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Emmanuel Albina - One of the best experts on this subject based on the ideXlab platform.
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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
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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 Cêtre-sossah, 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-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.
Jordi Figuerola - One of the best experts on this subject based on the ideXlab platform.
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Genetic characterization and molecular identification of the bloodmeal sources of the potential Bluetongue vector Culicoides obsoletus in the Canary Islands, Spain
2020Co-Authors: Josué Martínez-de La Puente, Martina Ferraguti, Javier Martínez, Antonio Morales-de La Nuez, Noemí Castro, Jordi FiguerolaAbstract:Abstract Background: Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including Bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of Bluetongue Disease (BTD), Spain and Europe have had to face up to a spread of Bluetongue with disastrous consequences. Therefore, it is essential to identify the distribution of biting midges and understand their feeding patterns in areas susceptible to BTD. To that end, we captured biting midges on two farms in the Canary Islands (i) to identify the midge species in question and characterize their COI barcoding region and (ii) to ascertain the source of their bloodmeals using molecular tools
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first molecular identification of the vertebrate hosts of culicoides imicola in europe and a review of its blood feeding patterns worldwide implications for the transmission of Bluetongue Disease and african horse sickness
Medical and Veterinary Entomology, 2017Co-Authors: Martinezde J La Puente, Javier Navarro, Martina Ferraguti, Ramon C Soriguer, Jordi FiguerolaAbstract:Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause Bluetongue Disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.
Heinz Mehlhorn - One of the best experts on this subject based on the ideXlab platform.
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Bluetongue Disease in germany 2007 2008 monitoring of entomological aspects
Parasitology Research, 2009Co-Authors: Heinz Mehlhorn, Volker Walldorf, Sven Klimpel, Gunter A Schaub, Ellen Kiel, Rene Focke, Gabriele Liebisch, Arndt Liebisch, Doreen Werner, C BauerAbstract:In the summer of 2006, a Bluetongue epidemic started in the border area of Belgium, The Netherlands, and Germany, spread within 2 years over large areas of Western and Central Europe, and caused substantial losses in farm ruminants. Especially sheep and cattle were severely affected, leading to a case–fatality ratio of nearly 40% in sheep (Conraths et al., Emerg Inf Dis 15(3):433–435, 2009). The German federal ministry of food, agriculture, and consumer protection (BMELV) established a countrywide monitoring on the occurrence of the vectors of this virus, i.e., midges (family Ceratopogonidae) of the genus Culicoides. The monitoring was done on 91 sites, most of which were localized in the 150-km restriction zone that existed in December 2006. A grid consisting of 45 × 45 km2 cells was formed that covered the monitoring area. As a rule, one trap was placed into each grid cell. The monitoring program started at the end of March 2007 and lasted until May 2008. It included the catching of midges by ultraviolet light traps—done each month from days 1 until 8, the selection of midges of the Culicoides obsoletus, Culicoides pulicaris group, and other Culicoides spp., the testing of midges for Bluetongue virus (BTV) by polymerase chain reaction (PCR), and the daily registration of weather data at each trap site for the whole monitoring period. The following main results were obtained: (1) Members of the C. obsoletus group were most commonly found in the traps, reaching often 3/4 of the catches. The African and South European vector of BTV—the species Culicoides imicola—was never found. (2) Members of the C. obsoletus group were most frequently found infected with BTV besides a few cases in the C. pulicaris group and other species. (3) Members of the C. obsoletus group were also found in winter. Their numbers were reduced, however, and they were caught mostly close to stables. Therefore, a true midge-free period does not exist during the year in Germany. (4) The amounts of midges caught daily depended on the weather conditions. If it was cold and/or windy, the traps contained only a few specimens. Since the months from January to May 2008 were considerably colder (at all farms) than their correspondents in 2007, the growing of the population of midges started 2–3 months later in 2008 than in 2007. (5) The highest populations of midges occurred in both years (2007 and 2008) during the months September and October. This corresponded significantly to the finding of highest numbers of infected midges and to the number of Diseased cattle and sheep during these 2 months. (6) It is noteworthy that in general, the first virus-positive midges of the species C. obsoletus were found about 1 1/2 months later than the first clinical cases had occurred or later than the first PCR-proven virus-positive sentinel animals had been documented. In 2007, the first BTV-positive cattle were detected in May in North Rhine-Westphalia, while the first positive Culicoides specimens were only found in August on the same farm. Evaluating these main results of the entomological monitoring and the fact that many wild ruminants have also been infected with BTV, it becomes evident that Bluetongue Disease has become endemic in Central Europe, and that only constant effort including vaccination and perhaps also insecticidal protection of cattle and sheep will keep the economical losses at a reasonable level. The following papers (1–10) in this journal will contribute more details obtained from this worldwide unique entomological monitoring: Bartsch et al. 2009; Bauer et al. 2009; Stephan et al. 2009; Clausen et al. 2009; Horbrand and Geier 2009; Kiehl et al. 2009; Mehlhorn et al. 2009; Kiel et al. 2009; Vorsprach et al. 2009; Balczun et al. 2009.
