Relevant bibliographies by topics / Viruses transmission

Academic literature on the topic 'Viruses transmission'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Viruses transmission"

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Shapiro, Craig N. "Transmission of Hepatitis Viruses." Annals of Internal Medicine 120, no. 1 (January 1, 1994): 82. http://dx.doi.org/10.7326/0003-4819-120-1-199401010-00014.

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Golino, D. A., S. T. Sim, M. Cunningham, and A. Rowhani. "TRANSMISSION OF ROSE MOSAIC VIRUSES." Acta Horticulturae, no. 751 (August 2007): 217–24. http://dx.doi.org/10.17660/actahortic.2007.751.26.

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Goodwin, Andrew E., James E. Peterson, Theodore R. Meyers, and David J. Money. "Transmission of Exotic Fish Viruses." Fisheries 29, no. 5 (May 2004): 19–23. http://dx.doi.org/10.1577/1548-8446(2004)29[19:toefv]2.0.co;2.

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W Smith, David. "Sexual transmission of hepatitis viruses." Microbiology Australia 28, no. 1 (2007): 20. http://dx.doi.org/10.1071/ma07019.

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Hepatitis viruses are often not perceived as sexually transmitteddiseases, but sex is an extremely important mode of transmission worldwide for hepatitis B, and it plays a significant role for hepatitis C, hepatitis A and hepatitis D.
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Neumann, Gabriele, and Yoshihiro Kawaoka. "Transmission of influenza A viruses." Virology 479-480 (May 2015): 234–46. http://dx.doi.org/10.1016/j.virol.2015.03.009.

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Webster, Robert G., Gerald B. Sharp, and Eric C. J. Claas. "Interspecies Transmission of Influenza Viruses." American Journal of Respiratory and Critical Care Medicine 152, no. 4_pt_2 (October 1995): S25—S30. http://dx.doi.org/10.1164/ajrccm/152.4_pt_2.s25.

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Campbell, R. N. "FUNGAL TRANSMISSION OF PLANT VIRUSES." Annual Review of Phytopathology 34, no. 1 (September 1996): 87–108. http://dx.doi.org/10.1146/annurev.phyto.34.1.87.

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Fulton, J. P., R. C. Gergerich, and H. A. Scott. "Beetle Transmission of Plant Viruses." Annual Review of Phytopathology 25, no. 1 (September 1987): 111–23. http://dx.doi.org/10.1146/annurev.py.25.090187.000551.

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Mori, Isamu, Yukihiro Nishiyama, Takashi Yokochi, and Yoshinobu Kimura. "Olfactory transmission of neurotropic viruses." Journal of Neurovirology 11, no. 2 (January 2005): 129–37. http://dx.doi.org/10.1080/13550280590922793.

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Franklin, S. P., J. L. Troyer, J. A. Terwee, L. M. Lyren, W. M. Boyce, S. P. D. Riley, M. E. Roelke, K. R. Crooks, and S. VandeWoude. "Frequent Transmission of Immunodeficiency Viruses among Bobcats and Pumas." Journal of Virology 81, no. 20 (August 1, 2007): 10961–69. http://dx.doi.org/10.1128/jvi.00997-07.

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ABSTRACT With the exception of human immunodeficiency virus (HIV), which emerged in humans after cross-species transmissions of simian immunodeficiency viruses from nonhuman primates, immunodeficiency viruses of the family Lentiviridae represent species-specific viruses that rarely cross species barriers to infect new hosts. Among the Felidae, numerous immunodeficiency-like lentiviruses have been documented, but only a few cross-species transmissions have been recorded, and these have not been perpetuated in the recipient species. Lentivirus seroprevalence was determined for 79 bobcats (Lynx rufus) and 31 pumas (Puma concolor) from well-defined populations in Southern California. Partial genomic sequences were subsequently obtained from 18 and 12 seropositive bobcats and pumas, respectively. Genotypes were analyzed for phylogenic relatedness and genotypic composition among the study set and archived feline lentivirus sequences. This investigation of feline immunodeficiency virus infection in bobcats and pumas of Southern California provides evidence that cross-species infection has occurred frequently among these animals. The data suggest that transmission has occurred in multiple locations and are most consistent with the spread of the virus from bobcats to pumas. Although the ultimate causes remain unknown, these transmission events may occur as a result of puma predation on bobcats, a situation similar to that which fostered transmission of HIV to humans, and likely represent the emergence of a lentivirus with relaxed barriers to cross-species transmission. This unusual observation provides a valuable opportunity to evaluate the ecological, behavioral, and molecular conditions that favor repeated transmissions and persistence of lentivirus between species.
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Dissertations / Theses on the topic "Viruses transmission"

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Chaudhuri, Roy R. "Evolution and cross-species transmission of AIDS viruses." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395600.

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Davis, Adam James. "Transcriptional analysis of human immunodeficiency virus type 1 infection following cell-to-cell transmission /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phd2609.pdf.

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Powell, Glen. "Stylet activities and potyvirus transmission by aphids." Thesis, King's College London (University of London), 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283709.

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Ali, Ahmed A. "INTERSPECIES TRANSMISSION AND HOST RESTRICTION OF INFLUENZA A VIRUSES." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354125078.

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Longdon, Ben John. "Evolution and ecology of Drosophila sigma viruses." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5768.

