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Thierry Baldet - One of the best experts on this subject based on the ideXlab platform.
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spatio temporal genetic variation of the biting midge vector species Culicoides imicola ceratopogonidae kieffer in france
Parasites & Vectors, 2016Co-Authors: Stephanie Jacquet, Maria Goffredo, Helene Guis, Jérémy Bouyer, Karine Huber, Marielaure Setierrio, Xavier Allene, Ignace Rakotoarivony, Christine Chevillon, Thierry BaldetAbstract:Introduction of vector species into new areas represents a main driver for the emergence and worldwide spread of vector-borne diseases. This poses a substantial threat to livestock economies and public health. Culicoides imicola Kieffer, a major vector species of economically important animal viruses, is described with an apparent range expansion in Europe where it has been recorded in south-eastern continental France, its known northern distribution edge. This questioned on further C. imicola population extension and establishment into new territories. Studying the spatio-temporal genetic variation of expanding populations can provide valuable information for the design of reliable models of future spread. Entomological surveys and population genetic approaches were used to assess the spatio-temporal population dynamics of C. imicola in France. Entomological surveys (2–3 consecutive years) were used to evaluate population abundances and local spread in continental France (28 sites in the Var department) and in Corsica (4 sites). We also genotyped at nine microsatellite loci insects from 3 locations in the Var department over 3 years (2008, 2010 and 2012) and from 6 locations in Corsica over 4 years (2002, 2008, 2010 and 2012). Entomological surveys confirmed the establishment of C. imicola populations in Var department, but indicated low abundances and no apparent expansion there within the studied period. Higher population abundances were recorded in Corsica. Our genetic data suggested the absence of spatio-temporal genetic changes within each region but a significant increase of the genetic differentiation between Corsican and Var populations through time. The lack of intra-region population structure may result from strong gene flow among populations. We discussed the observed temporal variation between Corsica and Var as being the result of genetic drift following introduction, and/or the genetic characteristics of populations at their range edge. Our results suggest that local range expansion of C. imicola in continental France may be slowed by the low population abundances and unsuitable climatic and environmental conditions.
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Colonization of the Mediterranean basin by the vector biting midge species Culicoides imicola: an old story
Molecular Ecology, 2015Co-Authors: S. Jacquet, Claire Garros, Thierry Baldet, E. Lombaert, C. Walton, J. Restrepo, X. Allene, C. Cetre-sossah, A. Chaskopoulou, Jeanclaude DelecolleAbstract:Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970s. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the Late Pleistocene or Early Holocene through a single event of introduction; however, we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus.
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development and evaluation of a real time quantitative pcr assay for Culicoides imicola one of the main vectors of bluetongue bt and african horse sickness ahs in africa and europe
Research in Veterinary Science, 2008Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Colette Grillet, Marielaure Setierrio, Emmanuel AlbinaAbstract:Abstract The current microscopy method for identifying the Culicoides imicola Kieffer, 1913 species can be time and labour intensive. There is a need for the development of a rapid and quantitative tool to quantify the biting midges C. imicola ss in light trap catches. A reproducible and sensitive real-time polymerase chain reaction method that targets the internal transcribed spacer (ITS-1) of ribosomal DNA of C. imicola ss species was developed. This real-time PCR assay was first performed on 10-fold serial dilutions of purified plasmid DNA containing specific C. imicola ss ITS-1. It was then possible to construct standard curves with a high correlation coefficient (r2 = 0.99) in the range of 10−2–10−8 ng of purified DNA. The performances of this PCR were evaluated in comparison with morphological determination on Culicoides trapped along the Mediterranean coastal mainland France. ROC statistical analysis was carried out using morphology as gold standard and the area under the ROC curve had a satisfactory value of 0.9752. The results indicated that this real-time PCR assay holds promise for monitoring C. imicola ss population in both surveillance and research programmes because of its good specificity (92%) and sensitivity (95%).
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first record of Culicoides imicola the main vector of bluetongue virus in europe in the basque country northern spain
Veterinary Record, 2008Co-Authors: Arturo Goldarazena, Thomas Balenghien, Thierry Baldet, Pedro Romon, G Aduriz, Jeanclaude DelecolleAbstract:Culicoides imicola (Diptera: Ceratopogonidae) is the main vector of the bluetongue virus (btv), the causal agent of bluetongue, in southern Europe. This insect presents mainly an Afro-asian distribution, but it was first reported on mainland Europe in southern Spain ([Mellor and others 1983][1]) and
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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 larv...