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effects of permethrin flypor and fenvalerate acadrex 60 arkofly on culicoides species the vector of Bluetongue virus
Parasitology Research, 2009Co-Authors: Günter Schmahl, Volker Walldorf, Sven Klimpel, Barbel Schumacher, Antja Jatzlau, Saleh Alquraishy, Heinz MehlhornAbstract:Bluetongue Disease struggles ruminants in Europe since summer 2006, introducing high levels of morbidity and mortality. Besides vaccination, the application of insecticides is another means to protect cattle and sheep from infections with the Bluetongue virus, which is transmitted in Europe by female specimens of Culicoides species (Culicoides obsoletus and in a few cases of Culicoides pulicaris and Culicoides dewulfi). The present study deals with the effects of permethrin (Flypor®) and fenvalerate (Arkofly®, Acadrex® 60) on freshly caught Culicoides specimens when brought into contact for 15, 30, 60 or 120 s with hair of cattle or sheep treated topically 7,14, 21, 28 or 35 days before. The experiments clearly showed that the lege arte application of these compounds (products) onto the hair of the experimental animals succeeds in killing Culicoides specimens when brought into contact with hair from feet of animals being treated even 35 days before. This test was needed to make sure that the products do reach the feet and belly of the animals in sufficient amounts, since this region is the predominant biting site of the Culicoides midges.
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Outbreak of Bluetongue Disease (BTD) in Germany and the danger for Europe
Parasitology Research, 2008Co-Authors: Heinz Mehlhorn, Volker Walldorf, Sven Klimpel, Günter SchmahlAbstract:In August 2006, the blue tongue virus (BTV-type South Africa serotype 8) was detected for the first time in cattle blood probes in the Netherlands, immediately followed by cases in Belgium and in cattle on German farms, which were situated close to Aachen at the border to those countries. Within less than 2 months the Disease spread eastwards crossing the Rhine, southwards to Luxemburg and to Northern France. At the end of the year 2006, nearly 1,000 farms were affected in Germany. Catches on two German cattle farms proved that the ceratopogonid species Culicoides obsoletus was obviously the vector, since many females—fed and unfed ones—were found to be infected with this virus. This sudden outbreak of Bluetongue Disease (BTD) is surely not a primary result of global warming, but rather an effect of globalization—i.e. the intensive worldwide import and export of animals; but a hot summer, as in 2006, and a warm winter like that of the years 2006/2007 supported the new spread starting again in masses in August 2007 leading to 596 PCR-confirmed cases until then with more than 200,000 animals infected. Thus, new agents coming from elsewhere have only a chance to spread if appropriate vectors are available and the conditions remain favourable during a reasonably long period. Effects of global warming—of course—will support persistence of such outbreaks of Diseases due to offering of spreading of imported viruses, bacteria and/or parasites.
