Genetic evolution of equine influenza virus strains (H3N8) isolated in France from 1967 to 2015 and the implications of several potential pathogenic factors

International audienceEquine 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

Molecular analysis of two local falciparum malaria outbreaks on the French Guiana coast confirms the msp1 B-K1/varD genotype association with severe malaria

BACKGROUND: Plasmodium falciparum outbreaks can occur in the coastal area of French Guiana, where the population is essentially non-immune. Two sporadic outbreaks were observed, including one with severe malaria cases. To characterize these outbreaks and verify previous observations of specific genotype characteristics in severe malaria in this area, all cases from each outbreak were studied. METHODS: P. falciparum genotypes for six genetic loci were determined by PCR amplification from peripheral blood parasites. The msp1/block2 and msp2 genotypes were determined by DNA sequencing. Microsatellite and varD genotyping was based on size polymorphism and locus-specific amplification. RESULTS: The outbreak including severe malaria cases was associated with a single genotype. The other mild malaria outbreak was due to at least five distinct genotypes. CONCLUSION: Two distinct types of outbreak occured despite systematic and sustained deployement of malaria control measures, indicating a need for reinforced vigilance. The varD/B-K1 msp1 linkage and its association with severe malaria in this area was confirmed

Equine herpesvirus diseases: relevance and limits of molecular tools

At least five equine herpesviruses are known to infect horses: three alpha herpesviruses (equine herpesvirus- 1, -3 and -4) and two gamma herpesviruses (equine herpesvirus-2 and -5). Equine herpesvirus- 1 is responsible for three clinical presentations: respiratory, abortigenic and neurological. This latter, widely known as EHV-1 associated, myeloencephalopathy has been thoroughly investigated over the past years. Most of the studies focused on the relation between the presence of a mutation in ORF 30 coding for DNA polymerase and the expression of the paralytic (neurological) form. Even if this mutation seems to play a role, other factors related to the host and the environment are certainly involved in the development of the disease. Equine herpesvirus-4 is better known as the rhinopneumonia virus and is responsible for a large part of respiratory disorders in young foals. Equine herpesvirus- 3 is responsible for equine coital exanthema, whose transmission through the respiratory tract is now proven. Equine herpesvirus-2 and -5 are associated with subclinical respiratory diseases in equine athletes, even though their pathogenic role has yet to be clarified as they were detected in all continents only relatively recently. The development of molecular genetic tools lead to major progress in the detection of these viruses, but the differentiation between latent and infectious forms is still unresolved. Although studies are currently performed on the typing of strains responsible for different clinical presentations involving equine herpesviruses as well as in other equine viruses (influenza, equine viral arteritis), there is no international consensus on a phylogenic tree for any of the 5 equine herpesviruses. Further studies are definitely required to monitor and characterise the different strains of EHV.Au moins cinq herpèsvirus équins peuvent infecter le cheval: trois alpha-herpèsvirus (les herpèsvirus 1, 3 et 4) et deux gamma-herpèsvirus (les herpèsvirus équins 2 et 5). L'herpèsvirus équin 1 est responsable de trois formes cliniques: une forme respiratoire, une forme abortive et une forme neurologique. Cette dernière, plus connue sous le nom de myéloencéphalopathie à HVE-1, a fait l'objet de nombreuses études ces dernières années. La plupart des travaux ont porté sur la relation entre la présence d'une mutation dans l'ORF 30 codant l'ADN polymérase et l'expression de la forme paralytique. Si cette mutation semble jouer un rôle, d'autres facteurs liés à l'hôte et à l'environnement participent certainement au développement de la maladie. L'herpèsvirus équin 4 est plus connu sous le nom de virus de la rhinopneumonie et est responsable d'une part importante des affections respiratoires chez les jeunes poulains. L'herpèsvirus équin 3 est responsable de l'exanthème coïtal équin et l'on sait aujourd'hui qu'il peut se transmettre par les voies respiratoires. Les herpèsvirus équins 2 et 5 sont associés aux maladies respiratoires subcliniques du cheval athlète même si leur rôle reste à préciser, leur découverte sur l'ensemble des continents étant relativement récente. Le développement des outils de génétique moléculaire a permis de faire des progrès importants dans la détection de ces virus même si un challenge demeure: différencier les formes latentes des formes infectieuses. Si comme pour d'autres virus équins (ex: grippe, artérite virale équine), des travaux sont réalisés pour typer les différentes souches responsables de différentes formes d'expression de la maladie, il n'existe toujours pas de consensus international sur un arbre phylogénique pour aucun de ces cinq herpèsvirus équins. Le suivi et la caractérisation des différentes souches d'HVEs sont très certainement l'autre défi de demain

Emergence of novel equine arteritis virus (EAV) variants during persistent infection in the stallion: Origin of the 2007 French EAV outbreak was linked to an EAV strain present in the semen of a persistently infected carrier stallion