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Insects are host to a diverse range of vertically transmitted micro-organisms, but while their bacterial symbionts are well-studied, little is known about their vertically transmitted viruses. The sigma virus (DMelSV) is currently the only natural hostspecific pathogen to be described in Drosophila melanogaster. In this thesis I have examined; the diversity and evolution of sigma viruses in Drosophila, their transmission and population dynamics, and their ability to host shift. I have described six new rhabdoviruses in five Drosophila species — D. affinis, D. obscura, D. tristis, D. immigrans and D. ananassae — and one in a member of the Muscidae, Muscina stabulans (Chapters two and four). These viruses have been tentatively named as DAffSV, DObsSV, DTriSV, DImmSV, DAnaSV and MStaSV respectively. I sequenced the complete genomes of DObsSV and DMelSV, the L gene from DAffSV and partial L gene sequences from the other viruses. Using this new sequence data I created a phylogeny of the rhabdoviruses (Chapter two). The sigma viruses form a distinct clade which is closely related to the Dimarhabdovirus supergroup, and the high levels of divergence between these viruses suggest that they may deserve to be recognised as a new genus. Furthermore, this analysis produced the most robustly supported phylogeny of the Rhabdoviridae to date, allowing me to reconstruct the major transitions that have occurred during the evolution of the family. This data suggests that the bias towards research into plants and vertebrates means that much of the diversity of rhabdoviruses has been missed, and rhabdoviruses may be common pathogens of insects. In Chapter three I examined whether the new sigma viruses in Drosophila affinis and Drosophila obscura are both vertically transmitted. As is the case for DMelSV, both males and females can transmit these viruses to their offspring. Males transmit lower viral titres through sperm than females transmit through eggs, and a lower proportion of their offspring become infected. I then examined natural populations of D. obscura in the UK; 39% of flies were infected and the viral population shows clear evidence of a recent expansion, with extremely low genetic diversity and a large excess of rare polymorphisms. Using sequence data I estimate that the virus has swept across the UK within the last ~11 years, during which time the viral population size doubled approximately every 9 months. Using simulations based on lab estimates of transmission rates, I show that the biparental mode of transmission allows the virus to invade and rapidly spread through populations, at rates consistent with those measured in the field. Therefore, as predicted by the simulations, the virus has undergone an extremely rapid and recent increase in population size. In Chapter four I investigated for the first time whether vertically transmitted viruses undergo host shifts or cospeciate with their hosts. Using a phylogenetic approach I show that sigma viruses have switched between hosts during their evolutionary history. These results suggest that sigma virus infections may be short-lived in a given host lineage, so that their long-term persistence relies on rare horizontal transmission events between hosts. In Chapter five I examined the ability of three Drosophila sigma viruses to persist and replicate in 51 hosts sampled across the Drosophilidae phylogeny. I used a phylogenetic mixed model to account for the non-independence of host taxa due to common ancestry, which additionally allows integration over the uncertainty in the host phylogeny. In two out of the three viruses there was a negative correlation between viral titre and genetic distance from the natural host. Additionally the host phylogeny explains an extremely high proportion of the variation (after considering genetic distance from the natural host) in the ability of these viruses to replicate in novel hosts (>0.8 for all viruses). There were strong phylogenetic correlations between all the viruses (>0.65 for all pairs), suggesting a given species’ level of resistance to one virus is strongly correlated with its resistance to other viruses. This suggests the host phylogeny, and genetic distance from the natural host, may be important in determining viruses ability to host switch. This work has aimed to address fundamental questions relating to host-parasite coevolution and pathogen emergence. The data presented suggests that sigma viruses are likely to be widespread vertically transmitted insect viruses, which have dynamic interactions with their hosts. These viruses appear to have switched between hosts during their evolutionary history and it is likely the host phylogeny is a determinant of such host shifts.
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Hamdollah-Zadeh, Akram. "Transgenic resistance to pollen transmission of tobacco ringspot virus." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364912.

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Blumenkrantz, Deena. "The cellular and molecular basis of transmission of influenza viruses." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24590.

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Pandemic influenza viruses are responsible for many deaths and much suffering as well as large costs accumulated through healthcare provision and lost productivity. The swine-origin H1N1 influenza virus that was at the root of the pandemic in 2009, although considered mild, in the UK alone caused the deaths of 361 people, subjected 1,700 to critical care and led to hospital admission of 7,879, before summer 2010. This virus is now embedded in the human population and will remain there, inducing further mortality, morbidity, and cost until it is replaced by a new pandemic influenza virus and the cycle repeats. However, if we improve our understanding of the characteristics of virus/host interactions that support transmission, we may be able to identify potentially problematic strains, improve our preparedness and ultimately prevent future pandemics. The ability of an influenza virus to transmit from host to host is multifactorial. One role proven to be important because its inhibition by drugs prevents replication is the ability of neuraminidase (NA) to cleave sialic acid (SA). NAs of recently circulating influenza viruses were analysed with the aim of identifying characteristics that might support new or previous pandemic influenza virus strains. NA stalk truncation, induced by influenza virus transmission through gallinaceous poultry, was found to hinder transmission through the air of an otherwise transmissible virus. While this genetic ablation did not directly affect sialidase activity, when measured using a small soluble substrate, it did reduce the ability of virions to release complex tethered substrates, separate from one another and penetrate through mucus. This work suggests that the next pandemic virus is unlikely to have a short stalk NA. Previously, loss of the ability of NA to haemabsorb (Hb) chicken red blood cells (CRBSs) was associated with the adaptation of an influenza virus from avian to human hosts and a single amino acid mutation was shown to reinstate the haemabsorption ability of an NA from a prototypic pandemic H2N2 virus of avian-origin. This thesis shows that the human-adapted 2009 pandemic N1 NA, which arose from the introduction of an avian influenza virus into swine, did not Hb CRBCs, as expected. However, unexpectedly, many back mutations to make the 2009 N1 resemble an NA that did Hb also did not alter this characteristic. Further investigations showed that some NAs from both avian and swine influenza viruses also did not Hb, despite the fact that NA haemabsorption increased viral growth in airway culture cells. Thus we conclude that loss of Hb occurs within birds, before a virus can cross the species barrier into mammals and this may be due to a reduction, rather than a gain, in activity.
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Yassine, Hadi M. "Studies on Interspecies and Intraspecies Transmission of Influenza A Viruses." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243451078.

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Boone, Stephanie. "The Transmission, Detection and Occurrence of Viruses on Indoor Environmental Fomites." Tucson, Ariz. : University of Arizona, 2006. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1347%5F1%5Fm.pdf&type=application/pdf.

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Webb, Gillian. "Studies on the mechanical transmission of animal viruses by biting flies." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278027.

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Books on the topic "Viruses transmission"

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Kunzru, Hari. Transmission. New York: Dutton, 2004.

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Kunzru, Hari. Transmission. New York: Penguin, 2005.

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Kunzru, Hari. Transmission. London: Hamish Hamilton, 2004.

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Viruses and the environment. 2nd ed. London ; New York: Chapman and Hall, 1995.

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Berencsi III, György, ed. Maternal Fetal Transmission of Human Viruses and their Influence on Tumorigenesis. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4216-1.

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Maternal fetal transmission of human viruses and their influence on tumorigenesis. Dordrecht: Springer, 2012.

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Douglass, William Campbell. Who murdered Africa? [Clayton, Ga: s.n., 1987.

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The sociology of HIV transmission. London: Sage Publications, 1995.

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Clements, A. N., ed. The biology of mosquitoes. Volume 3: Transmission of viruses and interactions with bacteria. Wallingford: CABI, 2012. http://dx.doi.org/10.1079/9781845932428.0000.

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National AIDS Council of Zimbabwe. Zimbabwe: National behavioural change strategy for prevention of sexual transmission of HIV, 2006-2010. Harare]: National AIDS Council, 2006.

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Book chapters on the topic "Viruses transmission"

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Hamilton, R. I. "Virus Transmission." In The Plant Viruses, 245–67. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4684-4937-2_8.

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Murant, A. F., B. Raccah, and T. P. Pirone. "Transmission by Vectors." In The Plant Viruses, 237–73. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4684-7038-3_8.

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Brown, D. J. F., D. L. Trudgill, and W. M. Robertson. "Nepoviruses: Transmission by Nematodes." In The Plant Viruses, 187–209. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4899-1772-0_7.

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Weiss, Robin A. "Oncogenic Viruses and Cancer Transmission." In Cancer Associated Viruses, 101–18. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-1-4614-0016-5_5.