Catherine Cetresossah - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a real time quantitative pcr assay for Culicoides imicola one of the main vectors of bluetongue bt and african horse sickness ahs in africa and europe
Research in Veterinary Science, 2008Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Colette Grillet, Marielaure Setierrio, Emmanuel AlbinaAbstract:Abstract The current microscopy method for identifying the Culicoides imicola Kieffer, 1913 species can be time and labour intensive. There is a need for the development of a rapid and quantitative tool to quantify the biting midges C. imicola ss in light trap catches. A reproducible and sensitive real-time polymerase chain reaction method that targets the internal transcribed spacer (ITS-1) of ribosomal DNA of C. imicola ss species was developed. This real-time PCR assay was first performed on 10-fold serial dilutions of purified plasmid DNA containing specific C. imicola ss ITS-1. It was then possible to construct standard curves with a high correlation coefficient (r2 = 0.99) in the range of 10−2–10−8 ng of purified DNA. The performances of this PCR were evaluated in comparison with morphological determination on Culicoides trapped along the Mediterranean coastal mainland France. ROC statistical analysis was carried out using morphology as gold standard and the area under the ROC curve had a satisfactory value of 0.9752. The results indicated that this real-time PCR assay holds promise for monitoring C. imicola ss population in both surveillance and research programmes because of its good specificity (92%) and sensitivity (95%).
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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 larv...
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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.
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phylogenetic analysis of Culicoides species from france based on nuclear its1 rdna sequences
Medical and Veterinary Entomology, 2006Co-Authors: Aurelie Perrin, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Catherine Cetresossah, Emmanuel AlbinaAbstract:Abstract. Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play important roles in the transmission of viral diseases affecting wild and domestic ruminants and horses, including Bluetongue (BT) and African horse sickness (AHS) respectively. In southern Europe, BT has been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer. However, other species such as C. obsoletus Meigen, C. scoticus Downs & Kettle and C. pulicaris Linne may also be involved in BTV transmission. As a consequence of the discovery of C. imicola followed by BTV-2 outbreaks on the island of Corsica in October 2000, further studies on these biting midges have been carried out. To better characterize the evolution and phylogenetic relations of Culicoides, molecular analysis in parallel with a morphology-based taxonomic approach were performed. Phylogenetic analyses of French Culicoides species were undertaken using the ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) as a molecular target. This region was shown to be useful in understanding evolutionary and genetic relationships between species. Construction of several trees showed that molecular phylogeny within the genus Culicoides correlates not only with morphological-based taxonomy but also with ecological patterns. (Resume d'auteur)
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molecular detection of Culicoides spp and Culicoides imicola the principal vector of bluetongue bt and african horse sickness ahs in africa and europe
Veterinary Research, 2004Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Aurelie Perrin, Colette Grillet, Emmanuel AlbinaAbstract: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-con- suming because its size ranges from 1.5 to 3 mm. Therefore, an ITS 1 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 ribos- omal 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 Gen- bank 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. molecular detection / Culicoides imicola / ITS1 / PCR / bluetongue
Bruno Mathieu - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a real time quantitative pcr assay for Culicoides imicola one of the main vectors of bluetongue bt and african horse sickness ahs in africa and europe
Research in Veterinary Science, 2008Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Colette Grillet, Marielaure Setierrio, Emmanuel AlbinaAbstract:Abstract The current microscopy method for identifying the Culicoides imicola Kieffer, 1913 species can be time and labour intensive. There is a need for the development of a rapid and quantitative tool to quantify the biting midges C. imicola ss in light trap catches. A reproducible and sensitive real-time polymerase chain reaction method that targets the internal transcribed spacer (ITS-1) of ribosomal DNA of C. imicola ss species was developed. This real-time PCR assay was first performed on 10-fold serial dilutions of purified plasmid DNA containing specific C. imicola ss ITS-1. It was then possible to construct standard curves with a high correlation coefficient (r2 = 0.99) in the range of 10−2–10−8 ng of purified DNA. The performances of this PCR were evaluated in comparison with morphological determination on Culicoides trapped along the Mediterranean coastal mainland France. ROC statistical analysis was carried out using morphology as gold standard and the area under the ROC curve had a satisfactory value of 0.9752. The results indicated that this real-time PCR assay holds promise for monitoring C. imicola ss population in both surveillance and research programmes because of its good specificity (92%) and sensitivity (95%).
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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 larv...
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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.
