204 research outputs found

    International Network for Capacity Building for the Control of Emerging Viral Vector-Borne Zoonotic Diseases: Arbo-Zoonet

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    Arboviruses are arthropod-borne viruses, which include West Nile fever virus (WNFV), a mosquito-borne virus, Rift Valley fever virus (RVFV), a mosquito-borne virus, and Crimean-Congo haemorrhagic fever virus (CCHFV), a tick-borne virus. These arthropod-borne viruses can cause disease in different domestic and wild animals and in humans, posing a threat to public health because of their epidemic and zoonotic potential. In recent decades, the geographical distribution of these diseases has expanded. Outbreaks of WNF have already occurred in Europe, especially in the Mediterranean basin. Moreover, CCHF is endemic in many European countries and serious outbreaks have occurred, particularly in the Balkans, Turkey and Southern Federal Districts of Russia. In 2000, RVF was reported for the first time outside the African continent, with cases being confirmed in Saudi Arabia and Yemen. This spread was probably caused by ruminant trade and highlights that there is a threat of expansion of the virus into other parts of Asia and Europe. In the light of global warming and globalisation of trade and travel, public interest in emerging zoonotic diseases has increased. This is especially evident regarding the geographical spread of vector-borne diseases. A multi-disciplinary approach is now imperative, and groups need to collaborate in an integrated manner that includes vector control, vaccination programmes, improved therapy strategies, diagnostic tools and surveillance, public awareness, capacity building and improvement of infrastructure in endemic regions

    ΠžΡ€Π³Π°Π½Ρ–Π·Π°Ρ†Ρ–ΠΉΠ½ΠΎ-Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–Ρ‡Π½Ρ– основи Ρ€ΠΎΠ·Π²ΠΈΡ‚ΠΊΡƒ ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΎΡ— Π²Ρ–Π΄ΠΏΠΎΠ²Ρ–Π΄Π°Π»ΡŒΠ½ΠΎΡΡ‚Ρ– промисловго підприємства

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    Бучасний Π΅Ρ‚Π°ΠΏ Ρ€ΠΎΠ·Π²ΠΈΡ‚ΠΊΡƒ ΡΡƒΡΠΏΡ–Π»ΡŒΡΡ‚Π²Π° Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ·ΡƒΡ”Ρ‚ΡŒΡΡ суттєвими Π·ΠΌΡ–Π½Π°ΠΌΠΈ Π² усіх сфСрах ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ Ρ‚Π° Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–Ρ‡Π½ΠΎΠ³ΠΎ Тиття. Π”ΠΎΠ²Π³ΠΎΡ‚Ρ€ΠΈΠ²Π°Π»ΠΈΠΉ Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–Ρ‡Π½ΠΈΠΉ спад після відновлСння нСзалСТності Π£ΠΊΡ€Π°Ρ—Π½ΠΈ ΠΎΠ±ΡƒΠΌΠΎΠ²ΠΈΠ² зниТСння ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΎΡ— активності підприємств, Π° сучасні ΠΊΡ€ΠΈΠ·ΠΎΠ²Ρ– Ρ‚Π΅Π½Π΄Π΅Π½Ρ†Ρ–Ρ— Π½Π΅Π³Π°Ρ‚ΠΈΠ²Π½ΠΎ ΠΏΠΎΠ·Π½Π°Ρ‡Π°ΡŽΡ‚ΡŒΡΡ Π½Π° Π²ΠΈΠΊΠΎΠ½Π°Π½Π½Ρ– ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΈΡ… Ρ„ΡƒΠ½ΠΊΡ†Ρ–ΠΉ Π΄Π΅Ρ€ΠΆΠ°Π²ΠΎΡŽ. Π¦Π΅, поряд Π· постійними трансформаційними процСсами, ΠΏΡ€ΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚ΡŒ Π΄ΠΎ зниТСння якості Тиття ΠΉ Π½Π΅Π³Π°Ρ‚ΠΈΠ²Π½ΠΎ Π²ΠΏΠ»ΠΈΠ²Π°Ρ” Π½Π° Ρ€ΠΎΠ·Π²ΠΈΡ‚ΠΎΠΊ Π΅ΠΊΠΎΠ½ΠΎΠΌΡ–ΠΊΠΈ. ВпровадТСння ΠΏΡ€ΠΈΠ½Ρ†ΠΈΠΏΡ–Π² ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΎΡ— Π²Ρ–Π΄ΠΏΠΎΠ²Ρ–Π΄Π°Π»ΡŒΠ½ΠΎΡΡ‚Ρ– Π² бізнСс- процСси виступає Ρ‡ΠΈΠ½Π½ΠΈΠΊΠΎΠΌ подальшого Ρ€ΠΎΠ·Π²ΠΈΡ‚ΠΊΡƒ підприємства Ρ‚Π° Π½Π°Π±ΡƒΠ²Π°Ρ” ΠΏΠ΅Ρ€ΡˆΠΎΡ‡Π΅Ρ€Π³ΠΎΠ²ΠΎΠ³ΠΎ значСння ΠΏΡ€ΠΈ Π²ΠΈΡ€Ρ–ΡˆΠ΅Π½Π½Ρ– ряду ΡΠΎΡ†Ρ–Π°Π»ΡŒΠ½ΠΈΡ… ΠΏΡ€ΠΎΠ±Π»Π΅ΠΌ. ΠŸΡ€ΠΈ Ρ†ΠΈΡ‚ΡƒΠ²Π°Π½Π½Ρ– Π΄ΠΎΠΊΡƒΠΌΠ΅Π½Ρ‚Π°, використовуйтС посилання http://essuir.sumdu.edu.ua/handle/123456789/1581

