses with unknown vectors and viruses specific only to insects. The latter group includes Lammi virus, first isolated from a mosquito pool in Finland. It is known that Lammi virus successfully replicates in mosquito cell lines but not in mammalian cell cultures or mice. Lammi virus reduces the reproduction of West Nile virus during superinfection and thus has the potential to reduce the spread of West Nile virus in areas where Lammi virus is already circulating. In this work, we isolated Lammi virus from a pool of adult Aedes cinereus mosquitoes that hatched from larvae/pupae collected in Saint Petersburg, Russia. This fact may indicate transovarial transmission and trans-stadial survival of the virus.

Evaluation of Mastadenovirus and Rotavirus Presence in Phyllostomid, Vespertilionid, and Molossid Bats Captured in Rio Grande do Sul, Southern Brazil.

Bat-borne viruses may affect public health and the global economy. These mammals have a wide geographical distribution and unique biological, physiological, and immunogenic characteristics, allowing the dissemination of many known and unknown viruses. Enteric viruses, such as adeno (AdV) and rotaviruses, are recognized as the main causative agents of disease and outbreaks. In the present study, the presence of viruses from Adenoviridae and Reoviridae families was evaluated in molossid, phyllostomid, and vespertilionid bats captured in Rio Grande do Sul, Southern Brazil, between September 2021 and July 2022. Sixty bat rectal swabs were analyzed by PCR. Eight (13.3%) samples were positive for adenovirus and classified as human mastadenovirus C (HAdV-C) (three samples) and HAdV-E (five samples) by sequencing followed by phylogenetic analysis. All samples were negative in rotavirus specific RT-PCR. This is the first study to describe the presence of HAdV in samples of Glossophaga soricina, Eptesicus brasiliensis, and Histiotus velatus. Furthermore, the presence of HAdV-E in bats was reported, which is unusual and may suggest that other HAdV genotypes, in addition to HAdV-C, may also be harbored by wild animals. The data generated in the present study reinforces the importance of eco-surveillance of viral agents related to diseases in humans and wild animals. In addition, it is essential to identify possible new hosts or reservoirs that increase the risk of spillover and dissemination of infectious pathogens, helping to prevent and control zoonotic diseases.

Discovery and characterization of novel DNA viruses in Apis mellifera: expanding the honey bee virome through metagenomic analysis.

To date, many viruses have been discovered to infect honey bees. In this study, we used high-throughput sequencing to expand the known virome of the honey bee, Apis mellifera, by identifying several novel DNA viruses. While the majority of previously identified bee viruses are RNA, our study reveals nine new genomes from the Parvoviridae family, tentatively named Bee densoviruses 1 to 9. In addition, we characterized a large DNA virus, Apis mellifera filamentous-like virus (AmFLV), which shares limited protein identities with the known Apis mellifera filamentous virus. The complete sequence of AmFLV, obtained by a combination of laboratory techniques and bioinformatics, spans 152,678 bp. Linear dsDNA genome encodes for 112 proteins, of which 49 are annotated. Another large virus we discovered is Apis mellifera nudivirus, which belongs to a group of Alphanudivirus. The virus has a length of 129,467 bp and a circular dsDNA genome, and has 106 protein encoding genes. The virus contains most of the core genes of the family Nudiviridae. This research demonstrates the effectiveness of viral binning in identifying viruses in honey bee virology, showcasing its initial application in this field.IMPORTANCEHoney bees contribute significantly to food security by providing pollination services. Understanding the virome of honey bees is crucial for the health and conservation of bee populations and also for the stability of the ecosystems and economies for which they are indispensable. This study unveils previously unknown DNA viruses in the honey bee virome, expanding our knowledge of potential threats to bee health. The use of the viral binning approach we employed in this study offers a promising method to uncovering and understanding the vast viral diversity in these essential pollinators.