AbstractDuring the summer of 2007, an outbreak of equine viral arteritis (EVA) occurred in Normandy (France). After investigation, a link was suggested between an EAV carrier stallion (A) and the index premise of the outbreak. The full-length nucleotide sequence analysis of a study reference strain (F27) isolated from the lung of a foal revealed a 12,710 nucleotides EAV genome with unique molecular hallmarks in the 5′UTR leader sequence and the ORF1a sequence encoding the non-structural protein 2. The evolution of the viral population in the persistently infected Stallion A was then studied by cloning ORFs 3 and 5 of the EAV genome from four sequential semen samples which were collected between 2000 and 2007. Molecular analysis of the clones confirmed the likely implication of Stallion A in the origin of this outbreak through the yearly emergence of new variants genetically similar to the F27 strain

Bovine neosporosis: from life cycle to prophylaxis

Neospora caninum is an apicomplexan parasite, identified about twenty years ago. Although it can cause neurological symptoms in newborn cattle, its main economic and health repercussion in breeding is due to abortions. The life cycle of N. caninum is not yet fully understood. Its currently identified final hosts are dogs and coyotes, but foxes are also strongly suspected. To be effective, treatment and prophylaxis must be based on sound knowledge of the life cycle and pathophysiology of this protozoosis. There is no treatment currently available. Many vaccine studies are being performed using various strategies, but only disease control methods are possible for the moment, alongside the crucial advisory role of veterinary practitioners.Le parasite N. caninum est un protozoaires identifié il y a une vingtaine d'années.Bien que l'infection par Neospora caninum puisse se manifester par des symptômes neurologiques en pathologie bovine néonatale, sa principale répercussion économique et sanitaire en élevage est due aux avortements. Son cycle parasitaire est encore imparfaitement connu. Ses hôtes définitifs actuellement identifiés avec certitude sont le chien, le coyote et le dingo, mais le renard est aussi fortement suspecté. Une bonne connaissance du cycle évolutif du parasite et de la physiopathologie de la néosporose est indispensable pour définir des méthodes de lutte efficaces. À ce jour, il n'existe pas de traitement. De nombreux essais vaccinaux sont réalisés avec différentes stratégies. Seules des méthodes de lutte sanitaire sont envisageables avec un rôle essentiel de conseil pour le vétérinaire sanitaire

Effect of a Dual Task on Postural Control in Dyslexic Children

Several studies have examined postural control in dyslexic children; however, their results were inconclusive. This study investigated the effect of a dual task on postural stability in dyslexic children. Eighteen dyslexic children (mean age 10.3±1.2 years) were compared with eighteen non-dyslexic children of similar age. Postural stability was recorded with a platform (TechnoConcept®) while the child, in separate sessions, made reflex horizontal and vertical saccades of 10° of amplitude, and read a text silently. We measured the surface and the mean speed of the center of pressure (CoP). Reading performance was assessed by counting the number of words read during postural measures. Both groups of children were more stable while performing saccades than while reading a text. Furthermore, dyslexic children were significantly more unstable than non-dyslexic children, especially during the reading task. Finally, the number of words read by dyslexic children was significantly lower than that of non-dyslexic children and, in contrast to the non-dyslexic children. In line with the U-shaped non-linear interaction model, we suggest that the attention consumed by the reading task could be responsible for the loss of postural control in both groups of children. The postural instability observed in dyslexic children supports the hypothesis that such children have a lack of integration of multiple sensorimotor inputs

Transposable Elements Are a Major Cause of Somatic Polymorphism in Vitis vinifera L.

Through multiple vegetative propagation cycles, clones accumulate mutations in somatic cells that are at the origin of clonal phenotypic diversity in grape. Clonal diversity provided clones such as Cabernet-Sauvignon N°470, Chardonnay N° 548 and Pinot noir N° 777 which all produce wines of superior quality. The economic impact of clonal selection is therefore very high: since approx. 95% of the grapevines produced in French nurseries originate from the French clonal selection. In this study we provide the first broad description of polymorphism in different clones of a single grapevine cultivar, Pinot noir, in the context of vegetative propagation. Genome sequencing was performed using 454 GS-FLX methodology without a priori, in order to identify and quantify for the first time molecular polymorphisms responsible for clonal variability in grapevine. New generation sequencing (NGS) was used to compare a large portion of the genome of three Pinot noir clones selected for their phenotypic differences. Reads obtained with NGS and the sequence of Pinot noir ENTAV-INRA® 115 sequenced by Velasco et al., were aligned on the PN40024 reference sequence. We then searched for molecular polymorphism between clones. Three types of polymorphism (SNPs, Indels, mobile elements) were found but insertion polymorphism generated by mobile elements of many families displayed the highest mutational event with respect to clonal variation. Mobile elements inducing insertion polymorphism in the genome of Pinot noir were identified and classified and a list is presented in this study as potential markers for the study of clonal variation. Among these, the dynamic of four mobile elements with a high polymorphism level were analyzed and insertion polymorphism was confirmed in all the Pinot clones registered in France

Quels tests génétiques pour vos chevaux ?

National audienc

Test de dépistage des maladies génétiques

National audienc