End-point and real-time avian metapneumovirus (AMPV) RT-PCRs have been developed to detect one or two of the four recognized subgroups (A,B,C, and D) simultaneously or for broad range AMPV detection. Current subgroup specific tests target variable areas of the genome which makes these PCRs sensitive to specificity defects as recently documented. In the current study, a single five-plex digital droplet RT-PCR targeting the conserved viral polymerase gene of AMPV, which is less prone to genetic drift, has been designed.
View Article and Find Full Text PDFIn France during winter 2016-2017, 487 outbreaks of clade 2.3.4.
View Article and Find Full Text PDFDuring winter 2020-2021, France and other European countries were severely affected by highly pathogenic avian influenza H5 viruses of the Gs/GD/96 lineage, clade 2.3.4.
View Article and Find Full Text PDFAn H3N1 avian influenza virus was detected in a laying hens farm in May 2019 which had experienced 25% mortality in Northern France. The complete sequencing of this virus showed that all segment sequences belonged to the Eurasian lineage and were phylogenetically very close to many of the Belgian H3N1 viruses detected in 2019. The French virus presented two genetic particularities with NA and NS deletions that could be related to virus adaptation from wild to domestic birds and could increase virulence, respectively.
View Article and Find Full Text PDFImmunosuppression in poultry production is a recurrent problem worldwide, and one of the major viral immunosuppressive agents is Infectious Bursal Disease Virus (IBDV). IBDV infections are mostly controlled by using live-attenuated vaccines. Live-attenuated Infectious Bursal Disease (IBD) vaccine candidates are classified as "mild," "intermediate," "intermediate-plus" or "hot" based on their residual immunosuppressive properties.
View Article and Find Full Text PDFCurrently, turkey coronaviruses (TCoV) are isolated from homogenized intestines of experimentally infected embryos to ensure a maximum recovery of viral particles from all components of the intestines. However, the process of homogenization also ensures release of a significant amount of cellular RNAs into the sample that hinders downstream viral genome sequencing. This is especially the case for next generation sequencing (NGS) which sequences molecules at random.
View Article and Find Full Text PDFIn 2021, France faced large avian influenza outbreaks, like in 2016 and 2017. Controlling these outbreaks required the preventive depopulation of a large number of duck farms. A previous study in 2017 showed that the quality of decontamination of trucks and transport crates used for depopulation was often insufficient.
View Article and Find Full Text PDFAvian metapneumovirus (aMPV) is a viral pathogen that causes respiratory signs and drops in egg production most notably in turkeys but also affects chickens, ducks and other species. Four subgroups (aMPV-A, -B, -C and -D) have been characterized to date, which differ genetically, antigenically and in terms of geographic distribution and host range. Despite the rising awareness towards aMPV, many aspects of its epidemiology are still poorly understood.
View Article and Find Full Text PDFAvian influenza A viruses are a major threat to animal and public health. Since 1997, several highly pathogenic H5N1 avian viruses have been directly transmitted from poultry to humans, caused numerous human deaths, and had considerable economic impact on poultry markets. During 2015-2016, a highly pathogenic avian influenza outbreak occurred in southwestern France.
View Article and Find Full Text PDFTo date, four subgroups of avian metapneumoviruses have been defined (AMPV-A, B, C and D) based on genetic and antigenic differences. The extent of infection in the three principal species (turkeys, chickens and ducks) by these subgroups is, however, not well defined. Here, a series of controlled and ethically approved experimental infections were performed in specific pathogen-free turkeys, chickens and ducks with each of the four AMPV subgroups.
View Article and Find Full Text PDFMicrobiol Resour Announc
December 2018
Numerous viruses, mostly in mixed infections, have been associated worldwide with poult enteritis complex (PEC). In 2008 a coronavirus (Fr-TCoV 080385d) was isolated in France from turkey poults exhibiting clinical signs compatible with this syndrome. In the present study, the median infectious dose (ID ) transmission kinetics and pathogenicity of Fr-TCoV were investigated in 10-day-old SPF turkeys.
View Article and Find Full Text PDFInfectious bursal disease (IBD) is an immunosuppressive viral disease, present worldwide, which causes mortality and immunosuppression in young chickens. The causative agent, the Avibirnavirus IBDV, is a non-enveloped virus whose genome consists of two segments (A and B) of double-stranded RNA. Different pathotypes of IBDV exist, ranging from attenuated vaccine strains to very virulent viruses (vvIBDV).
View Article and Find Full Text PDFSeveral new highly pathogenic (HP) H5 avian influenza virus (AIV) have been detected in poultry farms from south-western France since November 2015, among which an HP H5N1. The zoonotic potential and origin of these AIVs immediately became matters of concern. One virus of each subtype H5N1 (150169a), H5N2 (150233) and H5N9 (150236) was characterised.
View Article and Find Full Text PDFInfectious bursal disease virus (IBDV) causes an economically significant disease of young chickens worldwide. The emergence of very virulent IBDV (vvIBDV) strains has brought more challenges for effective prevention and control of this disease. The aim of the present study was to characterize four IBDV isolates from various regions of China between late 1990s and recent years and to compare them with previously isolated European IBDV strains.
View Article and Find Full Text PDFFour avian metapneumovirus (AMPV) subgroups (A-D) have been reported previously based on genetic and antigenic differences. However, until now full length sequences of the only known isolates of European subgroup C and subgroup D viruses (duck and turkey origin, respectively) have been unavailable. These full length sequences were determined and compared with other full length AMPV and human metapneumoviruses (HMPV) sequences reported previously, using phylogenetics, comparisons of nucleic and amino acid sequences and study of codon usage bias.
View Article and Find Full Text PDFEU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks.
View Article and Find Full Text PDFTurkey coronavirus (TCoV) is a gammacoronavirus (Coronaviridae, Nidovirales) responsible for digestive disorders in young turkeys. TCoV has been associated with poult enteritis complex, a syndrome that severely affects turkey production. No medical prophylaxis exists to control TCoV, therefore sanitary measures such as cleaning and disinfection are essential.
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