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application de la teledetection a l evaluation du risque d emergence d une maladie vectorielle introduction et diffusion dans le sud de la france de Culicoides imicola vecteur de la fievre catarrhale du mouton
Télédétection, 2007Co-Authors: Annelise Tran, Helene Guis, Bruno Mathieu, Bruno Barrague, Marielaure SetierrioAbstract:Cette etude a pour objet la definition d'un indicateur spatialise de risque de diffusion du moucheron vecteur de la fievre catarrhale du mouton (FCM), dans la region de Roquebrune-sur-Argens, departement du Var (France). La FCM est une maladie virale affectant les ruminants, principalement les ovins. Son emergence dans l'ouest du bassin mediterraneen depuis 1998 peut etre reliee a l'expansion de l'aire de repartition de son vecteur principal, le moucheron Culicoides imicola. L'installation reussie de populations de C. imicola dans le departement du Var, confirmee en 2005, augmente considerablement le risque d'introduction du virus de la FCM dans cette region. Afin de contribuer a l'evaluation de ce risque, des outils geomatiques ont ete utilises ici pour cartographier les zones ou C. imicola s'est potentiellement installe apres son introduction dans la zone cotiere. Considerant que la topographie et la categorie de couvert vegetal sont les principaux facteurs influant sur la dispersion des Culicoides a partir d'un point d'introduction, un indice de risque de diffusion a ete developpe tant a partir de parametres extraits d'un modele numerique d'altitude et de la classification d'une image satellitaire HRG de SPOT-5 a haute resolution spatiale, qu'a partir de donnees de piegeages entomologiques effectues en 2004. Les valeurs de cet indice ont ensuite ete comparees avec les donnees de piegeages entomologiques realises en 2005. Les resultats montrent une bonne concordance entre les valeurs de l'indice calcule et l'abondance de C. imicola observee en 2005. Les perspectives de cette etude, qui souligne l'interet d'integrer les outils geomatiques, dont la teledetection, dans les programmes de surveillance des maladies emergentes, sont discutees. (Resume d'auteur)
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phylogenetic analysis of Culicoides species from france based on nuclear its1 rdna sequences
Medical and Veterinary Entomology, 2006Co-Authors: Aurelie Perrin, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Catherine Cetresossah, Emmanuel AlbinaAbstract:Abstract. Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play important roles in the transmission of viral diseases affecting wild and domestic ruminants and horses, including Bluetongue (BT) and African horse sickness (AHS) respectively. In southern Europe, BT has been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer. However, other species such as C. obsoletus Meigen, C. scoticus Downs & Kettle and C. pulicaris Linne may also be involved in BTV transmission. As a consequence of the discovery of C. imicola followed by BTV-2 outbreaks on the island of Corsica in October 2000, further studies on these biting midges have been carried out. To better characterize the evolution and phylogenetic relations of Culicoides, molecular analysis in parallel with a morphology-based taxonomic approach were performed. Phylogenetic analyses of French Culicoides species were undertaken using the ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) as a molecular target. This region was shown to be useful in understanding evolutionary and genetic relationships between species. Construction of several trees showed that molecular phylogeny within the genus Culicoides correlates not only with morphological-based taxonomy but also with ecological patterns. (Resume d'auteur)
Jeanclaude Delecolle - One of the best experts on this subject based on the ideXlab platform.
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Colonization of the Mediterranean basin by the vector biting midge species Culicoides imicola: an old story
Molecular Ecology, 2015Co-Authors: S. Jacquet, Claire Garros, Thierry Baldet, E. Lombaert, C. Walton, J. Restrepo, X. Allene, C. Cetre-sossah, A. Chaskopoulou, Jeanclaude DelecolleAbstract:Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970s. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the Late Pleistocene or Early Holocene through a single event of introduction; however, we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus.
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development and evaluation of a real time quantitative pcr assay for Culicoides imicola one of the main vectors of bluetongue bt and african horse sickness ahs in africa and europe
Research in Veterinary Science, 2008Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Colette Grillet, Marielaure Setierrio, Emmanuel AlbinaAbstract:Abstract The current microscopy method for identifying the Culicoides imicola Kieffer, 1913 species can be time and labour intensive. There is a need for the development of a rapid and quantitative tool to quantify the biting midges C. imicola ss in light trap catches. A reproducible and sensitive real-time polymerase chain reaction method that targets the internal transcribed spacer (ITS-1) of ribosomal DNA of C. imicola ss species was developed. This real-time PCR assay was first performed on 10-fold serial dilutions of purified plasmid DNA containing specific C. imicola ss ITS-1. It was then possible to construct standard curves with a high correlation coefficient (r2 = 0.99) in the range of 10−2–10−8 ng of purified DNA. The performances of this PCR were evaluated in comparison with morphological determination on Culicoides trapped along the Mediterranean coastal mainland France. ROC statistical analysis was carried out using morphology as gold standard and the area under the ROC curve had a satisfactory value of 0.9752. The results indicated that this real-time PCR assay holds promise for monitoring C. imicola ss population in both surveillance and research programmes because of its good specificity (92%) and sensitivity (95%).
