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Emerging Infectious Diseases May 2016
Topics: Humans; Orthobunyavirus; Terminology as Topic
PubMed: 27551714
DOI: 10.3201/eid2205.et2205 -
Revue Scientifique Et Technique... Aug 2015Since Schmallenberg virus, an orthobunyavirus of the Simbu serogroup, was identified near the German-Dutch border for the first time in late 2011 it has spread extremely...
Since Schmallenberg virus, an orthobunyavirus of the Simbu serogroup, was identified near the German-Dutch border for the first time in late 2011 it has spread extremely quickly and caused a large epidemic in European livestock. The virus, which is transmitted by Culicoides biting midges, infects domestic and wild ruminants. Adult animals show only mild clinical symptoms or none at all, whereas an infection during a critical period of gestation can lead to abortion, stillbirth or the birth of severely malformed offspring. The impact of the disease is usually greater in sheep than in cattle. Vaccination could be an important aspect of disease control.
Topics: Animals; Bunyaviridae Infections; Orthobunyavirus; Ruminants
PubMed: 26601441
DOI: 10.20506/rst.34.2.2363 -
Cell Reports Mar 2023La Crosse virus, responsible for pediatric encephalitis in the United States, and Schmallenberg virus, a highly teratogenic veterinary virus in Europe, belong to the...
La Crosse virus, responsible for pediatric encephalitis in the United States, and Schmallenberg virus, a highly teratogenic veterinary virus in Europe, belong to the large Orthobunyavirus genus of zoonotic arthropod-borne pathogens distributed worldwide. Viruses in this under-studied genus cause CNS infections or fever with debilitating arthralgia/myalgia syndromes, with no effective treatment. The main surface antigen, glycoprotein Gc (∼1,000 residues), has a variable N-terminal half (Gc) targeted by the patients' antibody response and a conserved C-terminal moiety (Gc) responsible for membrane fusion during cell entry. Here, we report the X-ray structure of post-fusion La Crosse and Schmallenberg virus Gc, revealing the molecular determinants for hairpin formation and trimerization required to drive membrane fusion. We further experimentally confirm the role of residues in the fusion loops and in a vestigial endoplasmic reticulum (ER) translocation sequence at the Gc-Gc junction. The resulting knowledge provides essential molecular underpinnings for future development of potential therapeutic treatments and vaccines.
Topics: Humans; Child; Orthobunyavirus; Membrane Glycoproteins; Membrane Fusion; Glycoproteins; La Crosse virus
PubMed: 36827185
DOI: 10.1016/j.celrep.2023.112142 -
The Veterinary Record Aug 2014British sheep farmers were invited to complete a questionnaire about the impact of Schmallenberg virus (SBV) on animal health, welfare and their own emotional wellbeing...
British sheep farmers were invited to complete a questionnaire about the impact of Schmallenberg virus (SBV) on animal health, welfare and their own emotional wellbeing during the 2011-2012 lambing season, through Defra and Farming Industry websites, letters to farmers who had requested SBV laboratory tests and advertisement at Sheep 2012. The 494 responders included SBV confirmed (positive by RT-PCR) (n=76), SBV suspected by farmer (n=140) or SBV not suspected (n=278). Percentage of barren ewes was similar across SBV groups, however, lamb and ewe losses were higher on responder farms where SBV was confirmed or suspected. The median percentages of all lambs born (and lambs born deformed ) that died within one week of birth was 10.4 per cent (5.5 per cent), 7.0 per cent (2.9 per cent) and 5.3 per cent (0 per cent), respectively, on SBV confirmed, suspected and not suspected farms (P<0.001). Eight to 16 per cent of SBV confirmed or suspected farms reported lamb mortality of ≥40 per cent. Farmer perceived impact was greater where SBV was confirmed or suspected (P<0.001): 25 per cent reported a high impact on emotional wellbeing (4 per cent of SBV not suspected), 13 per cent reported a high impact on flock welfare and financial performance and 6 per cent were less likely to farm sheep next year because of SBV (<2 per cent in SBV not suspected). Overall, SBV impact has been large relative to reported sheep loss.
