scholarly journals Recent advances in the molecular and cellular biology of bunyaviruses

2011 ◽  
Vol 92 (11) ◽  
pp. 2467-2484 ◽  
Author(s):  
Cheryl T. Walter ◽  
John N. Barr
Keyword(s):  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Emerging Viruses ◽  
Valley Fever ◽  
Hemorrhagic Fever Virus ◽  
Recent Advances ◽  
Causative Agents ◽  
Serious Disease ◽  
Global Threat

The family Bunyaviridae of segmented, negative-stranded RNA viruses includes over 350 members that infect a bewildering variety of animals and plants. Many of these bunyaviruses are the causative agents of serious disease in their respective hosts, and are classified as emerging viruses because of their increased incidence in new populations and geographical locations throughout the world. Emerging bunyaviruses, such as Crimean–Congo hemorrhagic fever virus, tomato spotted wilt virus and Rift Valley fever virus, are currently attracting great interest due to migration of their arthropod vectors, a situation possibly linked to climate change. These and other examples of continued emergence suggest that bunyaviruses will probably continue to pose a sustained global threat to agricultural productivity, animal welfare and human health. The threat of emergence is particularly acute in light of the lack of effective preventative or therapeutic treatments for any of these viruses, making their study an important priority. This review presents recent advances in the understanding of the bunyavirus life cycle, including aspects of their molecular, cellular and structural biology. Whilst special emphasis is placed upon the emerging bunyaviruses, we also describe the extensive body of work involving model bunyaviruses, which have been the subject of major contributions to our overall understanding of this important group of viruses.

scholarly journals First Serological Evidence of Crimean-Congo Hemorrhagic Fever Virus and Rift Valley Fever Virus in Ruminants in Tunisia

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 769
Author(s):  
Khaoula Zouaghi ◽  
Ali Bouattour ◽  
Hajer Aounallah ◽  
Rebecca Surtees ◽  
Eva Krause ◽  
...  
Keyword(s):  
Risk Factors ◽  
Potential Risk ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Valley Fever ◽  
Hemorrhagic Fever Virus ◽  
Potential Risk Factors

Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley fever virus (RVFV, Phenuiviridae family) are zoonotic vector-borne pathogens with clinical relevance worldwide. Our study aimed to determine seroprevalences of these viruses and potential risk factors among livestock (cattle, sheep, and goats) in Tunisia. Sera were tested for antibodies against CCHFV (n = 879) and RVFV (n = 699) using various enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence assays (IIFA). The overall seroprevalence of IgG antibodies was 8.6% (76/879) and 2.3% (16/699) against CCHFV and RVFV, respectively. For CCHF seropositivity bioclimatic zones and breed were potential risk factors for the three tested animal species; while the season was associated with cattle and sheep seropositivity, tick infestation was associated with cattle and goats seropositivity and age as a risk factor was only associated with cattle seropositivity. Age and season were significantly associated with RVFV seropositivity in sheep. Our results confirm the circulation of CCHFV and RVFV in Tunisia and identified the principal risk factors in ruminants. This knowledge could help to mitigate the risk of ruminant infections and subsequently also human infections.

scholarly journals Hemorrhagic fever in Saudi Arabia: challenge to public health, effective management and future considerations

2020 ◽  
Vol 20 (3) ◽  
pp. 1153-1163
Author(s):  
Taha A Kumosani ◽  
Abdulrahman L Al-Malki ◽  
Syed S Razvi ◽  
Maha J Balgoon ◽  
Mohammed Kaleem ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Surveillance Systems ◽  
Valley Fever ◽  
Government Organizations ◽  
Response Strategies ◽  
Hemorrhagic Fever Virus ◽  
Diagnostic Facility

Background: Viral hemorrhagic fevers (VHF) refers to a group of febrile illnesses caused by different viruses that result in high mortality in animals and humans. Many risk factors like increased human-animal interactions, climate change, increased mobility of people and limited diagnostic facility have contributed to the rapid spread of VHF. Materials: The history of VHFs in the Saudi Arabian Peninsula has been documented since the 19th century, in which many outbreaks have been reported from the southwestern region of Saudi Arabia. Despite presence of regional network of experts and technical organizations, which expedite support and respond during outbreaks, there are some more challenges that need to be addressed immediately. Gaps in funding, exhaustive and inclusive response plans and improved surveillance systems are some areas of concern in the region which can be dealt productively. This review primarily focusses on the hem- orrhagic fevers that are caused by three most common viruses namely, the Alkhurma hemorrhagic fever virus, Rift valley fever virus, and Dengue fever virus. Conclusion: In summary, effective vector control, health education, possible use of vaccine and concerted synchronized efforts between different government organizations and private research institutions will help in planning effective out- break-prevention and response strategies in future. Keywords: Viral fever; hemorrhagic fever (VHF); Saudi Arabia; challenges; management; future considerations.

scholarly journals A ΩXaV motif in the Rift Valley fever virus NSs protein is essential for degrading p62, forming nuclear filaments and virulence

2015 ◽  
Vol 112 (19) ◽  
pp. 6021-6026 ◽  
Author(s):  
Normand Cyr ◽  
Cynthia de la Fuente ◽  
Lauriane Lecoq ◽  
Irene Guendel ◽  
Philippe R. Chabot ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Excision Repair ◽  
Rna Virus ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Valley Fever ◽  
Infected Cells