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first record of Culicoides imicola the main vector of bluetongue virus in europe in the basque country northern spain
Veterinary Record, 2008Co-Authors: Arturo Goldarazena, Thomas Balenghien, Thierry Baldet, Pedro Romon, G Aduriz, Jeanclaude DelecolleAbstract:Culicoides imicola (Diptera: Ceratopogonidae) is the main vector of the bluetongue virus (btv), the causal agent of bluetongue, in southern Europe. This insect presents mainly an Afro-asian distribution, but it was first reported on mainland Europe in southern Spain ([Mellor and others 1983][1]) and
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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 larv...
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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.
Emmanuel Albina - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a real time quantitative pcr assay for Culicoides imicola one of the main vectors of bluetongue bt and african horse sickness ahs in africa and europe
Research in Veterinary Science, 2008Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Colette Grillet, Marielaure Setierrio, Emmanuel AlbinaAbstract:Abstract The current microscopy method for identifying the Culicoides imicola Kieffer, 1913 species can be time and labour intensive. There is a need for the development of a rapid and quantitative tool to quantify the biting midges C. imicola ss in light trap catches. A reproducible and sensitive real-time polymerase chain reaction method that targets the internal transcribed spacer (ITS-1) of ribosomal DNA of C. imicola ss species was developed. This real-time PCR assay was first performed on 10-fold serial dilutions of purified plasmid DNA containing specific C. imicola ss ITS-1. It was then possible to construct standard curves with a high correlation coefficient (r2 = 0.99) in the range of 10−2–10−8 ng of purified DNA. The performances of this PCR were evaluated in comparison with morphological determination on Culicoides trapped along the Mediterranean coastal mainland France. ROC statistical analysis was carried out using morphology as gold standard and the area under the ROC curve had a satisfactory value of 0.9752. The results indicated that this real-time PCR assay holds promise for monitoring C. imicola ss population in both surveillance and research programmes because of its good specificity (92%) and sensitivity (95%).
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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 larv...
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molecular identification of western european species of obsoletus complex diptera ceratopogonidae by an internal transcribed spacer 1 rdna multiplex polymerase chain reaction assay
Journal of Medical Entomology, 2007Co-Authors: Bruno Mathieu, Thierry Baldet, Jeanclaude Delecolle, Aurelie Perrin, Emmanuel Albina, Catherine CetresossahAbstract: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.
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phylogenetic analysis of Culicoides species from france based on nuclear its1 rdna sequences
Medical and Veterinary Entomology, 2006Co-Authors: Aurelie Perrin, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Catherine Cetresossah, Emmanuel AlbinaAbstract:Abstract. Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play important roles in the transmission of viral diseases affecting wild and domestic ruminants and horses, including Bluetongue (BT) and African horse sickness (AHS) respectively. In southern Europe, BT has been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer. However, other species such as C. obsoletus Meigen, C. scoticus Downs & Kettle and C. pulicaris Linne may also be involved in BTV transmission. As a consequence of the discovery of C. imicola followed by BTV-2 outbreaks on the island of Corsica in October 2000, further studies on these biting midges have been carried out. To better characterize the evolution and phylogenetic relations of Culicoides, molecular analysis in parallel with a morphology-based taxonomic approach were performed. Phylogenetic analyses of French Culicoides species were undertaken using the ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) as a molecular target. This region was shown to be useful in understanding evolutionary and genetic relationships between species. Construction of several trees showed that molecular phylogeny within the genus Culicoides correlates not only with morphological-based taxonomy but also with ecological patterns. (Resume d'auteur)
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molecular detection of Culicoides spp and Culicoides imicola the principal vector of bluetongue bt and african horse sickness ahs in africa and europe
Veterinary Research, 2004Co-Authors: Catherine Cetresossah, Thierry Baldet, Jeanclaude Delecolle, Bruno Mathieu, Aurelie Perrin, Colette Grillet, Emmanuel AlbinaAbstract: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-con- suming because its size ranges from 1.5 to 3 mm. Therefore, an ITS 1 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 ribos- omal 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 Gen- bank 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. molecular detection / Culicoides imicola / ITS1 / PCR / bluetongue