Topics: Agriculture; Animals; Bunyaviridae Infections; Cost of Illness; Female; Orthobunyavirus; Pregnancy; Seasons; Sheep; Sheep Diseases; United Kingdom
PubMed: 24795165
DOI: 10.1136/vr.102295 -
Journal of Virology Mar 2022With more than 80 members worldwide, the genus in the family is a large genus of enveloped RNA viruses, many of which are emerging pathogens in humans and livestock....
With more than 80 members worldwide, the genus in the family is a large genus of enveloped RNA viruses, many of which are emerging pathogens in humans and livestock. How orthobunyaviruses (OBVs) penetrate and infect mammalian host cells remains poorly characterized. Here, we investigated the entry mechanisms of the OBV Germiston (GERV). Viral particles were visualized by cryo-electron microscopy and appeared roughly spherical with an average diameter of 98 nm. Labeling of the virus with fluorescent dyes did not adversely affect its infectivity and allowed the monitoring of single particles in fixed and live cells. Using this approach, we found that endocytic internalization of bound viruses was asynchronous and occurred within 30 to 40 min. The virus entered Rab5a-positive (Rab5a) early endosomes and, subsequently, late endosomal vacuoles containing Rab7a but not LAMP-1. Infectious entry did not require proteolytic cleavage, and endosomal acidification was sufficient and necessary for viral fusion. Acid-activated penetration began 15 to 25 min after initiation of virus internalization and relied on maturation of early endosomes to late endosomes. The optimal pH for viral membrane fusion was slightly below 6.0, and penetration was hampered when the potassium influx was abolished. Overall, our study provides real-time visualization of GERV entry into host cells and demonstrates the importance of late endosomal maturation in facilitating OBV penetration. Orthobunyaviruses (OBVs), which include La Crosse, Oropouche, and Schmallenberg viruses, represent a growing threat to humans and domestic animals worldwide. Ideally, preventing OBV spread requires approaches that target early stages of infection, i.e., virus entry. However, little is known about the molecular and cellular mechanisms by which OBVs enter and infect host cells. Here, we developed accurate, sensitive tools and assays to investigate the penetration process of GERV. Our data emphasize the central role of late endosomal maturation in GERV entry, providing a comprehensive overview of the early stages of an OBV infection. Our study also brings a complete toolbox of innovative methods to study each step of the OBV entry program in fixed and living cells, from virus binding and endocytosis to fusion and penetration. The information gained herein lays the foundation for the development of antiviral strategies aiming to block OBV entry.
Topics: Animals; Cryoelectron Microscopy; Endosomes; Mammals; Orthobunyavirus; Virus Internalization
PubMed: 35019710
DOI: 10.1128/jvi.02146-21 -
Viruses Jul 2016The Bunyaviridae is a family of arboviruses including both plant- and vertebrate-infecting representatives. The Tospovirus genus accommodates plant-infecting... (Review)
Review
The Bunyaviridae is a family of arboviruses including both plant- and vertebrate-infecting representatives. The Tospovirus genus accommodates plant-infecting bunyaviruses, which not only replicate in their plant host, but also in their insect thrips vector during persistent propagative transmission. For this reason, they are generally assumed to encounter antiviral RNA silencing in plants and insects. Here we present an overview on how tospovirus nonstructural NSs protein counteracts antiviral RNA silencing in plants and what is known so far in insects. Like tospoviruses, members of the related vertebrate-infecting bunyaviruses classified in the genera Orthobunyavirus, Hantavirus and Phlebovirus also code for a NSs protein. However, for none of them RNA silencing suppressor activity has been unambiguously demonstrated in neither vertebrate host nor arthropod vector. The second part of this review will briefly describe the role of these NSs proteins in modulation of innate immune responses in mammals and elaborate on a hypothetical scenario to explain if and how NSs proteins from vertebrate-infecting bunyaviruses affect RNA silencing. If so, why this discovery has been hampered so far.