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Gergerich, R. C., and H. A. Scott. "Comoviruses: Transmission, Epidemiology, and Control." In The Plant Viruses, 77–98. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4899-1772-0_4.

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Wensing, A. M. J., I. T. J. M. Benders, and C. A. B. Boucher. "Transmission of Resistant Viruses." In HIV-Infekt, 22–28. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59683-4_4.

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Demler, S. A., G. A. de Zoeten, G. Adam, and K. F. Harris. "Pea Enation Mosaic Enamovirus: Properties and Aphid Transmission." In The Plant Viruses, 303–44. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4899-1772-0_12.

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Duffus, James E. "Whitefly Transmission of Plant Viruses." In Advances in Soil Science, 73–91. New York, NY: Springer New York, 1987. http://dx.doi.org/10.1007/978-1-4612-4712-8_3.

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Robert, Yvon, and Danièle Bourdin. "Aphid Transmission of Potato Viruses." In Virus and Virus-like Diseases of Potatoes and Production of Seed-Potatoes, 195–225. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-007-0842-6_20.

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Mehlhorn, Heinz. "Fleas: Transmission Experiments of Viruses." In Encyclopedia of Parasitology, 1056–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-43978-4_3878.

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Conference papers on the topic "Viruses transmission"

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Myers, Matthew R., C. David Lytle, and Licia B. Routson. "Sensitivity to Pore Geometry of Virus Transmission Through Latex Channels: Experimental Analysis." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2633.

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Abstract Previously published measurements of virus transmission through a channel comprised of two planar sheets of latex material displayed an unexpectedly high transmission rate for large virus residence times in the channel. Additional experiments demonstrated that the elevated transmission rate can be explained as a high sensitivity of virus transport to perturbations in channel geometry, for highly adsorptive viruses.
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Myers, Matthew R., C. David Lytle, and Licia B. Routson. "Sensitivity to Pore Geometry of Virus Transmission Through Latex Channels: Experimental Analysis." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2230.

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Abstract Previously published measurements of virus transmission through a channel comprised of two planar sheets of latex material displayed an unexpectedly high transmission rate for large virus residence times in the channel. Additional experiments demonstrated that the elevated transmission rate can be explained as a high sensitivity of virus transport to perturbations in channel geometry, for highly adsorptive viruses.
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Huang, Luofeng, Seogeng Riyadi, I. Ketut Aria Pria Utama, and Giles Thomas. "Computational Study on the Transmission of COVID-19 Virus Inside a Ship." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-80182.

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Abstract To investigate the operational improvements of vessels under the impact of COVID-19, this work has developed a Computational Fluid Dynamics model combined with Lagrangian particles to study the airborne transmission of COVID-19 viruses inside a ship. Initially a generic model was established to enable validation against experimental results for the diffusion of flu virus in an idealised room. Following this, the room geometry was replaced by the superstructure of a full-scale crew boat. Considering the boat advancing in open water, simulations were conducted to study the particulate flow due to a person coughing and speaking, with the boat’s forward door open and closed. The results have shown that, when the forward door is open, a significant airflow can carry the viruses to make extensive contacts with the passengers. This led to the suggestion of keeping the door closed. However, when the forward door is shut, face-to-face speaking can generate viruses that can float in the air for a long time, and it was found that the viruses mainly stay within a half-meter distance in front of the speaking person, before sinking to attach to the deck. Thus, a social-distancing suggestion on seat arrangement has been highlighted to minimise the risk of contagion. Overall, this work is expected to inform guidelines on hygienic and reconfiguring means for operators to counter COVID-19 and potentially the spread of similar viruses in the future.
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Bagrov, R. A., and V. I. Leunov. "Green peach aphid and potato leafroll virus: transmission and control." In Растениеводство и луговодство. Тимирязевская сельскохозяйственная академия, 2020. http://dx.doi.org/10.26897/978-5-9675-1762-4-2020-178.

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The mechanisms of transmission of potato viruses from plants to aphid vectors and from aphids to uninfected plants are described, including the example of the green peach aphid (Myzus persicae, GPA). Factors affecting the spreading of tuber necrosis and its manifestation on plants infected with potato leafroll virus (PLRV) are discussed. Recommendations for PLRV and GPA control in the field are given.
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Barrett, P. N., G. Wöber, J. Eibl, and F. Dorner. "EFFICIENCY OF STEAM TREATMENT PROCEDURES USED FOR VIRUS INACTIVATION IN HUMAN COAGULATION FACTORS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644152.

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The transmission of viral agents from blood products derived from humanplasma has long been a serious healthproblem for the recipients. The majoragents involved are HBV, nonA nonB, Delta agent and HIV (LAV/HTLV-III). Wehave attempted to design product-specific viral inactivation procedures toprevent such transmission in blood products. Experiments were carried out with HIV, which is the only one of the above viruses which can be propagated and titrated in cell culture, and with a wide range of model viruses. High titre virus was added to blood products, and they were then subjected to different virus inactivation procedures.Heat treatment was carried out in aqueous solution with and without protein-stabilising agents, and it was demonstrated that such agents added toprevent loss of biological activity of blood products also resulted in a stabilisation of contaminating viruses.Therefore steam treatment inactivation procedures have been developed without the addition of such agents. Steam pressure, temperature and time of inactivation are the main variablesand these can be altered for each product to achieve an optimal balance between the degree of virus inactivation and retention of biological activity.It has been shown that each of thedifferent product-specific treatment procedures has a high HIV inactivation capacity.Studies with various model virusesalso demonstrated that the efficiencyof these procedures could be furtherimproved if necessary by altering various parameters such as steam pressure.
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Ali, Mohd Mohsin, Rakesh Chandra Joshi, Malay Kishore Dutta, Radim Burget, and Anzhelika Mezina. "Deep Learning-based Classification of Viruses Using Transmission Electron Microscopy Images." In 2022 45th International Conference on Telecommunications and Signal Processing (TSP). IEEE, 2022. http://dx.doi.org/10.1109/tsp55681.2022.9851305.

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Piët, M. P. J., S. Chin, A. M. Prince, and B. Horowitz. "INACTIVATION OF VIRUSES IN PLASMA ON TREATMENT WITH TRI(N-BUTYL) PHOSPHATE (TNBP) DETERGENT MIXTURES." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644149.

