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Corinne Sailleau,
Gina Zanella, Emmanuel Breard,
Cyril Viarouge,
Alexandra Desprat,
Damien Vitour,
Micheline Adam,
Laurent Lasne,
Arnaud Martrenchar,
Labib Bakkali-Kassimi,
Laura Costes,
Stéphan Zientara
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ABSTRACT: Bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) in deer have already been isolated in Reunion Island and have caused more or less severe clinical signs in cattle (EHDV) or in sheep (BTV), as observed in 2003. In January 2009, cattle in Reunion Island showed clinical signs suggesting infection by one or the other of these arboviral diseases. A study was set up to determine the etiology of the disease. Analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on blood samples from 116 cattle from different districts of the island detected the presence of the EHDV genome in 106 samples and, in 5 of them, the simultaneous occurrence of BTV and EHDV. One strain of EHDV (7 isolates) and one of BTV were isolated in embryonated eggs and a BHK-21 cell culture. Group and subgroup primer-pairs were designed on the segment 2 sequences available in GenBank to identify and type the EHDV strains. Phylogenetic analysis of the genomic segment 2 (encoding the VP2 serotype-specific protein) of the isolates confirmed the serotypes of these two orbiviruses as BTV-2 and EHDV-6 and allowed them to be compared with previously isolated strains.
Veterinary Microbiology 03/2012; 155(2-4):191-7. · 3.33 Impact Factor
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ABSTRACT: An antigen delivery system based on subviral particles formed by the self-assembly of the capsid protein of infectious bursal disease virus and carrying foreign peptides at the top of the projection domain was investigated. We report here the effective insertion of the foot-and-mouth disease virus (FMDV) immunodominant epitope in one of the four external loops of the subviral particles. Out of the two loops tested, one of them tolerated an insert of 12 amino acids without disrupting the subviral particle assembly. The subviral particles reacted with neutralizing FMDV type O1 monoclonal and polyclonal antibodies and elicited a neutralizing antibody response in immunized mice. Furthermore, we found that they have the potential for the detection of FMDV antibodies in a competitive ELISA for diagnostic.
Vaccine 12/2008; 27(1):93-8. · 3.77 Impact Factor
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ABSTRACT: The nucleotide sequences of genome segments 2, 7, 8, 9 and 10, coding for viral proteins (VP) and non-structural proteins (NS)--VP2, VP7, NS2, VP6 and NS3/NS3A, respectively, were determined and compared for 10 strains of bluetongue virus (BTV) serotype 4 isolated in the Mediterranean Basin between 1979 and 2004, and the South African attenuated BTV 4 vaccine strain. The sequence data generated for the BTV 4 strains isolated in Greece in 1979, 1999 and 2000 showed that they had a common origin but were distinct from the lineage of the BTV 4 strains isolated from 2003 onward in the western Mediterranean Basin (Italy, Morocco, Spain and Corsica). The nucleotide and deduced amino acid (aa) sequences of the BTV 4 strains within each lineage were identical to each other, irrespective of the year of isolation or the geographical location. Although the sequence of VP2 from the Turkish and Greek strains were highly similar, there were sufficient differences in the VP6, VP7 and NS2 proteins to suggest that the Turkish BTV 4 belongs to a third lineage. Alignment of the NS3 sequences from the attenuated BTV 4 vaccine strain and the field strains showed 13 aa substitutions, which may, either singularly or together, be responsible for attenuation and hence determining the virulence of the virus.