Rift Valley fever virus (RVFV) is a single-stranded RNA virus capable of inducing fatal hemorrhagic fever in humans. A key component of RVFV virulence is its ability to form nuclear filaments through interactions between the viral nonstructural protein NSs and the host general transcription factor TFIIH. Here, we identify an interaction between a ΩXaV motif in NSs and the p62 subunit of TFIIH. This motif in NSs is similar to ΩXaV motifs found in nucleotide excision repair (NER) factors and transcription factors known to interact with p62. Structural and biophysical studies demonstrate that NSs binds to p62 in a similar manner as these other factors. Functional studies in RVFV-infected cells show that the ΩXaV motif is required for both nuclear filament formation and degradation of p62. Consistent with the fact that the RVFV can be distinguished from otherBunyaviridae-family viruses due to its ability to form nuclear filaments in infected cells, the motif is absent in the NSs proteins of otherBunyaviridae-family viruses. Taken together, our studies demonstrate that p62 binding to NSs through the ΩXaV motif is essential for degrading p62, forming nuclear filaments and enhancing RVFV virulence. In addition, these results show how the RVFV incorporates a simple motif into the NSs protein that enables it to functionally mimic host cell proteins that bind the p62 subunit of TFIIH.

scholarly journals Results of tick testing for detection of viruses of Karshi, Tamdy, Issyk-Kul fever, Syr Darya valley fever

2021 ◽  
Vol 102 (2) ◽  
pp. 43-50
Author(s):  
Talgat Nurmakhanov ◽  
◽  
Toktasyn Erubaev ◽  
Yerlan Sansyzbaev ◽  
Nurkeldy Turebekov ◽  
...  
Keyword(s):  
Molecular Genetic ◽  
Hemorrhagic Fever ◽  
Molecular Genetic Analysis ◽  
Fever Virus ◽  
Valley Fever ◽  
Crimean Congo Hemorrhagic Fever ◽  
Hemorrhagic Fever Virus ◽  
The Crimea ◽  
Natural Foci ◽  
Syr Darya

In Kazakhstan natural foci of Crimea-Congo hemorrhagic fever is located on the territory of Turkestan, Kyzylorda and Zhambyl regions. Whereas preventive measures are taken, this disease is diagnosed annually among people, but there is a group of viruses such as Karshi, Tamdy, the Issyk-Kul fever virus and Syr Darya valley fever which are less known. In this regard the goal was set to identify the prevalence of viruses of Karshi, Tamdy, Issyk-Kul fever and fever of the Syr Darya valley in hemorrhagic fever endemic in the Crimea-Congo hemorrhagic fever to determine the main hosts and vectors of infection. Ticks captured in areas natural foci of the Crimean-Congo hemorrhagic fever virus. The species composition of captured ticks was represented by 9 species: Hyalomma scupense, Hyalomma asiaticum, Hyalomma turanicum, Hyalomma anatolicum, Haemaphysalis sucata, Haemaphysalis punctata, Dermacentor niveus, Rhipicephalus pumilio, Rhipicephalus schulzei. Preliminary work was carried out on the selection and design of oligonucleotide primers for the identification of viruses by molecular genetic analysis. As a result of the studies, positive samples were found for viruses of Tamdy and Syr Darya valley fever in ticks H. asiaticum, H. scupense from the Turkestan region. The Crimean-Congo hemorrhagic fever virus was detected in H. asiaticum and H. scupense ticks from Zhambyl and Turkestan regions.

scholarly journals A Haploid Genetic Screen Identifies Heparan Sulfate Proteoglycans Supporting Rift Valley Fever Virus Infection

2015 ◽  
Vol 90 (3) ◽  
pp. 1414-1423 ◽  
Author(s):  
Amber M. Riblett ◽  
Vincent A. Blomen ◽  
Lucas T. Jae ◽  
Louis A. Altamura ◽  
Robert W. Doms ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Golgi Complex ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Cell Types ◽  
Fever Virus ◽  
Host Cells ◽  
Valley Fever

ABSTRACTRift Valley fever virus (RVFV) causes recurrent insect-borne epizootics throughout the African continent, and infection of humans can lead to a lethal hemorrhagic fever syndrome. Deep mutagenesis of haploid human cells was used to identify host factors required for RVFV infection. This screen identified a suite of enzymes involved in glycosaminoglycan (GAG) biogenesis and transport, including several components of thecis-oligomeric Golgi (COG) complex, one of the central components of Golgi complex trafficking. In addition, disruption ofPTAR1led to RVFV resistance as well as reduced heparan sulfate surface levels, consistent with recent observations that PTAR1-deficient cells exhibit altered Golgi complex morphology and glycosylation defects. A variety of biochemical and genetic approaches were utilized to show that both pathogenic and attenuated RVFV strains require GAGs for efficient infection on some, but not all, cell types, with the block to infection being at the level of virion attachment. Examination of other members of theBunyaviridaefamily for GAG-dependent infection suggested that the interaction with GAGs is not universal among bunyaviruses, indicating that these viruses, as well as RVFV on certain cell types, employ additional unidentified virion attachment factors and/or receptors.IMPORTANCERift Valley fever virus (RVFV) is an emerging pathogen that can cause severe disease in humans and animals. Epizootics among livestock populations lead to high mortality rates and can be economically devastating. Human epidemics of Rift Valley fever, often initiated by contact with infected animals, are characterized by a febrile disease that sometimes leads to encephalitis or hemorrhagic fever. The global burden of the pathogen is increasing because it has recently disseminated beyond Africa, which is of particular concern because the virus can be transmitted by widely distributed mosquito species. There are no FDA-licensed vaccines or antiviral agents with activity against RVFV, and details of its life cycle and interaction with host cells are not well characterized. We used the power of genetic screening in human cells and found that RVFV utilizes glycosaminoglycans to attach to host cells. This furthers our understanding of the virus and informs the development of antiviral therapeutics.

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