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Treatment of plasma with organic solvent/ detergent mixtures at the time of plasma collection or plasma pooling could reduce the exposure of technical staff to infectious virus and enhance the viral safety of final product. Treatment of plasma for 4 hours with 2% TNBP at 37°C or with 1% TNBP and 1% Tween 80 or Triton X-45 at 30°C resulted in the rapid and complete inactivation of ≥104 tissueculture infectious doses (TCID-50) ofvesicularstomatitis and Sindbis viruses, used as surrogates. TNBP and TNBP/Tween treatment of plasma was shown to inactivate ≥104 TCID-50 of human immunodeficiency virus. TNBPtreatment of plasma contaminated with 106 chimpanzee infectious doses (CID-50) of HBV and 105 CID-50 of NANBHV prevented the transmission of hepatitisto chimpanzees through 6 months follow-up.Immediately following treatment with 2% TNBP, the recovery of AHF, factor IX, factor V, and antithrombin IIIwas 75%,90%, 65% and 100%,respectively. A ⊕90% recovery of AHF was observed with TNBP/detergent mixtures. Treated plasma was fractionated intoAHF and prothrombin complex concentrates, immune globulin, and albumin by published techniques. Prior treatmentwithTNBP or TNBP and detergent did not affect the separations of desired proteins. Therefore, it appears possible to inactivate viruses in plasma prior to execution of standard fractionation procedures. If desirable, products prepared from TNBP-treated plasmacan be subjected to additional procedures to further insure virus safety.
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Schimpf, Kl, H. H. Brackmann, D. Bock, G. Landbeck, E. Lechler, and H. Vinazzer. "NO ANTI-HIV SEROCONVERSION AFTER REPLACEMENT THERAPY WITH STEAM-TREATED FACTOR VIII CONCENTRATE. A STUDY OF 60 PATIENTS WITH HEMOPHILIA A AND VON WILLEBRAND'S DISEASE." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644054.

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Transmission of hepatitis viruses and HIV has proven to be a risk of replacement therapy. Since Dec. 1983 factor VIII concentrates in which viruses are inactivated by steam-treatment (Factor VIII TIM 3 or S-TIM 3) are available for therapy. As they are manufactured by 80% from US plasma it was necessary to prove that they do not transmit HIV. For ethical reasons it is not possible to treat control groups of patients with non-virus- inactivated concentrate. Non-transmission of HIV can, therefore, only be proven if anti-HIV seroconversion does not occur in larger groups of patients treated with this type of product. We collected data from 60 patients, who were “virgin” (24) or, if pre-treated, anti-HIV seronegative. Therapy with Factor VIII TIM 3 or S-TIM 3 was started between Sept. 1984 and April 1986. The median length of observation till the last anti-HIV testing was 12 (6 - 24) months. The median total dosage of Factor VIII was 56,500 (500 - 427,500) IU, the median patient age was 20 (1 - 61) years. In none of the patients anti-HIV seroconversion (ELISA test) was observed. According to the rule ofthree the upper 95% confidence limit for random sample of 60 cases with zero events would be 3/60 or 5%.
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Schimpf, K. l., B. Kraus, W. Kreuz, H. H. Brackmann, F. Haschke, and W. Schramm. "NO ANTI-HIV SEROCONVERSION AFTER REPLACEMENT THERAPY WITH PASTEURIZED F VIII CONCENTRATE. A STUDY OF 151 PATIENTS WITH HEMOPHILIA A OR VON WILLEBRAND'S DISEASE." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643973.

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Transmission of hepatitis viruses and HIV has proven to be a risk of replacement therapy in hemophilia. As regards F VIII products a concentrate (Hemate HS or P) in which viruses are inactivated by heat-treatment over 10 hours at 60° C in aqueous solution is available since 1979. Our clinical studies have shown that this product does not transmit HBV and HNANBV. As the product was manufactured by 80% from US plasma it was necessary to prove that it also does not transmit HIV. As it is, for ethical reasons, not possible to treat a control group with non-virus-inactivated F VIII, non-transmission of HIV can only proven if anti-HIV seroconversion does not occur in larger groups of patients treated exclusively with this virus-inactivated product.We collected data from 151 patients treated with Hemate HS (P) who had never before received blood or blood products. Therapy was started between Feb. 1979 and Jan. 1986 (median July 7,1983). The median length of observation till the last anti-HIV testing was 24 (3 - 83) months. 112 patients were observed longer than 13 months. The median total dosage was 17,000 (500 -2,155,375) IU of F VIII, the median patient age was 6 (0,5 - 68) years. In none of these patients anti-HIV seroconversion (ELISA test) was observed. According to the rule of three, the upper 95% confidence limit for a random sample of 60 cases with zero events would be 3/60 or 5%. For greater numbers of n cases, as in our study, the range of confidence narrows increasingly. The period of observation of this study is hitherto the longest.
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Addiego, J. E., P. Bailey, M. Bradley, S. Courter, and M. Lee. "RECOVERY AND SURVIVAL STUDIES OF A NEW FACTOR VIII PRODUCT." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644052.

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Lyophilized protein concentrates are the international treatment of choice to manage bleeding in hemophiliacs. These pooled plasma products, however, expose the recipient of treatment to an increased risk of viral infections. While current manufacturing techniques of these products appear to be effective in eradicating the human immunodeficiency virus (HIV), transmission of other viruses, especially non-A/non-B (NANB) hepatitis, is still a majoor complication of concentrate therapy. Hyland Therapeutics Division Travenol Laboratories, Inc., has developed a new process using the techniques of immunoaffinity chromatography and organic solvent/detergent treatment to prepare a high specific activity product; Antihemophilic Factor (Human), Method M (AHF-M); that may render it free of pathogenic viruses. To determine the recovery and half-life of factor VIII in this product five severe hemophiliacs in a nonbleeding state were given! 50 U/kg of M-AHF and 50 U/kg of a currently licensed factor concentrate (HEMOFILe CT) in a crossover blinded study with a seven day interval between the respective infusions. The table below shows the recovery and half-life results for the five patients studiedThe factor VIII recoveries and half-lifes were similar for both products. No significant adverse clinical reactions were detected in any patient either during or after their infusions. This product appears to produce adequate circulating levels of factor VIII. It also appears to be safe for administration in humans. Further studies are on-going to test the overall efficacy of this product and to confirm that the manufacturing process is effective in eliminating pathogenic viruses
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Reports on the topic "Viruses transmission"

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Turell, M. J., C. N. Mores, J. S. Lee, J. J. Paragas, and D. Shermuhemedova. Experimental Transmission of Karshi and Langat (Tick-Borne Encephalitis Virus Complex) Viruses by Ornithodoros Ticks (Acari: Argasidae). Fort Belvoir, VA: Defense Technical Information Center, January 2004. http://dx.doi.org/10.21236/ada428609.

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Grumet, Rebecca, and Benjamin Raccah. Identification of Potyviral Domains Controlling Systemic Infection, Host Range and Aphid Transmission. United States Department of Agriculture, July 2000. http://dx.doi.org/10.32747/2000.7695842.bard.

