1 Emergence and clonal expansion of Vibrio aestuarianus 1 lineages pathogenic for oysters in Europe. 2 Aurélie Mesnil 1,2 , Maude Jacquot 1 , Céline Garcia 1 , Delphine Tourbiez 1 , Lydie Canier 1 , Audrey 3 Bidois 2 , Lionel Dégremont 1 , Deborah Cheslett 3 , Michelle Geary 3 , Alessia Vetri 4 , Ana Roque 5 , 4 Dolors Furones 5 , Alison Garden 6 , Petya Orozova 7 , Isabelle Arzul 1 , Mathieu Sicard 8 , Guillaume 5 Charrière 2 , Delphine Destoumieux-Garzón 2 , Marie-Agnès Travers 2* 6 7 1 ASIM, Ifremer, Station de La Tremblade, avenue de Mus du Loup, 17390 La Tremblade, 8 France 9 2 IHPE, Université de Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, 10 Montpellier, France 11 3 Marine Institute MI, Rinville, Oranmore, Co. Galway, H91 R673, Ireland 12 4 Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 13 Legnaro (PD), Italy 14 5 IRTA La Ràpita. Aquaculture Program. 43540 – San Carles de la Ràpita, Spain. 15 6 Marine Laboratory, Marine Scotland Science, Aberdeen, UK. 16 7 National Diagnostic and Research Veterinary Medical Institute, Sofia, Bulgaria. 17 8 ISEM, Université de Montpellier, CNRS, IRD, Montpellier, France. 18 19 * Corresponding author: marie.agnes.travers@ifremer.fr 20 21 Competing interests: The authors declare no conflict of interest. 22 (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. The copyright holder for this preprint this version posted August 13, 2022. ; https://doi.org/10.1101/2022.04.04.486953 doi: bioRxiv preprint