The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Anti Vasemagi - One of the best experts on this subject based on the ideXlab platform.
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association mapping reveals candidate loci for resistance and anaemic response to an emerging temperature driven Parasitic Disease in a wild salmonid fish
Molecular Ecology, 2018Co-Authors: Freed Ahmad, P V Debes, Gemma Palomar, Anti VasemagiAbstract:: Even though Parasitic infections are often costly or deadly for the host, we know very little which genes influence parasite susceptibility and Disease severity. Proliferative kidney Disease is an emerging and, at elevated water temperatures, potentially deadly Disease of salmonid fishes that is caused by the myxozoan parasite Tetracapsuloides bryosalmonae. By screening >7.6 K SNPs in 255 wild brown trout (Salmo trutta) and combining association mapping and Random Forest approaches, we identified several candidate genes for both the parasite resistance (inverse of relative parasite load; RPL) and the severe anaemic response to the parasite. The strongest RPL-associated SNP mapped to a noncoding region of the congeneric Atlantic salmon (S. salar) chromosome 10, whereas the second strongest RPL-associated SNP mapped to an intronic region of PRICKLE2 gene, which is a part of the planar cell polarity signalling pathway involved in kidney development. The top SNP associated with anaemia mapped to the intron of the putative PRKAG2 gene. The human ortholog of this gene has been associated with haematocrit and other blood-related traits, making it a prime candidate influencing parasite-triggered anaemia in brown trout. Our findings demonstrate the power of association mapping to pinpoint genomic regions and potential causative genes underlying climate change-driven Parasitic Disease resistance and severity. Furthermore, this work illustrates the first steps towards dissecting genotype-phenotype links in a wild fish population using closely related genome information.
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effect of environmental factors and an emerging Parasitic Disease on gut microbiome of wild salmonid fish
mSphere, 2017Co-Authors: Anti Vasemagi, Marko Visse, Veljo KisandAbstract:ABSTRACT The gastrointestinal tract (GIT) of fish supports a dynamic microbial ecosystem that is intimately linked to host nutrient acquisition, epithelial development, immune system priming, and Disease prevention, and we are far from understanding the complex interactions among parasites, symbiotic gut bacteria, and host fitness. Here, we analyzed the effects of environmental factors and Parasitic burdens on the microbial composition and diversity within the GIT of the brown trout ( Salmo trutta ). We focused on the emerging dangerous salmonid myxozoan parasite Tetracapsuloides bryosalmonae , which causes proliferative kidney Disease in salmonid fish, to demonstrate the potential role of GIT micobiomes in the modulation of host-parasite relationships. The microbial diversity in the GIT displayed clear clustering according to the river of origin, while considerable variation was also found among fish from the same river. Environmental variables such as oxygen concentration, water temperature, and river morphometry strongly associated with both the river microbial community and the GIT microbiome, supporting the role of the environment in microbial assemblage and the relative insignificance of the host genotype and gender. Contrary to expectations, the parasite load exhibited a significant positive relationship with the richness of the GIT microbiome. Many operational taxonomic units (OTUs; n = 202) are more abundant in T. bryosalmonae -infected fish, suggesting that brown trout with large parasite burdens are prone to lose their GIT microbiome homeostasis. The OTUs with the strongest increase in infected trout are mostly nonpathogenic aquatic, anaerobic sediment/sludge, or ruminant bacteria. Our results underscore the significance of the interactions among Parasitic Disease, abiotic factors, and the GIT microbiome in Disease etiology. IMPORTANCE Cohabiting microorganisms play diverse and important roles in the biology of multicellular hosts, but their diversity and interactions with abiotic and biotic factors remain largely unsurveyed. Nevertheless, it is becoming increasingly clear that many properties of host phenotypes reflect contributions from the associated microbiome. We focus on a question of how parasites, the host genetic background, and abiotic factors influence the microbiome in salmonid hosts by using a host-parasite model consisting of wild brown trout ( Salmo trutta ) and the myxozoan Tetracapsuloides bryosalmonae , which causes widely distributed proliferative kidney Disease. We show that parasite infection increases the frequency of bacteria from the surrounding river water community, reflecting impaired homeostasis in the fish gut. Our results also demonstrate the importance of abiotic environmental factors and host size in the assemblage of the gut microbiome of fish and the relative insignificance of the host genotype and gender.
Edmund Seto - One of the best experts on this subject based on the ideXlab platform.
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leveraging rural energy investment for Parasitic Disease control schistosome ova inactivation and energy co benefits of anaerobic digesters in rural china
PLOS ONE, 2009Co-Authors: Justin V Remais, Lin Chen, Edmund SetoAbstract:Cooking and heating remain the most energy intensive activities among the world's poor, and thus improved access to clean energies for these tasks has been highlighted as a key requirement of attaining the major objectives of the UN Millennium Development Goals. A move towards clean energy technologies such as biogas systems (which produce methane from human and animal waste) has the potential to provide immediate benefits for the control of neglected tropical Diseases. Here, an assessment of the Parasitic Disease and energy benefits of biogas systems in Sichuan Province, China, is presented, highlighting how the public health sector can leverage the proliferation of rural energy projects for infectious Disease control. Methodology/Findings: First, the effectiveness of biogas systems at inactivating and removing ova of the human parasite Schistosoma japonicum is experimentally evaluated. Second, the impact of biogas infrastructure on energy use and environmental quality as reported by surveyed village populations is assessed, as is the community acceptance of the technology. No viable eggs were recovered in the effluent collected weekly from biogas systems for two months following seeding with infected stool. Less than 1% of ova were recovered viable from a series of nylon bags seeded with ova, a 2-log removal attributable to biochemical inactivation. More than 90% of Ascaris lumbricoides ova (used as a proxy for S. japonicum ova) counted at the influent of two biogas systems were removed in the systems when adjusted for system residence time, an approximate 1-log removal attributable to sedimentation. Combined, these inactivation/removal processes underscore the promise of biogas infrastructure for reducing parasite contamination resulting from nightsoil use. When interviewed an average of 4 years after construction, villagers attributed large changes in fuel usage to the installation of biogas systems. Household coal usage decreased by 68%, wood by 74%, and crop waste by 6%. With reported energy savings valued at roughly 600 CNY per year, 2–3 years were required to recoup the capital costs of biogas systems. In villages without subsidies, no new biogas systems were implemented. Conclusions: Sustainable strategies that integrate rural energy needs and sanitation offer tremendous promise for long-term control of Parasitic Diseases, while simultaneously reducing energy costs and improving quality of life. Government policies can enhance the financial viability of such strategies by introducing fiscal incentives for joint sanitation/sustainable energy projects, along with their associated public outreach and education programs.