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Potyviruses form one of the largest and most economically important groups of plant viruses. Individual potyviruses and their isolates vary in symptom expression, host range, and ability to overcome host resistance genes. Understanding factors influencing these biological characteristics is of agricultural importance for epidemiology and deployment of resistance strategies. Cucurbit crops are subject to severe losses by several potyviruses including the highly aggressive and variable zucchini yellow mosaic virus (ZYMV). In this project we sought to investigate protein domains in ZYMV that influence systemic infection and host range. Particular emphasis was on coat protein (CP), because of known functions in both cell to cell and long distance movement, and helper component-protease (HC-Pro), which has been implicated to play a role in symptom development and long distance movement. These two genes are also essential for aphid mediated transmission, and domains that influence disease development may also influence transmissibility. The objectives of the approved BARD project were to test roles of specific domains in the CP and HC-Pro by making sequence alterations or switches between different isolates and viruses, and testing for infectivity, host range, and aphid transmissibility. These objectives were largely achieved as described below. Finally, we also initiated new research to identify host factors interacting with potyviral proteins and demonstrated interaction between the ZYMV RNA dependent RNA polymerase and host poly-(A)-binding protein (Wang et al., in press). The focus of the CP studies (MSU) was to investigate the role of the highly variable amino terminus (NT) in host range determination and systemic infection. Hybrid ZYMV infectious clones were produced by substituting the CP-NT of ZYMV with either the CP-NT from watermelon mosaic virus (overlapping, but broader host range) or tobacco etch virus (TEV) (non- overlapping host range) (Grumet et al., 2000; Ullah ct al., in prep). Although both hybrid viruses initially established systemic infection, indicating that even the non-cucurbit adapted TEV CP-NT could facilitate long distance transport in cucurbits, after approximately 4-6, the plants inoculated with the TEV-CPNT hybrid exhibited a distinct recovery of reduced symptoms, virus titer, and virus specific protection against secondary infection. These results suggest that the plant recognizes the presence of the TEV CP-NT, which has not been adapted to infection of cucurbits, and initiates defense responses. The CP-NT also appears to play a role in naturally occurring resistance conferred by the zym locus in the cucumber line 'Dina-1'. Patterns of virus accumulation indicated that expression of resistance is developmentally controlled and is due to a block in virus movement. Switches between the core and NT domains of ZYMV-NAA (does not cause veinal chlorosis on 'Dina-1'), and ZYMV-Ct (causes veinal chlorosis), indicated that the resistance response likely involves interaction with the CP-NT (Ullah and Grumet, submitted). At the Volcani Center the main thrust was to identify domains in the HC-Pro that affect symptom expression or aphid transmissibility. From the data reported in the first and second year report and in the attached publications (Peng et al. 1998; Kadouri et al. 1998; Raccah et al. 2000: it was shown that: 1. The mutation from PTK to PAK resulted in milder symptoms of the virus on squash, 2. Two mutations, PAK and ATK, resulted in total loss of helper activity, 3. It was established for the first time that the PTK domain is involved in binding of the HC-Pro to the potyvirus particle, and 4. Some of these experiments required greater amount of HC-Pro, therefore a simpler and more efficient purification method was developed based on Ni2+ resin.
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Ullman, Diane, James Moyer, Benjamin Raccah, Abed Gera, Meir Klein, and Jacob Cohen. Tospoviruses Infecting Bulb Crops: Evolution, Diversity, Vector Specificity and Control. United States Department of Agriculture, September 2002. http://dx.doi.org/10.32747/2002.7695847.bard.

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Objectives. The overall goal of the proposed research was to develop a mechanistic understanding of tospovirus evolution, diversity and vector specificity that could be applied to development of novel methods for limiting virus establishment and spread. Our specific objectives were: 1) To characterize newly intercepted tospoviruses in onion, Hippeastrum and other bulb crops and compare them with the known tomato spotted wilt virus (TSWV) and its isolates; 2) To characterize intra- and interspecific variation in the virus transmission by thrips of the new and distinct tospoviruses. and, 3) To determine the basis of vector specificity using biological, cellular and molecular approaches. Background. New tospoviruses infecting bulb crops were detected in Israel and the US in the mid-90s. Their plant host ranges and relationships with thrips vectors showed they differed from the type member of the Tospovirus genus, tomato spotted wilt virus (TSWV). Outbreaks of these new viruses caused serious crop losses in both countries, and in agricultural and ornamental crops elsewhere. In the realm of plant infecting viruses, the tospoviruses (genus: Tospovirus , family: Bunyaviridae ) are among the most aggressive emerging viruses. Tospoviruses are transmitted by several species of thrips in a persistent, propagative fashion and the relationships between the viruses and their thrips vectors are often specific. With the emergence of new tospoviruses, new thrips vector/tospovirus relationships have also arisen and vector specificities have changed. There is known specificity between thrips vector species and particular tospoviruses, although the cellular and molecular bases for this specificity have been elusive. Major conclusions, solutions and achievements. We demonstrated that a new tospovirus, iris yellow spot virus (IYSV) caused "straw bleaching" in onion (Allium cepa) and lisianthus necrosis in lisianthus (Eustoma russellianum). Characterization of virus isolates revealed genetic diversity among US, Brazilian, Dutch and Israeli isolates. IYSV was not seed transmitted, and in Israel, was not located in bulbs of infected plants. In the US, infected plants were generated from infected bulbs. The relationship between IYSV and Thrips tabaci was shown to be specific. Frankliniella occidentalis, the primary vector of many other tospoviruses, did not transmit IYSV isolates in Israel or the US. Furthermore, 1': tabaci populations varied in their transmission ability. Transmission was correlated to IYSV presence in thrips salivary glands. In Israel, surveys in onion fields revealed that the onion thrips, Thrips tabaci Lindeman was the predominant species and that its incidence was strongly related to that of IYSV infection. In contrast, in the U.S., T. tabaci and F. occidentalis were present in high numbers during the times sampled. In Israel, insecticides reduced onion thrips population and caused a significant yield increase. In the US, a genetic marker system that differentiates non-thrips transmissible isolates from thrips transmissible isolate demonstrated the importance of the M RNA to thrips transmission of tospoviruses. In addition, a symbiotic Erwinia was discovered in thrips and was shown to cause significant artifacts in certain types of virus binding experiments. Implications, scientific and agricultural. Rapid emergence of distinct tospoviruses and new vector relationships is profoundly important to global agriculture. We advanced the understanding of IYSV in bulb crops and its relationships with thrips vector species. The knowledge gained provided growers with new strategies for control and new tools for studying the importance of particular viral proteins in thrips specificity and transmission efficiency.
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Pirone, Thomas P., Benjamin Raccah, and Nor Chejanovsky. Vector Specificity in Potyvirus Transmission: Role of the Helper Component. United States Department of Agriculture, January 2003. http://dx.doi.org/10.32747/2003.7586456.bard.