    Schmallenberg virus pathogenesis, tropism and interaction with the innate immune system of the host

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    Schmallenberg virus (SBV) is an emerging orthobunyavirus of ruminants associated with outbreaks of congenital malformations in aborted and stillborn animals. Since its discovery in November 2011, SBV has spread very rapidly to many European countries. Here, we developed molecular and serological tools, and an experimental in vivo model as a platform to study SBV pathogenesis, tropism and virus-host cell interactions. Using a synthetic biology approach, we developed a reverse genetics system for the rapid rescue and genetic manipulation of SBV. We showed that SBV has a wide tropism in cell culture and β€œsynthetic” SBV replicates in vitro as efficiently as wild type virus. We developed an experimental mouse model to study SBV infection and showed that this virus replicates abundantly in neurons where it causes cerebral malacia and vacuolation of the cerebral cortex. These virus-induced acute lesions are useful in understanding the progression from vacuolation to porencephaly and extensive tissue destruction, often observed in aborted lambs and calves in naturally occurring Schmallenberg cases. Indeed, we detected high levels of SBV antigens in the neurons of the gray matter of brain and spinal cord of naturally affected lambs and calves, suggesting that muscular hypoplasia observed in SBV-infected lambs is mostly secondary to central nervous system damage. Finally, we investigated the molecular determinants of SBV virulence. Interestingly, we found a biological SBV clone that after passage in cell culture displays increased virulence in mice. We also found that a SBV deletion mutant of the non-structural NSs protein (SBVΞ”NSs) is less virulent in mice than wild type SBV. Attenuation of SBV virulence depends on the inability of SBVΞ”NSs to block IFN synthesis in virus infected cells. In conclusion, this work provides a useful experimental framework to study the biology and pathogenesis of SBV

    DNA intercalator stimulates influenza transcription and virus replication

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    Influenza A virus uses its host transcription machinery to facilitate viral RNA synthesis, an event that is associated with cellular RNA polymerase II (RNAPII). In this study, various RNAPII transcription inhibitors were used to investigate the effect of RNAPII phosphorylation status on viral RNA transcription. A low concentration of DNA intercalators, such as actinomycin D (ActD), was found to stimulate viral polymerase activity and virus replication. This effect was not observed in cells treated with RNAPII kinase inhibitors. In addition, the loss of RNAPIIa in infected cells was due to the shift of nonphosphorylated RNAPII (RNAPIIa) to hyperphosphorylated RNAPII (RNAPIIo)

