48 research outputs found
The identification of a new genotype of avian paramyxoviruses type I in West-Africa provides new outcomes for phylogeny reconstruction
International audienc
Identification of a new reovirus causing tendinitis in broilers in France
Clinical cases of tendinitis have appear sporadically and then more regularly in broilers flocks
among different regions in France since 2010. These tendinitis have been identified as a consequence
of Reovirus infection despite the vaccination of breeders stock with vaccines containing different strains
of Reovirus previously described in the field ; additionnally an horizontal transmission, especially at
the time of hatch, has been observed. Virological studies conducted in two laboratories lead to the
identification of a new type of Reovirus non described in Europe until now. In addition to genetic
differences between this new virus and the vaccine strains used on the field, cross seroneutralisation
tests have shown antigenic differences which could explain the inefficacy of the vaccines used in the
field. In order to prevent the multiplication of theses viruses it seems usefull to update the composition
of vaccines for a better protection of breeders and their progenyDes cas cliniques de tendinite sont apparus sporadiquement, puis plus régulièrement, dans des élevages
de poulets de chair dans différentes régions de France depuis 2010. Ces tendinites ont été identifiées
comme dues à une réovirose en dépit de la vaccination des poules parentales avec des vaccins
contenant différentes valences de réovirus précédemment décrits comme présents sur le terrain ; en
outre une transmission horizontale notamment lors de l’éclosion a été observée. Les études virologiques
conduites dans deux laboratoires aboutissent Ă l’identification d’un nouveau rĂ©ovirus jusqu’Ă
présent non décrit en Europe. Outre des différences au plan génétique entre ce nouveau virus et les
souches vaccinales utilisées sur le terrain, des tests de séroneutralisation croisée ont montré des différences
antigéniques, ce qui peut expliquer l’inefficacité des vaccins observée sur le terrain. Pour prévenir
la multiplication de ces virus il apparait donc utile de réactualiser la composition des vaccins de
manière à protéger les poules reproductrices et leur descendanc
New avian paramyxoviruses type I strains identified in Africa provide new outcomes for phylogeny reconstruction and genotype classification
Newcastle disease (ND) is one of the most lethal diseases of poultry worldwide. It is caused by an avian paramyxovirus 1 that has high genomic diversity. In the framework of an international surveillance program launched in 2007, several thousand samples from domestic and wild birds in Africa were collected and analyzed. ND viruses (NDV) were detected and isolated in apparently healthy fowls and wild birds. However, two thirds of the isolates collected in this study were classified as virulent strains of NDV based on the molecular analysis of the fusion protein and experimental in vivo challenges with two representative isolates. Phylogenetic analysis based on the F and HN genes showed that isolates recovered from poultry in Mali and Ethiopia form new groups, herein proposed as genotypes XIV and sub-genotype VIf with reference to the new nomenclature described by Diel's group. In Madagascar, the circulation of NDV strains of genotype XI, originally reported elsewhere, is also confirmed. Full genome sequencing of five African isolates was generated and an extensive phylogeny reconstruction was carried out based on the nucleotide sequences. The evolutionary distances between groups and the specific amino acid signatures of each cluster allowed us to refine the genotype nomenclature. (Résumé d'auteur
Double introduction of highly pathogenic H5N1 avian influenza virus into France in early 2006
Foot-and-Mouth Disease Virus neutralizing antibodies production induced by pcDNA3 and Sindbis virus based plasmid encoding FMDV P1-2A3C3D in swine
An enzyme-linked immunosorbent assay for detection of avian influenza virus subtypes H5 and H7 antibodies
BACKGROUND: Avian influenza virus (AIV) subtypes H5 and H7 attracts particular attention because of the risk of their potential pathogenicity in poultry. The haemagglutination inhibition (HI) test is widely used as subtype specific test for serological diagnostics despite the laborious nature of this method. However, enzyme-linked immunosorbent assays (ELISAs) are being explored as an alternative test method. H5 and H7 specific monoclonal antibodies were experimentally raised and used in the development of inhibition ELISAs for detection of serological response specifically directed against AIV subtypes H5 and H7. The ELISAs were evaluated with polyclonal chicken anti-AIV antibodies against AIV subtypes: H1N2, H5N2, H5N7, H7N1, H7N7, H9N9, H10N4 and H16N3. RESULTS: Both the H5 and H7 ELISA proved to have a high sensitivity and specificity and the ELISAs detected H5 and H7 antibodies earlier during experimental infection than the HI test did. The reproducibility of the ELISA’s performed at different times was high with Pearson correlation coefficients of 0.96-0.98. CONCLUSIONS: The ELISAs are a potential alternative to the HI test for screening of large amounts of avian sera, although only experimental sera were tested in this study
Newcastle Disease Virus in Madagascar: Identification of an Original Genotype Possibly Deriving from a Died Out Ancestor of Genotype IV
In Madagascar, Newcastle disease (ND) has become enzootic after the first documented epizootics in 1946, with recurrent annual outbreaks causing mortality up to 40%. Four ND viruses recently isolated in Madagascar were genotypically and pathotypically characterised. By phylogenetic inference based on the F and HN genes, and also full-genome sequence analyses, the NDV Malagasy isolates form a cluster distant enough to constitute a new genotype hereby proposed as genotype XI. This new genotype is presumably deriving from an ancestor close to genotype IV introduced in the island probably more than 50 years ago. Our data show also that all the previously described neutralising epitopes are conserved between Malagasy and vaccine strains. However, the potential implication in vaccination failures of specific amino acid substitutions predominantly found on surface-exposed epitopes of F and HN proteins is discussed
Pseudorabies virus glycoprotein B can be used to carry foot and mouth disease antigens in DNA vaccination of pigs
Contribution de l'imagerie écho-doppler au diagnostic biologique de la fibrose hépatique
ANGERS-BU MĂ©decine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF