Chastagner A. 1, Dugat T. 2 , Vourc’h G. 1, Verheyden H. 3, Legrand L. 4, Bachy V. 5, Chabanne L. 6, Joncour G. 7, Maillard R. 8, Haddad N. 2, Boulouis H.-J.2, Bailly X. 1 & Leblond A. 9 1 : INRA, UR346 Epidémiologie Animale, F-63122 Saint Genès Champanelle, France ; 2: Université Paris-Est, Ecole Nat. Vét. d’Alfort, UMR BIPAR ENVA Anses UPEC USC INRA, 94706 Maisons-Alfort, France ; 3 : INRA, CEFS, F-31326 CASTANET TOLOSAN, France ; 4 : Frank Duncombe Lab.; 14053 Caen Cedex 4, France; EA 4655 U2RM – University of Caen Basse-Normandy, 14000 Caen, France ; 5 : Lab. Vet. Dept.du Rhône, Campus VetAgro Sup, 69280 Marcy l’Etoile , France ; 6 : Université de Lyon, VetAgro Sup, F-69280 Marcy l’Etoile, France ; 7 : Groupe Vétérinaire de Callac, 22160 Callac , France ; 8: Ecole Nat. Vet.de Toulouse, Unité pathologie des ruminants UMR BIPAR 31076 Toulouse , France ; 9 : INRA UR346 Epidémiologie Animale,et Département Hippique, VetAgroSup, F-69280 Marcy L’Etoile, France Context : Anaplasma phagocytophilum is a tick-borne bacterium, responsible of the granulocytic anaplasmosis in mammals, which causes important economic losses in cattle and sheep herds in Europe. A better knowledge of the genetic diversity of A. phagocytophilum is necessary: to understand the bacterial transmission cycle and to implement prevention and control plan. Study objective:: To characterize the genetic diversity of A. phagocytophilum that circulate in ill cattle in France in order to identify host species that participate in the same epidemiological cycle and might be potential reservoir hosts. 1. Samples 104 cattle, 11 horses, 3 dogs 40 roe deer 2. Extraction to DNA sequences France (coll.: LABÉO – Frank Duncombe , LDA 22, LVD 69, VetAgro Sup et SNGTV) DNA extraction in column from blood or spleen Detection by qPCR Amplification of 8 loci by nested PCR Preliminary amplification by WGA Bretagne & Franche Comté (local hunt plan) Vallons de Gascogne & Gardouch (coll. INRA Toulouse) (b) (a) SANGER sequencing Results: Three groups of A. phagocytophilum genotypes were identified. No geographic structure was observed in genotype distribution. • cluster 1: cattle & roe deer => hypothesis: spill-over of strains from roe deer to cattle because this genotype was rare in cattle (<2%) • cluster 2: cattle only • cluster 3: cattle, horses, dogs and American reference strains Fig. (b): Geographic localization of genotypes identified in the Supertree. => Reservoir hosts not identified for clusters 2 & 3 Fig. (a): “SuperTree” built from DNA sequences of 8 loci of A. phagocytophilum (msp4, groESL, typA, pleD, gyrA, recG, polA and one intergenic region) with Mr Bayes. Discussion & perspectives: The three groups of A. phagocytophilum co-existing in cattle from France could by linked with: - a difference of cycle with different reservoir hosts (like rodents, hedgehogs, hares …) - a difference of clinical symptoms or virulence Further studies about the genetic diversity of A.phagocytophilum in a restricted area will be necessary to understand the contribution of both domestic animals and potential reservoir hosts to the spread of the bacterium. Financeurs :
© Copyright 2024