    Tissue Tropism and Target Cells of NSs-Deleted Rift Valley Fever Virus in Live Immunodeficient Mice

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    Rift Valley fever, caused by a member of the Bunyaviridae family, has spread during recent years to most sub-Saharan African countries, in Egypt and in the Arabian peninsula. The virus can be transmitted by insect vectors or by direct contacts with infectious tissues. The analysis of virus replication and dissemination in laboratory animals has been hampered by the need to euthanize sufficient numbers of animals and to assay appropriate organs at various time points after infection to evaluate the viral replication. By following the bioluminescence and fluorescence of Rift Valley fever viruses expressing light reporters, we were able to track the real-time dissemination of the viruses in live immunodeficient mice. We showed that the first infected organs were the thymus, spleen and liver, but the liver rapidly became the main location of viral replication. Phagocytes also appeared as important targets, and their systemic depletion by use of clodronate liposomes decreased the number of viruses in the blood, delayed the viral dissemination and prolonged the survival of the infected mice

    Infection and Transmission of Rift Valley Fever Viruses Lacking the NSs and/or NSm Genes in Mosquitoes: Potential Role for NSm in Mosquito Infection

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    Rift Valley fever virus is transmitted mainly by mosquitoes and causes disease in humans and animals throughout Africa and the Arabian Peninsula. The impact of disease is large in terms of human illness and mortality, and economic impact on the livestock industry. For these reasons, and because there is a risk of this virus spreading to Europe and North America, it is important to develop a vaccine that is stable, safe and effective in preventing infection. Potential vaccine viruses have been developed through deletion of two genes (NSs and NSm) affecting virus virulence. Because this virus is normally transmitted by mosquitoes we must determine the effects of the deletions in these vaccine viruses on their ability to infect and be transmitted by mosquitoes. An optimal vaccine virus would not infect or be transmitted. The viruses were tested in two mosquito species: Aedes aegypti and Culex quinquefasciatus. Deletion of the NSm gene reduced infection of Ae. aegypti mosquitoes indicating a role for the NSm protein in mosquito infection. The virus with deletion of both NSs and NSm genes was the best vaccine candidate since it did not infect Ae. aegypti and showed reduced infection and transmission rates in Cx. quinquefasciatus

    p53 Activation following Rift Valley Fever Virus Infection Contributes to Cell Death and Viral Production

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    Rift Valley fever virus (RVFV) is an emerging viral zoonosis that is responsible for devastating outbreaks among livestock and is capable of causing potentially fatal disease in humans. Studies have shown that upon infection, certain viruses have the capability of utilizing particular cellular signaling pathways to propagate viral infection. Activation of p53 is important for the DNA damage signaling cascade, initiation of apoptosis, cell cycle arrest and transcriptional regulation of multiple genes. The current study focuses on the role of p53 signaling in RVFV infection and viral replication. These results show an up-regulation of p53 phosphorylation at several serine sites after RVFV MP-12 infection that is highly dependent on the viral protein NSs. qRT-PCR data showed a transcriptional up-regulation of several p53 targeted genes involved in cell cycle and apoptosis regulation following RVFV infection. Cell viability assays demonstrate that loss of p53 results in less RVFV induced cell death. Furthermore, decreased viral titers in p53 null cells indicate that RVFV utilizes p53 to enhance viral production. Collectively, these experiments indicate that the p53 signaling pathway is utilized during RVFV infection to induce cell death and increase viral production

    Innate Immune Response to Rift Valley Fever Virus in Goats

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    Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-Ξ³, IL-12 and other proinflammatory cytokines but not IFN-Ξ±. Despite the lack of IFN-Ξ±, innate immunity via the IL-12 to IFN-Ξ³ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings
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