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We propose to dissect the genetics of anthelminthic resistance in Haemonchus contortus, a sheep parasitic nematode, exploiting high-throuput sequencing technology. The first goal is to to mine the levamisole resistance trait in H.contortus in a selected introgression line. The second goal will be to sequence isolates from populations in regions known to be under high and low levels of anthelminthic selection pressure. Results obtained from the two approaches will allow us to understand to what extent anthelminthic use has shaped the genetic structure of H.contortus populations and will provide new insights into the diversity and evolution of H.contortus.
As a research engineer at INRA since 2012, I am involved in two research strands in the “war against worms”, i.e. the development of integrated strategies for field application in horses and small ruminants, and the mining of parasitic nematodes genomes to unravel novel targets. The purpose of my two successive fellowships in AgreenSkills and AgreenSkills+, was to mine the genomes and transcriptomes of Haemonchus contortus, the most pathogenic sheep parasitic nematode, to characterize its adaptation to the main environmental constraints, i.e. the host, anthelmintics and climate. The sequencing of 265 individual males unraveled how human history shaped their population structure, and the genomic footprints left by exposure to anthelmintics and adaptation to climatic conditions. We also sequenced an introgression line to build a comprehensive picture of the genetic architecture of levamisole resistance. Our latest results dedicated to the understanding of the nematode adaptation to its host, revealed minor changes in the face of sheep with contrasted genetic background. Publication of these results is currently on-going. Meanwhile, I recently received a grant to initiate the building of horse parasitic nematode genomes and to study pyrantel resistance in these species when I move back to my INRA lab. In the frame of a joint collaboration with INRA scientist, I will also take part in the study of the interplay between Cryptosporidium parvum infection and the gut microbiota.
A Clark, G. Sallé, V Ballan, F Reigner, A Meynadier, J Cortet, C Koch, M Riou, A Blanchard, N Mach, 2018. Strongyle infection and gut microbiota: profiling of resistant and susceptible horses over a grazing season. Frontiers in Physiology 9, 272. Doi: 10.3389/fphys.2018.00272.
Sallé G, Laing R, Cotton JA, Maitland K, Martinelli A, Holroyd N, Tracey A, Berriman M, Smith WD, Newlands GFJ, Hanks E, Devaney E, Britton C. Transcriptomic profiling of nematode parasites surviving vaccine exposure. Int J Parasitol. 2018 Mar 10. Doi: 10.1016/j.ijpara.2018.01.004.
Mach N, Foury A, Kittelmann S, Reigner F, Moroldo M, Ballester M, Esquerré D, Rivière J, Sallé G, Gérard P, Moisan M-P and Lansade L, 2017. The Effects of Weaning Methods on Gut Microbiota Composition and Horse Physiology. Frontiers in Physiology. 8:535. Doi: 10.3389/ fphys.2017.00535.
Sallé G, Cortet J, Bois I, Dubès C, Guyot-Sionest Q, Larrieu C, Landrin V, Majorel G, Wittreck S, Woringer E, Couroucé A, Guillot J, Jacquiet P, Guégnard F, Blanchard A, Leblond A., 2017. Risk factor analysis of equine strongyle resistance to anthelmintics. Int J Parasitol Drugs Drug Resist. 7(3):407415.
Sallé G, Cortet J, Koch C, Gascogne T, Reigner F, Cabaret J., 2016. Ivermectin failure in the control of Oxyuris equi in a herd of ponies in France. Vet. Parasitol. 229:73-75.
Léopold Escande prize for PhD work, Toulouse University (2013)