References of "Hamers, C"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSequence-optimised E2 constructs from BVDV-1b and BVDV-2 for DNA immunisation in cattle
Couvreur, B.; Letellier, C.; Olivier, Fabrice ULg et al

in Veterinary Research (2007), 38(6, NOV-DEC), 819-834

We report DNA immunisation experiments in cattle using plasmid constructs that encoded glycoprotein E2 from bovine viral diarrhoea virus (BVDV)-1 (E2.1) and BVDV-2 (E2.2). The coding sequences were ... [more ▼]

We report DNA immunisation experiments in cattle using plasmid constructs that encoded glycoprotein E2 from bovine viral diarrhoea virus (BVDV)-1 (E2.1) and BVDV-2 (E2.2). The coding sequences were optimised for efficient expression in mammalian cells. A modified leader peptide sequence from protein gD of BoHV1 was inserted upstream of the E2 coding sequences for efficient membrane export of the proteins. Recombinant E2 were efficiently expressed in COS7 cells and they presented the native viral epitopes as judged by differential recognition by antisera from cattle infected with BVDV-1 or BVDV-2. Inoculation of pooled plasmid DNA in young cattle elicited antibodies capable of neutralising viral strains representing the major circulating BVDV genotypes. [less ▲]

Detailed reference viewed: 26 (3 ULg)
Full Text
Peer Reviewed
See detailPoint mutations in an infectious bovine viral diarrhoea virus type 2 cDNA transcript that yields an attenuated and protective viral progeny
Dehan, Pierre ULg; Couvreur, B.; Hamers, C. et al

in Vaccine (2005), 23(33), 4236-4246

An infectious cDNA clone of the hypervirulent bovine viral diarrhoea virus (BVDV) strain 890 (isolate 256) was produced by a streamlined PCR procedure. As compared to the published sequence of strain 890 ... [more ▼]

An infectious cDNA clone of the hypervirulent bovine viral diarrhoea virus (BVDV) strain 890 (isolate 256) was produced by a streamlined PCR procedure. As compared to the published sequence of strain 890, the nucleotide sequencing of cloned cDNA corresponding to isolate 256 revealed several mutations seven of which were attributed to the cloning procedure. The infectious transcript was transfected into permissive cells and led to viral multiplication (AvrII+ strain). In vitro, viral titres reached by the parental strain exceed those of the AvrII+ strain by more than one order of magnitude. The latter was clearly less virulent to young calves as indicated by clinical, haematological and virological parameters. Thirty-four days after inoculation with AvrII+ strain, calves were challenged with the virulent parental strain. The animals were protected as compared to unvaccinated controls. Therefore, our approach led to the production of an attenuated strain with potential use as a vaccine strain and will be useful for studies of virulence determinants in BVDV-2. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 26 (3 ULg)
See detailDiarrhée virale bovine et maladie des muqueuses
Pastoret, Paul-Pierre ULg; Hamers, C.; Dehan, Pierre ULg

in Lefevre, P.-C.; Blancou, J.; Chermette, R. (Eds.) Principales maladies infectieuses et parasitaires du bétail (2003)

Detailed reference viewed: 13 (2 ULg)
Full Text
Peer Reviewed
See detailVirus neutralising antibodies against 22 bovine viral diarrhoea virus isolates in vaccinated calves
Hamers, C.; Di Valentin, Emmanuel ULg; Dumont, Chloé ULg et al

in Veterinary Journal (2002), 163(1), 61-67

Seven of nine colostrum deprived calves, free from bovine viral diarrhoea virus (BVDV), were vaccinated with a commercially available vaccine containing two inactivated strains of BVDV, an inactivated ... [more ▼]

Seven of nine colostrum deprived calves, free from bovine viral diarrhoea virus (BVDV), were vaccinated with a commercially available vaccine containing two inactivated strains of BVDV, an inactivated strain of bovine herpesvirus-1 and modified-live strains of bovine respiratory syncytial virus and para-influenza-3 virus. The two other calves were kept as controls. The virus neutralising (VN) antibodies induced by vaccination were tested against 22 antigenically diverse BVDV isolates, including reference strains and field isolates, both cytopathic and non-cytopathic, as well as genotypes I and II. The strains were isolated in Belgium, France, Germany, the United Kingdom and the USA. While there were variations in the VN titres of the individual calves against all the strains, serum from the seven animals neutralised 20 or more of the strains tested. From the results, it can be concluded that the vaccine can stimulate the production of VN antibodies capable of neutralising a wide range of European and American isolates of BVDV, including genotypes I and II. [less ▲]