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Objectives: The overall objective of this research was to gain a better understanding of how potyviruses interact with their aphid vectors. The aim was to design new approaches for prevention of potyvirus spread by aphids. The sub-objectives included: (1). Determination of which of the HCs of different potyviruses effect efficient transmission by specific aphid vectors; (2). Determine regions in the HC that play a role in their compatibility with the vector; (3). Determine the factors within the aphid stylets that modify HC activity in transmission. Background of the topic: Background to the topic: Potyviruses are typical non persistent viruses. They are retained within the vector’s stylets and rapidly lost by the vector. Some potyviruses greatly differ in their ability to be transmitted by different aphid species. The present work centered on analyzing factors that may modify the interactions between the "helper component"(HC), the virions and the aphid species involved. Major conclusions, solutions and achievements: It was established that specificity of transmission may depend on aphid species used. It was also shown that specificity may depend on the affinity between HC and virion. However, the attempts to create activechimericTEV/TuMVHCs or ZYMV/TuMVHCs to identify the regions that determine interaction with a specific vector(s), were not successful. More progress was attained in objective 3: In Kentucky, tests were conducted to ascertain retention tobacco vein mottling virus (TVMV) HC in the stylets of L. erysimicompared to that in M. persicae. Ultra-thin section of stylets of aphids that fed on either TuMVHC or TVMVHC antibodies were treated with gold-labeled goat anti-rabbit antibodies.TuMV was seen in 25% the stylets of L. erysimi when they acquired TuMVHC but not when they acquired TVMVHC. In M. persicae, TVMVHC was present in 30% of the stylets. . Transmission with TuMVHC was not affected by treatment with L. erysimi saliva whereas transmission with PVYHC (which also is not functional in L. erysimi) was consistently reduced by about half. Saliva from M. persicaehad essentially no effect on either HC. The possible role aphid cuticle proteins (which are found on the stylets surface) in the association with the potyviralHC was investigated in Israel. This was done adopting two approaches: (a) isolation of cuticular proteins from aphid cuticle; (b) screening for genes encoding cuticular proteins. In the first approach, we succeeded in extracting proteins from whole homogenized M. persicaeusing concentrated urea. The extracted protein served for preparation of anti cuticular antibodies. In overlay experiments it was found that cuticular proteins specifically bind to ZYMVHC. In addition, a cDNA library of M. persicae has been prepared. Genes encoding for cuticular proteins were ascertained using antibodies to cuticular proteins. This allowed reporting the sequence of the first cuticular gene of aphids and comparing it in six aphid species. Implications, scientific and agricultural: Achievements: (1) Proofs were provided for the role of the specificity of the aphid species to the HC of certain potyviruses; (2) aphid’s saliva was found to affects transmission efficiency; (3) cuticle protein genes were isolated for the first time from aphid species and an association of cuticle protein with the potyviralHC was discerned. Agricultural and/or economic impact of the research findings: At this stage of research, our finding do not bear an agricultural or economic impact.
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Mawassi, Munir, Adib Rowhani, Deborah A. Golino, Avichai Perl, and Edna Tanne. Rugose Wood Disease of Grapevine, Etiology and Virus Resistance in Transgenic Vines. United States Department of Agriculture, November 2003. http://dx.doi.org/10.32747/2003.7586477.bard.

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Rugose wood is a complex disease of grapevines, which occurs in all growing areas. The disease is spread in the field by vector transmission (mealybugs). At least five elongated-phloem- limited viruses are implicated in the various rugose wood disorders. The most fully characterized of these are Grapevine virus A (GV A) and GVB, members of a newly established genus, the vitivirus. GVC, a putative vitivirus, is much less well characterized than GV A or GVB. The information regarding the role of GVC in the etiology and epidemiology of rugose wood is fragmentary and no sequence data for GVC are available. The proposed research is aimed to study the etiology and epidemiology of rugose wood disease, and to construct genetically engineered virus-resistant grapevines. The objectives of our proposed research were to construct transgenic plants with coat protein gene sequences designed to induce post-transcriptional gene silencing (pTGS); to study the epidemiology and etiology of rugose wood disease by cloning and sequencing of GVC; and surveying of rugose wood- associated viruses in Californian and Israeli vineyards. In an attempt to experimentally define the role of the various genes of GV A, we utilized the infectious clone, inserted mutations in every ORF, and studied the effect on viral replication, gene expression, symptoms and viral movement. We explored the production of viral RNAs in a GV A-infected Nicotiana benthamiana herbaceous host, and characterized one nested set of three 5'-terminal sgRNAs of 5.1, 5.5 and 6.0 kb, and another, of three 3'-terminal sgRNAs of 2.2, 1.8 and 1.0 kb that could serve for expression of ORFs 2-3, respectively. Several GV A constructs have been assembled into pCAMBIA 230 I, a binary vector which is used for Angrobacterium mediated transformation: GV A CP gene; two copies of the GV A CP gene arranged in the same antisense orientation; two copies of the GV A CP gene in which the downstream copy is in an antigens orientation; GV A replicase gene; GV A replicase gene plus the 3' UTR sequence; and the full genome of GV A. Experiments for transformation of N. benthamiana and grapevine cell suspension with these constructs have been initiated. Transgenic N. benthamiana plants that contained the CP gene, the replicase gene and the entire genome of GV A were obtained. For grapevine transformation, we have developed efficient protocols for transformation and successfully grapevine plantlets that contained the CP gene and the replicase genes of GV A were obtained. These plants are still under examination for expression of the trans genes. The construction of transgenic plants with GV A sequences will provide, in the long run, a means to control one of the most prevalent viruses associated with grapevines. Our many attempts to produce a cDNA library from the genome of GVC failed. For surveying of rugose wood associated viruses in California vineyards, samples were collected from different grape growing areas and tested by RT-PCR for GV A, GVB and GVD. The results indicated that some of the samples were infected with multiple viruses, but overall, we found higher incidence of GVB and GV A infection in California vineyards and new introduction varieties, respectively. In this research we also conducted studies to increase our understanding of virus - induced rootstock decline and its importance in vineyard productivity. Our results provided supporting evidence that the rootstock response to virus infection depends on the rootstock genotype and the virus type. In general, rootstocks are differ widely in virus susceptibility. Our data indicated that a virus type or its combination with other viruses was responsible in virus-induced rootstock decline. As the results showed, the growth of the rootstocks were severely affected when the combination of more than one virus was present.
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Dawson, William O., Moshe Bar-Joseph, Charles L. Niblett, Ron Gafny, Richard F. Lee, and Munir Mawassi. Citrus Tristeza Virus: Molecular Approaches to Cross Protection. United States Department of Agriculture, January 1994. http://dx.doi.org/10.32747/1994.7570551.bard.

