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ABSTRACT: In southern Europe, orbiviral diseases such as bluetongue (BT) have been assumed to have been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer (Diptera: Ceratopogonidae). Recent outbreaks have occurred in regions where C. imicola is normally absent, supporting the theory that other species belonging to the Obsoletus or Pulicaris complexes may play a role in BT virus transmission. Investigations of the ecology of the species within the former group are hampered by females of member species being extremely difficult to separate by classical morphology. To allow straightforward separation of these species in France, a multiplex polymerase chain reaction-based on internal transcribed spacer (ITS)-1 rDNA was developed to distinguish between Culicoides chiopterus Meigen, Culicoides dewulfi Goetghebuer, Culicoides montanus Shakirjanova, Culicoides obsoletus Meigen, and Culicoides scoticus Downes & Kettle. This tool will be useful in defining both the vector role and larval biotopes of these species in Europe.
Journal of Medical Entomology 12/2007; 44(6):1019-25. · 1.76 Impact Factor
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Aurélie Perrin,
Emmanuel Albina,
Emmanuel Bréard,
Corinne Sailleau,
Sylvie Promé,
Colette Grillet,
Olivier Kwiatek,
Pierre Russo,
Richard Thiéry,
Stephan Zientara,
Catherine Cêtre-Sossah
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ABSTRACT: The development of recombinant capripoxviruses for protective immunization of ruminants against bluetongue virus (BTV) infection is described. Sheep (n=11) and goats (n=4) were immunized with BTV recombinant capripoxviruses (BTV-Cpox) individually expressing four different genes encoding two capsid proteins (VP2 and VP7) and two non-structural proteins (NS1, NS3) of BTV serotype 2 (BTV-2). Seroconversion was observed against NS3, VP7 and VP2 in both species and a lymphoproliferation specific to BTV antigens was also demonstrated in goats. Finally, partial protection of sheep challenged 3 weeks after BTV-Cpox administration with a virulent strain of BTV-2, was observed.
Vaccine 10/2007; 25(37-38):6774-83. · 3.77 Impact Factor
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ABSTRACT: Bluetongue (BT) and African Horse Sickness (AHS) are infectious arthropod-borne viral diseases affecting ruminants and horses, respectively. Culicoides imicola Kieffer, 1913, a biting midge, is the principal vector of these livestock diseases in Africa and Europe. Recently bluetongue disease has re-emerged in the Mediterranean Basin and has had a devastating effect on the sheep industry in Italy and on the islands of Sicily, Sardinia, Corsica and the Balearics, but fortunately, has not penetrated onto mainland France and Spain. To survey for the presence of C. imicola, an extensive light-trap network for the collection of Culicoides, was implemented in 2002 in southern mainland France. The morphological identification of Culicoides can be both tedious and time-consuming because its size ranges from 1.5 to 3 mm. Therefore, an ITS1 rDNA polymerase chain reaction (PCR)-based diagnostic assay was developed to rapidly and reliably identify Culicoides spp. and C. imicola. The aim of this work was to set up a rapid test for the detection of C. imicola amongst a pool of insects collected in areas at risk for BT. The sequence similarity of the rDNA (nuclear ribosomal DNA), which is greater within species than between species, is the foundation of its utilisation in species-diagnostic assays. The alignment of the 11 ITS1 sequences of Culicoides obtained from Genbank and EMBL databases helped us to identify one region in the 5' end and one in the 3' end that appear highly conserved. PCR primers were designed within these regions to amplify genus-specific fragments. In order to set up a C. imicola-specific PCR, another forward primer was designed and used in combination with the previously designed reverse primer. These primers proved to be highly specific and sensitive and permitted a rapid diagnostic separation of C. imicola from Culicoides spp.
Veterinary Research 35(3):325-37. · 4.06 Impact Factor