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First occurrence of Culicoides obsoletus-transmitted Bluetongue virus epidemic in Central Europe
Parasitology Research, 2007Co-Authors: Heinz Mehlhorn, Bernd Hoffmann, Volker Walldorf, Sven Klimpel, Birgit Jahn, Friedhelm Jaeger, Josef Eschweiler, Martin BeerAbstract:In August 2006, Bluetongue virus Disease (BTD) was detected for the first time in the Netherlands, Belgium, Germany and Northern France. Serological tests as well as reverse transcriptase polymerase chain reaction (RT-PCR) proved the occurrence of Bluetongue virus (BTV) in Diseased sheep and cattle, and the virus was identified as serotype 8. Therefore, the search for possible vectors was immediately initiated in the outbreak region in Germany. Traps with automatically regulated ultraviolet light lamps were placed at two different farms with sero-positive cattle, and insect monitoring was done from August 2006 until January 2007. The caught arthropods were weekly determined, and it could be observed that midges of the dipteran family Ceratopogonidae occurred in large numbers, sometimes representing up to 40% of all individuals. The microscopical analysis of the wing morphology showed that the species (complex) Culicoides obsoletus was most abundant covering about 97% of the analysed midges. On the second place ranged C. pulicaris , while C. nubeculosus and C. festivipennis were found only as single individuals. Fed and unfed females were separated, sent to the National Reference Laboratory for Bluetongue Disease (Friedrich-Loeffler-Institut, Isle of Riems, Germany) and investigated with a BTV-8-specific real-time RT-PCR. It could be demonstrated that at both farms both fed and unfed C. obsoletus were tested positive for BTV-8 genomes, while none of the other species scored positive. This finding strongly supports that the BTD-epidemic, which reached in the meantime wide regions of North Rhine–Westphalia in Germany and of the neighbouring countries with several hundreds of affected farms, is initiated by virus transmission during the blood meal of midges of the C. obsoletus complex. Since they were captured still at the 21st of December close to cattle with clinical signs, it must be feared that BTV-8 is now established in Central Europe, where it had been absent until now.
Bernd Hoffmann - One of the best experts on this subject based on the ideXlab platform.
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PCR identification of culicoid biting midges (Diptera, Ceratopogonidae) of the Obsoletus complex including putative vectors of Bluetongue and Schmallenberg viruses
Parasites & Vectors, 2012Co-Authors: Kathrin Lehmann, Bernd Hoffmann, Doreen Werner, Helge KampenAbstract:Background Biting midges of the Obsoletus species complex of the ceratopogonid genus Culicoides were assumed to be the major vectors of Bluetongue virus (BTV) in northern and central Europe during the 2006 outbreak of Bluetongue Disease (BT). Most recently, field specimens of the same group of species have also been shown to be infected with the newly emerged Schmallenberg virus (SBV) in Europe. A reliable identification of the cryptic species of this group is fundamental for both understanding the epidemiology of the Diseases and for targeted vector control. In the absence of classical morphological characters unambiguously identifying the species, DNA sequence-based tests have been established for the distinction of selected species in some parts of Europe. Since specificity and sensitivity of these tests have been shown to be in need of improvement, an alternative PCR assay targeting the mitochondrial cytochrome oxidase subunit I (COI) gene was developed for the identification of the three Obsoletus complex species endemic to Germany ( C. obsoletus , C. scoticus , C. chiopterus ) plus the isomorphic species C. dewulfi . Methods Biting midges of the genus Culicoides caught by UV light traps all over Germany were morphologically pre-identified to species or complex level. The COI region was amplified from their extracted DNA and sequenced. Final species assignment was done by sequence comparison to GenBank entries and to morphologically identified males. Species-specific consensus sequences were aligned and polymorphisms were utilized to design species-specific primers to PCR-identify specimens when combined with a universal primer. Results The newly developed multiplex PCR assay was successfully tested on genetically defined Obsoletus complex material as well as on morphologically pre-identified field material. The intended major advantage of the assay as compared to other PCR approaches, namely the production of only one single characteristic band for each species, could be realized with high specificity and sensitivity. Conclusion To elucidate the biological characteristics of potential vectors of Disease agents, such as ecology, behaviour and vector competence, and the role of these haematophagous arthropods in the epidemiology of the Diseases, simple, cost-effective and, most importantly, reliable identification techniques are necessary. The PCR assay presented will help to identify culicoid vector species and therefore add to Bluetongue and Schmallenberg Disease research including vector control and monitoring.
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Bluetongue Disease an analysis of the epidemic in germany 2006 2009
Arthropods as Vectors of Emerging Diseases, 2012Co-Authors: Franz Josef Conraths, Jörn Gethmann, Carolina Probst, Michael Eschbaumer, Conrad M Freuling, Bernd Hoffmann, Matthias Kramer, Christoph Staubach, Martin BeerAbstract:In August 2006, Bluetongue virus of serotype 8 (BTV-8), which had occurred before in the sub-Saharan region, Asia and South America, was introduced into Central Europe. The virus hit an area with a high population density of BTV-naive ruminants, suitable vectors (Culicoides spp.) and climatic conditions favourable for virogenesis and transmission. In 2006 and 2007, the Disease spread over wide parts of western Germany and had a high economic impact on sheep and cattle farms. To reduce animal losses, mitigate the clinical symptoms and stop the further spread of the Disease, Germany decided to implement a compulsory vaccination programme with a monovalent, inactivated vaccine against BTV-8 in May 2008 which has apparently led to the eradication of the Disease. This chapter reviews the pathogenesis of Bluetongue Disease, the clinical signs, diagnosis, the course of the epidemic, control measures and the economic impact of the BTV-8 epidemic in Germany.