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Citrus tristeza virus (CTV) has the largest genomes among RNA viruses of plants. The 19,296-nt CTV genome codes for eleven open reading frames (ORFs) and can produce at least 19 protein products ranging in size from 6 to 401 kDa. The complex biology of CTV results in an unusual composition of CTV-specific RNAs in infected plants which includes multiple defective RNAs and mixed infections. The complex structure of CTV populations poses special problems for diagnosis, strain differentiation, and studies of pathogenesis. A manipulatable genetic system with the full-length cDNA copy of the CTV genome has been created which allows direct studies of various aspects of the CTV biology and pathology. This genetic system is being used to identify determinants of the decline and stem-pitting disease syndromes, as well as determinants responsible for aphid transmission.
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Gottlieb, Yuval, Bradley Mullens, and Richard Stouthamer. investigation of the role of bacterial symbionts in regulating the biology and vector competence of Culicoides vectors of animal viruses. United States Department of Agriculture, June 2015. http://dx.doi.org/10.32747/2015.7699865.bard.

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Symbiotic bacteria have been shown to influence host reproduction and defense against biotic and abiotic stressors, and this relates to possible development of a symbiont-based control strategy. This project was based on the hypothesis that symbionts have a significant impact on Culicoides fitness and vector competence for animal viruses. The original objectives in our proposal were: 1. Molecular identification and localization of the newly-discovered symbiotic bacteria within C. imicola and C. schultzei in Israel and C. sonorensis in California. 2. Determination of the prevalence of symbiotic bacteria within different vector Culicoides populations. 3. Documentation of specific symbiont effects on vector reproduction and defense: 3a) test for cytoplasmic incompatibility in Cardinium-infected species; 3b) experimentally evaluate the role of the symbiont on infection or parasitism by key Culicoides natural enemies (iridescent virus and mermithid nematode). 4. Testing the role(s) of the symbionts in possible protection against infection of vector Culicoides by BTV. According to preliminary findings and difficulties in performing experimental procedures performed in other insect symbiosis systems where insect host cultures are easily maintained, we modified the last two objectives as follows: Obj. 3, we tested how symbionts affected general fitness of Israeli Culicoides species, and thoroughly described and evaluated the correlation between American Culicoides and their bacterial communities in the field. We also tried alternative methods to test symbiont-Culicoides interactions and launched studies to characterize low-temperature stress tolerances of the main US vector, which may be related to symbionts. Obj. 4, we tested the correlation between EHDV (instead of BTV) aquisition and Cardinium infection. Culicoides-bornearboviral diseases are emerging or re-emerging worldwide, causing direct and indirect economic losses as well as reduction in animal welfare. One novel strategy to reduce insects’ vectorial capacity is by manipulating specific symbionts to affect vector fitness or performance of the disease agent within. Little was known on the bacterial tenants occupying various Culicoides species, and thus, this project was initiated with the above aims. During this project, we were able to describe the symbiont Cardinium and whole bacterial communities in Israeli and American Culicoides species respectively. We showed that Cardinium infection prevalence is determined by land surface temperature, and this may be important to the larval stage. We also showed no patent significant effect of Cardinium on adult fitness parameters. We showed that the bacterial community in C. sonorensis varies significantly with the host’s developmental stage, but it varies little across multiple wastewater pond environments. This may indicate some specific biological interactions and allowed us to describe a “core microbiome” for C. sonorensis. The final set of analyses that include habitat sample is currently done, in order to separate the more intimately-associated bacteria from those inhabiting the gut contents or cuticle surface (which also could be important). We were also able to carefully study other biological aspects of Culicoides and were able to discriminate two species in C. schultzei group in Israel, and to investigate low temperature tolerances of C. sonorensis that may be related to symbionts. Scientific implications include the establishment of bacterial identification and interactions in Culicoides (our work is cited in other bacteria-Culicoides studies), the development molecular identification of C. schultzei group, and the detailed description of the microbiome of the immature and matched adult stages of C. sonorensis. Agricultural implications include understanding of intrinsic factors that govern Culicoides biology and population regulation, which may be relevant for vector control or reduction in pathogen transmission. Being able to precisely identify Culicoides species is central to understanding Culicoides borne disease epidemiology.
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Ullman, Diane E., Benjamin Raccah, John Sherwood, Meir Klein, Yehezkiel Antignus, and Abed Gera. Tomato Spotted Wilt Tosporvirus and its Thrips Vectors: Epidemiology, Insect/Virus Interactions and Control. United States Department of Agriculture, November 1999. http://dx.doi.org/10.32747/1999.7573062.bard.

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Objectives. The major aim of the proposed research was to study thrips-TSWV relationships and their role in the epidemiology of the virus with the aim of using this knowledge to reduce crop losses occurring due to epidemics. Our specific objectives were: To determine the major factors involved in virus outbreaks, including: a) identifying the thrips species involved in virus dissemination and their relative role in virus spread; b) determining the virus sources among wild and cultivated plants throughout the season and their role in virus spread, and, c) determining how temperature and molecular variations in isolates impact virus replication in plants and insects and impact the transmission cycle. Background to the topic. Tospoviruses are among the most important emerging plant viruses that impact production of agricultural and ornamental crops. Evolution of tospoviruses and their relationships with thrips vector species have been of great interest because of crop damage caused world wide and the complete absence of suitable methods of control. Tospoviruses threaten crops in Israel and the United States. By understanding the factors contributing to epidemics and the specific relationships between thrips species and particular tospoviruses we hope that new strategies for control can be developed that will benefit agriculture in both Israel and the United States. Major conclusions, solutions, achievements. We determined that at least three tospoviruses were involved in epidemics in Israel and the United States, tomato spotted wilt virus (TSWV), impatiens necrotic spot virus (INSV) and iris yellow spot virus (IYSV). We detected and characterized INSV for the first time in Israel and, through our efforts, IYSV was detected and characterized for the first time in both countries. We demonstrated that many thrips species were present in commercial production areas and trap color influenced thrips catch. Frankliniella occidentalis was the major vector species of INSV and TSWV and populations varied in transmission efficiency. Thrips tabaci is the sole known vector of IYSV and experiments in both countries indicated that F. occidentalis is not a vector of this new tospovirus. Alternate plant hosts were identified for each virus. A new monitoring system combining sticky cards and petunia indicator plants was developed to identify sources of infective thrips. This system has been highly successful in the U.S. and was used to demonstrate to growers that removal of plant sources of infective thrips has a dramatic impact on virus incidence. Finally, a putative thrips receptor mediating acquisition of TSWV was discovered. Implications, scientific and agricultural. Our findings have contributed to new control measures that will benefit agriculture. Identification of a putative thrips receptor for TSWV and our findings relative to thrips/tospovirus specificity have implications for development of innovative new control strategies.
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Ghanim, Murad, Joe Cicero, Judith K. Brown, and Henryk Czosnek. Dissection of Whitefly-geminivirus Interactions at the Transcriptomic, Proteomic and Cellular Levels. United States Department of Agriculture, February 2010. http://dx.doi.org/10.32747/2010.7592654.bard.