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environmental effects on Parasitic Disease transmission exemplified by schistosomiasis in western china
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Song Liang, Justin V Remais, Edmund Seto, Bo Zhong, Changhong Yang, Alan Hubbard, George M Davis, Xueguang Gu, Robert C SpearAbstract:Environmental effects on the transmission of many Parasitic Diseases are well recognized, but the role of specific factors like climate and agricultural practices in modulating transmission is seldom characterized quantitatively. Based on studies of Schistosoma japonicum transmission in irrigated agricultural environments in western China, a mathematical model was used to quantify environmental impacts on transmission intensity. The model was calibrated by using field data from intervention studies in three villages and simulated to predict the effects of alternative control options. Both the results of these interventions and earlier epidemiological findings confirm the central role of environmental factors, particularly those relating to snail habitat and agricultural and sanitation practices. Moreover, the findings indicate the inadequacy of current niclosamide-praziquantel strategies alone to achieve sustainable interruption of transmission in some endemic areas. More generally, the analysis suggests a village-specific index of transmission potential and how this potential is modulated by time-varying factors, including climatological variables, seasonal water-contact patterns, and irrigation practices. These time-variable factors, a village's internal potential, and its connectedness to its neighbors provide a framework for evaluating the likelihood of sustained schistosomiasis transmission and suggest an approach to quantifying the role of environmental factors for other Parasitic Diseases.
R B Besier - One of the best experts on this subject based on the ideXlab platform.
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veterinary parasitology in australia a short history
Veterinary Parasitology, 2013Co-Authors: Ian Beveridge, R B BesierAbstract:Abstract As an important producer and exporter of livestock products, animal health has always been of major significance to the Australian economy, and research into efficient parasite control has continued since the 1800s. With substantial research achievements also involving parasites of companion animals and wildlife, Australian parasitologists have made numerous contributions of global significance. This summary outlines the development of investigations into parasite biology and Parasitic Disease in Australia.
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Veterinary parasitology in Australia – A short history
Veterinary Parasitology, 2013Co-Authors: Ian Beveridge, R B BesierAbstract:Abstract As an important producer and exporter of livestock products, animal health has always been of major significance to the Australian economy, and research into efficient parasite control has continued since the 1800s. With substantial research achievements also involving parasites of companion animals and wildlife, Australian parasitologists have made numerous contributions of global significance. This summary outlines the development of investigations into parasite biology and Parasitic Disease in Australia.
Max Murray - One of the best experts on this subject based on the ideXlab platform.
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genetic resistance to Parasitic Disease particularly of resistance in ruminants to gastrointestinal nematodes
Veterinary Parasitology, 1994Co-Authors: M J Stear, Max MurrayAbstract:There is substantial variation among individuals in susceptibility to a wide variety of Parasitic Diseases and part of this variation in susceptibility is due to genetic factors. The challenge now is to determine the best methods of using the variation to improve our understanding of Parasitic infection and to reduce the ravages of Parasitic Disease. Scientific and commercial applications will depend upon the type of genetic variation. Variation among breeds can be easily exploited by a policy of breed substitution. Variation within a breed can be exploited by selective breeding to improve resistance to infection or to Disease, but more work is needed to develop selection indices which are acceptable to livestock breeders. Identifying genes which contribute to the variation in resistance provides a better understanding of the mechanisms of resistance but more work is needed to determine if such genes, alone or in combination, account for a sufficient proportion of the variation in resistance to allow marker assisted selection. A comparison of responses in susceptible and resistant stock provides a powerful tool to distinguish among protective, irrelevant and pathological responses. These themes have been illustrated by three studies of gastrointestinal nematode infections in ruminants.
Brian G Williams - One of the best experts on this subject based on the ideXlab platform.
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malnutrition age and the risk of Parasitic Disease visceral leishmaniasis revisited
Proceedings of The Royal Society B: Biological Sciences, 1993Co-Authors: Brian G WilliamsAbstract:Children are said to be at greater risk of developing visceral leishmaniasis (VL) when they are younger and more malnourished. If malnutrition really is associated with VL, this potentially fatal and visible Disease may be a general indicator of community health among the rural and suburban poor. Previous conclusions reached about the roles of malnutrition and age in VL epidemiology are questionable because they may have been confounded by transmission rate, because they have not been able to distinguish between different mechanisms of acquiring immunity, and because empirical observations have not been compared with theoretical expectations. Here we offer a framework with which to investigate these questions quantitatively, and do so with published data from endemic areas of Brazil. We conclude that children are indeed more susceptible to VL when they are younger and more malnourished, but it remains unclear whether the immunity to VL acquired with age is always acquired as a result of infection. The significance for leishmaniasis control, and for the control of other Diseases associated with malnutrition, will depend on underlying mechanisms, which are not yet understood.
