title: Genetic evolution of equine influenza virus strains (H3N8) isolated in France from 1967 to 2015 and the implications of several potential pathogenic factors.
abstract: Equine influenza virus (EIV) is a major respiratory pathogen of horses despite the availability of equine influenza vaccines. This study aimed to determine genetic evolution of EIV strains in France between 1967 to present. A whole genome comparative analysis was also conducted on recent French strains in order to identify potential factors of pathogenicity. Comparison of French EIV sequences with vaccine and worldwide epidemic strains revealed amino acid substitutions in both haemagglutinin (HA) and neuraminidase, especially within the antigenic sites and/or close to receptor binding sites (HA). Amino acid substitutions were also identified in other genes, mainly the polymerase complex proteins and PB1-F2. Viruses belonging to Eurasian and American lineages have circulated until 2003 and Florida sub-lineage Clade 2 strains predominates since 2005. The last French strain (2015) displayed several specificities in HA suggesting the occurrence of antigenic drift with presence of pathogenic markers in the PA and PB1-F2 genes.
authors.affiliation: LABÉO-Frank Duncombe, 1 Route de Rosel, 14053 Caen Cedex 4, France; University of Caen Basse-Normandie, 14000 Caen, France; Unité de Recherche Risques Microbiens (U2RM), EA 4655, and Chair of Excellence, Equine Immunology, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France. Electronic address: stephanie.fougerolle@laboratoire-labeo.fr.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Fougerolle
authors.affiliation: LABÉO-Frank Duncombe, 1 Route de Rosel, 14053 Caen Cedex 4, France; University of Caen Basse-Normandie, 14000 Caen, France; Unité de Recherche Risques Microbiens (U2RM), EA 4655, and Chair of Excellence, Equine Immunology, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Legrand
authors.affiliation: Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France; ANSES-Dozulé Laboratory for Equine Diseases, Virology Unit, Goustranville, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Lecouturier
authors.affiliation: Université Paris-Est, Anses Maisons-Alfort Laboratory for Animal Health, UMR1161 Virologie, Maisons-Alfort, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Sailleau
authors.affiliation: University of Caen Basse-Normandie, 14000 Caen, France; Unité de Recherche Risques Microbiens (U2RM), EA 4655, and Chair of Excellence, Equine Immunology, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France; Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Kentford, CB8 7UU Newmarket, United Kingdom.
authors.forename: Romain
authors.initials: R
authors.lastname: Paillot
authors.affiliation: Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France; ANSES-Dozulé Laboratory for Equine Diseases, Virology Unit, Goustranville, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Hans
authors.affiliation: LABÉO-Frank Duncombe, 1 Route de Rosel, 14053 Caen Cedex 4, France; University of Caen Basse-Normandie, 14000 Caen, France; Unité de Recherche Risques Microbiens (U2RM), EA 4655, and Chair of Excellence, Equine Immunology, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 Avenue du Maréchal Montgomery, 14000 Caen, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pronost
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D019143:Evolution, Molecular; D005602:France / Q000453:epidemiology; D016678:Genome / Q000235:genetics; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D006734:Horse Diseases / Q000453:epidemiology / Q000821:virology*; D006736:Horses / Q000821:virology*; D053123:Influenza A Virus, H3N8 Subtype / Q000235:genetics* / Q000302:isolation & purification; D009439:Neuraminidase / Q000235:genetics*; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D016415:Sequence Alignment
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D009439:Neuraminidase
keywords: Antigenic drift; Equine influenza; Horse; Pathogenicity markers; Surveillance