Topics: Animals; Gene Silencing; Host-Pathogen Interactions; Immune Evasion; Immunity, Innate; Insecta; Orthobunyavirus; Plants; RNA, Viral; Thysanoptera; Vertebrates; Viral Nonstructural Proteins
PubMed: 27455310
DOI: 10.3390/v8070208 -
Oncotarget Dec 2015
Topics: Animals; Arenaviridae; Filoviridae; Flaviviridae; Hemorrhagic Fevers, Viral; Host-Pathogen Interactions; Humans; Immune Tolerance; Immunity, Innate; Orthobunyavirus; Signal Transduction
PubMed: 26657729
DOI: 10.18632/oncotarget.6509 -
Veterinary Medicine and Science Sep 2022Akabane virus (AKAV) is a teratogenic and neuropathogenic arbovirus that infects livestock and wild animals. AKAVs are endemic arboviruses from dairy farms in Taiwan in...
BACKGROUND
Akabane virus (AKAV) is a teratogenic and neuropathogenic arbovirus that infects livestock and wild animals. AKAVs are endemic arboviruses from dairy farms in Taiwan in 1989, and the first sequence was detected in cattle with nonsuppurative encephalitis in 1992.
OBJECTIVES
This study aims to understand the epidemiological relationships of the akabane viruses between Taiwan and nearby places.
METHODS
In this study, 17 specimens were identified or isolated from vector insects, and ruminant fetuses collected from 1992 to 2015 were sequenced and analysed.
RESULTS
Sequence analyses revealed all Taiwanese AKAVs belonged to genogroup Ia but diverged into two clusters in the phylogenetic trees, implying that at least two invasive events of AKAV may have occurred in Taiwan.
CONCLUSIONS
The two clusters of AKAVs could still be identified in Taiwan in 2015, and a reassortment event was observed, indicating that the two clusters of AKAVs are already endemic in Taiwan.
Topics: Animals; Arboviruses; Cattle; Cattle Diseases; Molecular Epidemiology; Orthobunyavirus; Phylogeny; Taiwan
PubMed: 35971895
DOI: 10.1002/vms3.887 -
Current Opinion in Virology Feb 2016A novel tick-borne Bunyavirus, discovered in China and later in South Korea and Japan, is now known as Huaiyangshan virus or severe fever with thrombocytopenia syndrome... (Review)
Review
A novel tick-borne Bunyavirus, discovered in China and later in South Korea and Japan, is now known as Huaiyangshan virus or severe fever with thrombocytopenia syndrome virus and has been identified as the causative agent of a hemorrhagic fever-like disease. Of five species of ticks carrying Huaiyangshan viruses, Haemaphysalis longicornis was the most abundant in regions where the virus was endemic. Its usual hosts (cattle, goats, dogs, rats and chickens) tested positive for Huaiyangshan virus RNA and had a high seroprevalence. The distribution of H. longicornis and the migratory routes of four wild fowl across China, South Korea and Japan are coincident. Thus a tick and migratory bird model for the transmission of the Huaiyangshan virus was proposed.
Topics: Animal Migration; Animals; Animals, Domestic; Arachnid Vectors; Birds; Bunyaviridae Infections; China; Communicable Diseases, Emerging; Humans; Orthobunyavirus; Tick-Borne Diseases; Ticks
PubMed: 26949898
DOI: 10.1016/j.coviro.2016.02.006 -
Viruses Nov 2022is an important oomycetous plant pathogen with numerous host plant species, including garden strawberry ( × ) and silver birch (). also hosts mycoviruses, but their...
is an important oomycetous plant pathogen with numerous host plant species, including garden strawberry ( × ) and silver birch (). also hosts mycoviruses, but their phenotypic effects on the host oomycete have not been studied earlier. In the present study, we tested polyethylene glycol (PEG)-induced water stress for virus curing and created an isogenic virus-free isolate for testing viral effects in pair with the original isolate. Phytophthora cactorum bunya-like viruses 1 and 2 (PcBV1 & 2) significantly reduced hyphal growth of the host isolate, as well as sporangia production and size. Transcriptomic and proteomic analyses revealed an increase in the production of elicitins due to bunyavirus infection. However, the presence of bunyaviruses did not seem to alter the pathogenicity of . Virus transmission through anastomosis was unsuccessful in vitro.
Topics: Phytophthora; Proteomics; Gene Expression Profiling; Betula; Orthobunyavirus; Bunyaviridae; Plants
PubMed: 36560602
DOI: 10.3390/v14122596