Detailed reference viewed: 16 (6 ULg)
Peer Reviewed
See detailDiversity among Bovine Pestiviruses
Hamers, C.; Dehan, Pierre ULg; Couvreur, B. et al

in Veterinary Journal (2001), 161(2), 112-22

Bovine viral diarrhoea virus (BVDV) isolates are characterized by an important genetic, antigenic and pathogenic diversity. The emergence of new hypervirulent BVDV strains in North America has provided ... [more ▼]

Bovine viral diarrhoea virus (BVDV) isolates are characterized by an important genetic, antigenic and pathogenic diversity. The emergence of new hypervirulent BVDV strains in North America has provided clear evidence of pathogenic differences between BVDV strains. The origin of BVDV diversity is related to high mutation rate occurring in RNA viruses but the consequences of mutations obviously depend on the genes which are involved. Mutations in genes encoding for structural proteins of immunological importance may have practical implications.Knowledge of BVDV diversity is important for understanding the wide variety of pathogenesis of diseases caused by the virus, for monitoring the epidemiology of the different types and for the design of optimum laboratory tests and vaccines.This review focuses on the origin and consequences of BVDV diversity with regard to pathogenesis, biotypes, and antigenic and genetic variations. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Peer Reviewed
See detailAvancées récentes en biologie moléculaire du virus de la diarrhée virale bovine
Dehan, Pierre ULg; Hamers, C.; Couvreur, B. et al

in Annales de Médecine Vétérinaire (2001), 145

Detailed reference viewed: 16 (5 ULg)
Full Text
Peer Reviewed
See detailVirus Neutralizing Antibodies against a Panel of 18 Bvdv Isolates in Calves Vaccinated with Rispoval Rs-Bvd
Hamers, C.; Di Valentin, Emmanuel ULg; Dumont, Chloé ULg et al

in Journal of Veterinary Medicine. B, Infectious Diseases & Veterinary Public Health (2000), 47(10), 721-6

Seven of nine colostrum-deprived calves, free from infection with bovine virus diarrhoea virus (BVDV), were vaccinated with Rispoval RS-BVD on two occasions, 21 days apart, while the other two were kept ... [more ▼]

Seven of nine colostrum-deprived calves, free from infection with bovine virus diarrhoea virus (BVDV), were vaccinated with Rispoval RS-BVD on two occasions, 21 days apart, while the other two were kept as BVDV infection controls. The virus neutralizing (VN) serum antibodies induced by vaccination were tested for their ability to neutralize 18 European BVDV isolates, including laboratory reference strains and recent field isolates, both cytopathic and non-cytopathic biotypes as well as genotypes I and II. The strains were isolated in Belgium, France, Germany and the United Kingdom. While there were large variations in the vaccine-induced VN titres of the individual calves against all the strains, e.g. the titres against Osloss NCP, the European reference strain ranged from 1.7 to 6.7 (1:log2), serum from each animal was capable of neutralizing between nine and all 18 of the strains tested. Nevertheless, from the results of this study, it can be concluded that in colostrum-deprived BVDV seronegative calves, Rispoval RS-BVD can stimulate the production of VN antibodies capable of neutralizing a wide range of antigenically diverse European isolates of BVDV, including genotypes I and II. [less ▲]

Detailed reference viewed: 16 (2 ULg)
Peer Reviewed
See detailDifferences in Experimental Virulence of Bovine Viral Diarrhoea Viral Strains Isolated from Haemorrhagic Syndromes
Hamers, C.; Couvreur, B.; Dehan, Pierre ULg et al

in Veterinary Journal (2000), 160(3), 250-8

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To ... [more ▼]

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To compare the pathogenic characters of the North American and European hypervirulent strains, we inoculated BVDV naive calves with BVDV strains isolated from haemorrhagic syndromes originating in Belgium, France and the USA. The experimental procedure comprised daily clinical examination and measurement of blood and virological parameters.The American BVD890/256 strain induced severe thrombocytopaenia, profuse diarrhoea and pneumonia in all calves, indicating that hypervirulent BVDV could be the primary infectious agent of pneumonia. Interestingly, a strong correlation was observed between the intense viraemia and a decreased platelet count. None of the European strains tested induced significant pathological signs, although isolated from cases presenting haemorrhagic syndrome. [less ▲]

Detailed reference viewed: 14 (3 ULg)