Virus Research 06/2007; 125(2):191-7. · 2.94 Impact Factor
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ABSTRACT: Bluetongue (BT) and/or BT viruses (BTV) have been identified in the Mediterranean basin and the Balkans each year from 1998 to 2002 and in particular BTV serotype 2 in the French Island of Corsica (2000 and 2001). In response to these virus incursions, the French Veterinary Authorities carried out epidemiological studies that included virological, serological and entomological analysis, and two vaccination campaigns performed in the winter of 2000/2001 and the winter and spring of 2001 and 2002. Rapid and reliable serotype differentiation is essential at the start of an outbreak to allow an early selection of vaccine to control the spread of the virus. Thus, molecular tools, that complement conventional methods, have been developed for early detection of infection, determination of the serotype, and differentiation between natural infection and vaccination. Serological results showed that the first vaccination campaign during the winter of 2000/2001 did not provide full protection for all sheep and during the summer of 2001, 335 sheep flocks in Corsica were again infected by BTV 2 (7-fold more that in 2000). Entomological studies have demonstrated that the only proven vector of the disease, Culicoides imicola, was present in the island in 2000 and that it has successfully established itself in Corsica. The safety and immunogenicity of the commercial South African vaccine were studied. Fourteen sheep were vaccinated and then observed for clinical signs. Blood, sera, spleen and lymph nodes were collected and analyzed, and the results confirmed the safety and potency of using this vaccine to protect sheep from clinical disease. As a result, an intensive vaccination campaign was performed during winter and spring 2001/2002. No cases of BT had been observed by the end of summer 2002, indicating that the vaccination campaign has been successful in protecting sheep from infection.
Research in Veterinary Science 09/2004; 77(1):1-8. · 1.65 Impact Factor
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Damien Vitour,
Jean Guillotin,
Corinne Sailleau,
Cyril Viarouge,
Alexandra Desprat,
Frédéric Wolff,
Guillaume Belbis,
Benoit Durand,
Labib Bakkali-Kassimi, Emmanuel Breard,
Stéphan Zientara,
Gina Zanella
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ABSTRACT: ABSTRACT: Since its introduction into northern Europe in 2006, bluetongue has become a major threat to animal health. While the efficacy of commercial vaccines has been clearly demonstrated in livestock, little is known regarding the effect of maternal immunity on vaccinal efficacy. Here, we have investigated the duration and amplitude of colostral antibody-induced immunity in calves born to dams vaccinated against bluetongue virus serotype 8 (BTV-8) and the extent of colostral antibody-induced interference of vaccination in these calves. Twenty-two calf-cow pairs were included in this survey. The median age at which calves became seronegative for BTV was 84 and 112 days as assayed by seroneutralisation test (SNT) and VP7 BTV competitive ELISA (cELISA), respectively. At the mean age of 118 days, 13/22 calves were immunized with inactivated BTV-8 vaccine. In most calves vaccination elicited a weak immune response, with seroconversion in only 3/13 calves. The amplitude of the humoral response to vaccination was inversely proportional to the maternal antibody level prior to vaccination. Thus, the lack of response was attributed to the persistence of virus-specific colostral antibodies that interfered with the induction of the immune response. These data suggest that the recommended age for vaccination of calves born to vaccinated dams needs to be adjusted in order to optimize vaccinal efficacy.
Veterinary Research 42(1):18. · 4.06 Impact Factor
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ABSTRACT: The nucleotide sequences of genome segments 2, 7, 8, 9 and 10, coding for viral proteins (VP) and non-structural proteins (NS)—VP2, VP7, NS2, VP6 and NS3/NS3A, respectively, were determined and compared for 10 strains of bluetongue virus (BTV) serotype 4 isolated in the Mediterranean Basin between 1979 and 2004, and the South African attenuated BTV 4 vaccine strain. The sequence data generated for the BTV 4 strains isolated in Greece in 1979, 1999 and 2000 showed that they had a common origin but were distinct from the lineage of the BTV 4 strains isolated from 2003 onward in the western Mediterranean Basin (Italy, Morocco, Spain and Corsica). The nucleotide and deduced amino acid (aa) sequences of the BTV 4 strains within each lineage were identical to each other, irrespective of the year of isolation or the geographical location. Although the sequence of VP2 from the Turkish and Greek strains were highly similar, there were sufficient differences in the VP6, VP7 and NS2 proteins to suggest that the Turkish BTV 4 belongs to a third lineage. Alignment of the NS3 sequences from the attenuated BTV 4 vaccine strain and the field strains showed 13 aa substitutions, which may, either singularly or together, be responsible for attenuation and hence determining the virulence of the virus.
Virus Research.
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