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Our project focuses on gene expression and proteomics of the whitefly Bemisia tabaci (Gennadius) species complex in relation to the internal anatomy and localization of expressed genes and virions in the whitefly vector, which poses a major constraint to vegetable and fiber production in Israel and the USA. While many biological parameters are known for begomovirus transmission, nothing is known about vector proteins involved in the specific interactions between begomoviruses and their whitefly vectors. Identifying such proteins is expected to lead to the design of novel control methods that interfere with whitefly-mediated begomovirus transmission. The project objectives were to: 1) Perform gene expression analyses using microarrays to study the response of whiteflies (B, Q and A biotypes) to the acquisition of begomoviruses (Tomato yellow leaf curl (TYLCV) and Squash leaf curl (SLCV). 2) Construct a whitefly proteome from whole whiteflies and dissected organs after begomovirus acquisition. 3) Validate gene expression by q-RTPCR and sub-cellular localization of candidate ESTs identified in microarray and proteomic analyses. 4) Verify functionality of candidate ESTs using an RNAi approach, and to link these datasets to overall functional whitefly anatomical studies. During the first and second years biological experiments with TYLCV and SLCV acquisition and transmission were completed to verify the suitable parameters for sample collection for microarray experiments. The parameters were generally found to be similar to previously published results by our groups and others. Samples from whole whiteflies and midguts of the B, A and Q biotypes that acquired TYLCV and SLCV were collected in both the US and Israel and hybridized to B. tabaci microarray. The data we analyzed, candidate genes that respond to both viruses in the three tested biotypes were identified and their expression that included quantitative real-time PCR and co-localization was verified for HSP70 by the Israeli group. In addition, experiments were undertaken to employ in situ hybridization to localize several candidate genes (in progress) using an oligonucleotide probe to the primary endosymbiont as a positive control. A proteome and corresponding transcriptome to enable more effective protein identification of adult whiteflies was constructed by the US group. Further validation of the transmission route of begomoviruses, mainly SLCV and the involvement of the digestive and salivary systems was investigated (Cicero and Brown). Due to time and budget constraints the RNAi-mediated silencing objective to verify gene function was not accomplished as anticipated. HSP70, a strong candidate protein that showed over-expression after TYLCV and SLCV acquisition and retention by B. tabaci, and co-localization with TYLCV in the midgut, was further studies. Besides this protein, our joint research resulted in the identification of many intriguing candidate genes and proteins that will be followed up by additional experiments during our future research. To identify these proteins it was necessary to increase the number and breadth of whitefly ESTs substantially and so whitefly cDNAs from various libraries made during the project were sequenced (Sanger, 454). As a result, the proteome annotation (ID) was far more successful than in the initial attempt to identify proteins using Uniprot or translated insect ESTs from public databases. The extent of homology shared by insects in different orders was surprisingly low, underscoring the imperative need for genome and transcriptome sequencing of homopteran insects. Having increased the number of EST from the original usable 5500 generated several years ago to >600,000 (this project+NCBI data mining), we have identified about one fifth of the whitefly proteome using these new resources. Also we have created a database that links all identified whitefly proteins to the PAVEdb-ESTs in the database, resulting in a useful dataset to which additional ESTS will be added. We are optimistic about the prospect of linking the proteome ID results to the transcriptome database to enable our own and other labs the opportunity to functionally annotate not only genes and proteins involved in our area of interest (whitefly mediated transmission) but for the plethora of other functionalities that will emerge from mining and functionally annotating other key genes and gene families in whitefly metabolism, development, among others. This joint grant has resulted in the identification of numerous candidate proteins involved in begomovirus transmission by B. tabaci. A next major step will be to capitalize on validated genes/proteins to develop approaches to interfere with the virus transmission.
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Ehrlich, Marcelo, John S. Parker, and Terence S. Dermody. Development of a Plasmid-Based Reverse Genetics System for the Bluetongue and Epizootic Hemorrhagic Disease Viruses to Allow a Comparative Characterization of the Function of the NS3 Viroporin in Viral Egress. United States Department of Agriculture, September 2013. http://dx.doi.org/10.32747/2013.7699840.bard.

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Project Title: "Development of a plasmid-based reverse genetics system for the Bluetongue and Epizootic Hemorrhagic Disease viruses to allow comparative characterization of the function of the NS3 viroporin in viral egress". Project details: No - IS-4192-09; Participants – Ehrlich M. (Tel Aviv University), Parker J.S. (Cornell University), DermodyT.S. (Vanderbilt University); Period - 2009-2013. Orbiviruses are insect-borne infectious agents of ruminants that cause diseases with considerable economical impact in Israel and the United States. The recent outbreaks of BTV in Europe and of Epizootic Hemorrhagic Disease Virus (EHDV) in Israel, underscore the need for: (i) a better comprehension of the infection process of orbiviruses, (ii) the identification of unique vs. common traits among different orbiviruses, (iii) the development of novel diagnosis and treatment techniques and approaches; all aimed at the achievement of more effective control and treatment measures. It is the context of these broad goals that the present project was carried out. To fulfill our long-term goal of identifying specific viral determinants of virulence, growth, and transmission of the orbiviruses, we proposed to: (i) develop reverse genetics systems for BTV and EHDV2-Ibaraki; and (ii) identify the molecular determinants of the NS3 nonstructural protein related to viroporin/viral egress activities. The first objective was pursued with a two-pronged approach: (i) development of a plasmid-based reverse genetics system for BTV-17, and (ii) development of an "in-vitro" transcription-based reverse genetics system for EHDV2-Ibaraki. Both approaches encountered technical problems that hampered their achievement. However, dissection of the possible causes of the failure to achieve viral spread of EHDV2-Ibaraki, following the transfection of in-vitro transcribed genomic segments of the virus, revealed a novel characteristic of EHDV2-Ibaraki infection: an uncharacteristically low fold increase in titer upon infection of different cell models. To address the function and regulation of NS3 we employed the following approaches: (i) development (together with Anima Cell Metrology) of a novel technique (based on the transfection of fluorescently-labeledtRNAs) that allows for the detection of the levels of synthesis of individual viral proteins (i.e. NS3) in single cells; (ii) development of a siRNA-mediated knockdown approach for the reduction in levels of expression of NS3 in EHDV2-Ibaraki infected cells; (iii) biochemical and microscopy-based analysis of the localization, levels and post-translational modifications of NS3 in infected cells. In addition, we identified the altered regulation and spatial compartmentalization of protein synthesis in cells infected with EHDV2-Ibaraki or the mammalian reovirus. In EHDV2-Ibaraki-infected cells such altered regulation in protein synthesis occurs in the context of a cell stress reponse that includes the induction of apoptosis, autophagy and activation of the stressrelated kinase c-Jun N-terminal Kinase (JNK). Interestingly, inhibition of such stress-related cellular processes diminishes the production of infectious virions, suggesting that EHDV usurps these responses for the benefit of efficient infection. Taken together, while the present project fell short of the generation of novel reverse genetics systems for orbiviruses, the development of novel experimental approaches and techniques, and their employment in the analysis of EHDV-infected cells, yielded novel insights in the interactions of orbiviruses with mammalian cells.
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