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Browsing by Author "Xie, Yue"

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    International meeting on sarcoptic mange in wildlife, June 2018, Blacksburg, Virginia, USA
    Astorga, Francisca; Carver, Scott; Almberg, Emily S.; Sousa, Giovane R.; Wingfield, Kimberly; Niedringhaus, Kevin D.; Van Wick, Peach; Rossi, Luca; Xie, Yue; Cross, Paul C.; Angelone, Samer; Gortázar, Christian; Escobar, Luis E. (BMC, 2018-08-03)
    Sarcoptic mange is a globally distributed disease caused by the burrowing mite Sarcoptes scabiei, which also causes scabies in humans. A wide and increasing number of wild mammal species are reported to be susceptible to mange; however, the impacts of the disease in wildlife populations, mechanisms involved in its eco-epidemiological dynamics, and risks to public and ecosystem health are still unclear. Major gaps exist concerning S. scabiei host specificity and the mechanisms involved in the different presentations of the disease, which change between individuals and species. Immunological responses to the mite may have a relevant role explaining these different susceptibilities, as these affect the clinical signs, and consequently, the severity of the disease. Recently, some studies have suggested sarcoptic mange as an emerging threat for wildlife, based on several outbreaks with increased severity, geographical expansions, and novel wild hosts affected. Disease ecology experts convened for the “International Meeting on Sarcoptic Mange in Wildlife” on 4–5 June 2018, hosted by the Department of Fish and Wildlife Conservation at Virginia Tech in Blacksburg, Virginia, USA. The meeting had a structure of (i) pre-workshop review; (ii) presentation and discussions; and (iii) identification of priority research questions to understand sarcoptic mange in wildlife. The workgroup concluded that research priorities should be on determining the variation in modes of transmission for S. scabiei in wildlife, factors associated with the variation of disease severity among species, and long-terms effects of the mange in wildlife populations. In this note we summarize the main discussions and research gaps identified by the experts.
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    A new paraprobiotic-based treatment for control of Haemonchus contortus in sheep
    Sanders, John; Xie, Yue; Gazzola, David; Li, Hanchen; Abraham, Ambily; Flanagan, Kelly; Rus, Florentina; Miller, Melanie; Hu, Yan; Guynn, Sierra; Draper, Austin; Vakalapudi, Sridhar; Petersson, Katherine H.; Zarlenga, Dante; Li, Robert W.; Urban, Joseph F., Jr.; Ostroff, Gary R.; Zajac, Anne M.; Aroian, Raffi, V (2020-12)
    Haemonchus contortus is a critical parasite of goats and sheep. Infection by this blood-feeding gastrointestinal nematode (GIN) parasite has significant health consequences, especially in lambs and kids. The parasite has developed resistance to virtually all known classes of small molecule anthelmintics used to treat it, giving rise in some areas to multidrug resistant parasites that are very difficult to control. Thus, new anthelmintics are urgently needed. Bacillus thuringiensis (Bt) crystal protein 5B (Cry5B), a naturally occurring protein made by a bacterium widely and safely used around the world as a bioinsecticide, represents a new non-small molecule modality for treating GINs. Cry5B has demonstrated anthelmintic activities against parasites of monogastric animals, including some related to those that infect humans, but has not yet been studied in a ruminant. Here we show that H. contortus adults are susceptible to Cry5B protein in vitro. Cry5B produced in its natural form as a sporecrystal lysate against H. contortus infections in goats had no significant efficacy. However, a new Active Pharmaceutical Ingredient (API) paraprobiotic form of Cry5B called IBaCC (Inactivated Bacterium with Cytosolic Crystals), in which Cry5B crystals are encapsulated in dead Bt cell wall ghosts, showed excellent efficacy in vitro against larval stages of H. contortus and relative protein stability in bovine rumen fluid. When given to sheep experimentally infected with H. contortus as three 60 mg/kg doses, Cry5B IBaCC resulted in significant reductions in fecal egg counts (90%) and parasite burdens (72%), with a very high impact on female parasites (96% reduction). These data indicate that Cry5B IBaCC is a potent new treatment tool for small ruminants in the battle against H. contortus.
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    Sarcoptic mange: An emerging panzootic in wildlife
    Escobar, Luis E.; Carver, Scott; Cross, Paul C.; Rossi, Luca; Almberg, Emily S.; Yabsley, Michael J.; Niedringhaus, Kevin D.; Van Wick, Peach; Dominguez-Villegas, Ernesto; Gakuya, Francis; Xie, Yue; Angelone, Samer; Gortázar, Christian; Astorga, Francisca (2021-03-23)
    Sarcoptic mange, a skin infestation caused by the mite Sarcoptes scabiei, is an emerging disease for some species of wildlife, potentially jeopardizing their welfare and conservation. Sarcoptes scabiei has a near-global distribution facilitated by its forms of transmission and use of a large diversity of host species (many of those with broad geographic distribution). In this review, we synthesize the current knowledge concerning the geographic and host taxonomic distribution of mange in wildlife, the epidemiological connections between species, and the potential threat of sarcoptic mange for wildlife conservation. Recent sarcoptic mange outbreaks in wildlife appear to demonstrate ongoing geographic spread, increase in the number of hosts and increased virulence. Sarcoptic mange has been reported in at least 12 orders, 39 families and 148 species of domestic and wild mammals, making it one of the most generalist ectoparasites of mammals. Taxonomically, the orders with most species found infested so far include Perissodactyla (67% species from the entire order), Artiodactyla (47%), and Diprotodontia (67% from this order). This suggests that new species from these mammal orders are likely to suffer cross-species transmission and be reported positive to sarcoptic mange as surveillance improves. We propose a new agenda for the study of sarcoptic mange in wildlife, including the study of the global phylogeography of S. scabiei, linkages between ecological host traits and sarcoptic mange susceptibility, immunology of individuals and species, development of control strategies in wildlife outbreaks and the effects of global environmental change in the sarcoptic mange system. The ongoing transmission globally and sustained spread among areas and wildlife species make sarcoptic mange an emerging panzootic in wildlife. A better understanding of sarcoptic mange could illuminate the aspects of ecological and evolutionary drivers in cross-species transmission for many emerging diseases.