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a review of rt pcr technologies used in veterinary virology and Disease control sensitive and specific diagnosis of five livestock Diseases notifiable to the world organisation for animal health
Veterinary Microbiology, 2009Co-Authors: Bernd Hoffmann, Peter P. C. Mertens, Martin Beer, Scott M Reid, C A L Oura, Piet A Van Rijn, Marek J Slomka, J Banks, Ian H Brown, D J AlexanderAbstract:Real-time, reverse transcription polymerase chain reaction (rRT-PCR) has become one of the most widely used methods in the field of molecular diagnostics and research. The potential of this format to provide sensitive, specific and swift detection and quantification of viral RNAs has made it an indispensable tool for state-of-the-art diagnostics of important human and animal viral pathogens. Integration of these assays into automated liquid handling platforms for nucleic acid extraction increases the rate and standardisation of sample throughput and decreases the potential for cross-contamination. The reliability of these assays can be further enhanced by using internal controls to validate test results. Based on these advantageous characteristics, numerous robust rRT-PCRs systems have been developed and validated for important epizootic Diseases of livestock. Here, we review the rRT-PCR assays that have been developed for the detection of five RNA viruses that cause Diseases that are notifiable to the World Organisation for Animal Health (OIE), namely: foot-and-mouth Disease, classical swine fever, Bluetongue Disease, avian influenza and Newcastle Disease. The performance of these tests for viral diagnostics and Disease control and prospects for improved strategies in the future are discussed.
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First occurrence of Culicoides obsoletus-transmitted Bluetongue virus epidemic in Central Europe
Parasitology Research, 2007Co-Authors: Heinz Mehlhorn, Bernd Hoffmann, Volker Walldorf, Sven Klimpel, Birgit Jahn, Friedhelm Jaeger, Josef Eschweiler, Martin BeerAbstract:In August 2006, Bluetongue virus Disease (BTD) was detected for the first time in the Netherlands, Belgium, Germany and Northern France. Serological tests as well as reverse transcriptase polymerase chain reaction (RT-PCR) proved the occurrence of Bluetongue virus (BTV) in Diseased sheep and cattle, and the virus was identified as serotype 8. Therefore, the search for possible vectors was immediately initiated in the outbreak region in Germany. Traps with automatically regulated ultraviolet light lamps were placed at two different farms with sero-positive cattle, and insect monitoring was done from August 2006 until January 2007. The caught arthropods were weekly determined, and it could be observed that midges of the dipteran family Ceratopogonidae occurred in large numbers, sometimes representing up to 40% of all individuals. The microscopical analysis of the wing morphology showed that the species (complex) Culicoides obsoletus was most abundant covering about 97% of the analysed midges. On the second place ranged C. pulicaris , while C. nubeculosus and C. festivipennis were found only as single individuals. Fed and unfed females were separated, sent to the National Reference Laboratory for Bluetongue Disease (Friedrich-Loeffler-Institut, Isle of Riems, Germany) and investigated with a BTV-8-specific real-time RT-PCR. It could be demonstrated that at both farms both fed and unfed C. obsoletus were tested positive for BTV-8 genomes, while none of the other species scored positive. This finding strongly supports that the BTD-epidemic, which reached in the meantime wide regions of North Rhine–Westphalia in Germany and of the neighbouring countries with several hundreds of affected farms, is initiated by virus transmission during the blood meal of midges of the C. obsoletus complex. Since they were captured still at the 21st of December close to cattle with clinical signs, it must be feared that BTV-8 is now established in Central Europe, where it had been absent until now.
Martinezde J La Puente - One of the best experts on this subject based on the ideXlab platform.
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first molecular identification of the vertebrate hosts of culicoides imicola in europe and a review of its blood feeding patterns worldwide implications for the transmission of Bluetongue Disease and african horse sickness
Medical and Veterinary Entomology, 2017Co-Authors: Martinezde J La Puente, Javier Navarro, Martina Ferraguti, Ramon C Soriguer, Jordi FiguerolaAbstract:Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause Bluetongue Disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.