Bluetongue virus detection in new Culicoides species in Sardinia, Italy

2019 ◽  
Vol 184 (20) ◽  
pp. 621-621 ◽  
Author(s):  
Cipriano Foxi ◽  
Giorgio Meloni ◽  
Giantonella Puggioni ◽  
Daniela Manunta ◽  
Angelamaria Rocchigiani ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Vector Competence ◽  
Virus Detection ◽  
Culicoides Species ◽  
Rt Pcr ◽  
Biting Midges ◽  
Body Regions ◽  
Culicoides Imicola ◽  
Obsoletus Complex ◽  
The Mediterranean Basin

Bluetongue is an infectious disease transmitted by Culicoides biting midges. Culicoides imicola is considered the main vector in the Mediterranean basin but other species have been implicated in the Bluetongue virus (BTV) transmission. During 2017, BTV serotype 4 re-occurred in Sardinia causing outbreaks in sheep farms. A survey was carried out on affected farms with the aim to detect the virus in field-collected Culicoides. Biting midges were morphologically identified, pooled and then assayed with a real time RT-PCR. To evaluate BTV dissemination, some Culicoides were dissected and head, thorax and abdomen were tested singly by PCR. A total of 173,738 Culicoides adults were collected. Viral RNA was detected in 68 out of 77 pools and all species analysed resulted positive. Detection of BTV in parous female body regions (head, thorax and abdomen) confirmed the full dissemination of BTV in all species analysed. During this study, the vector competence of C imicola, C newsteadi s.l. and Obsoletus complex was confirmed. The authors found two new Culicoides species BTV positive, C paolae never associated with BTV transmission and C circumscriptus only recently found BTV positive in Turkey, which could be considered potential vectors.

scholarly journals Vector Competence of Italian Populations of Culicoides for Some Bluetongue Virus Strains Responsible for Recent Northern African and European Outbreaks

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 941 ◽  
Author(s):  
Valentina Federici ◽  
Maria Goffredo ◽  
Giuseppe Mancini ◽  
Michela Quaglia ◽  
Adriana Santilli ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Vector Competence ◽  
Oral Infection ◽  
Balearic Islands ◽  
Rt Pcr ◽  
Vector Species ◽  
Vaccination Programs ◽  
Culicoides Obsoletus ◽  
Culicoides Imicola ◽  
Virus Strains

The distribution of Bluetongue virus (BTV) in Europe can be represented by two distinct and interconnected epidemiological systems (episystems), each characterized by different ecological characteristics and vector species. This study investigated the vector competence of Italian populations of Culicoides imicola and Culicoides obsoletus/scoticus to some representative BTV strains after artificial oral infection. The BTV strains were selected according to their ability to spread to one or both episystems and included BTV-4 ITA, responsible of the recent Italian and French BTV-4 outbreaks; the BTV-2 strain which caused the first BTV incursion in Italy, Corsica, and Balearic Islands; BTV-4 MOR, responsible for the epidemic in Morocco; and BTV-8, the strain which spread through Europe between 2006 and 2008. Blood-soaked cotton pledgets and Hemotek membrane feeder using Parafilm® membrane were used to artificially feed midges. For each population/strain, recovery rates (positive/tested heads) were evaluated using serogroup- and serotype-specific RT-PCR. The trial demonstrated that, except for the Abruzzo population of C. obsoletus/C. scoticus, which was refractory to BTV-4 MOR infection, all the investigated Culicoides populations are susceptible to the selected BTV strains and that, if prompt vaccination programs and restriction measures had not been implemented, BTV-2 and BTV-4 MOR could have spread all over Europe.

scholarly journals Culicoides biting midges at the National Zoological Gardens of South Africa : research communication

2007 ◽  
Vol 74 (4) ◽  
Author(s):  
K. Labuschagne ◽  
L.J. Gerber ◽  
I. Espie ◽  
S. Carpenter
Keyword(s):  
South Africa ◽  
Vector Competence ◽  
Far East ◽  
Wild Animals ◽  
Light Traps ◽  
Biting Midges ◽  
Research Communication ◽  
Culicoides Imicola ◽  
Large Numbers ◽  
Culicoides Biting Midges

Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.

scholarly journals Measurement of the Infection and Dissemination of Bluetongue Virus in Culicoides Biting Midges Using a Semi-Quantitative RT-PCR Assay and Isolation of Infectious Virus

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e70800 ◽  
Author(s):  
Eva Veronesi ◽  
Frank Antony ◽  
Simon Gubbins ◽  
Nick Golding ◽  
Alison Blackwell ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Infectious Virus ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Biting Midges ◽  
Culicoides Biting Midges

scholarly journals Synthèse des études sur la compétence vectorielle en Europe : que savons-nous ? que reste-t-il à apprendre ?

2009 ◽  
Vol 62 (2-4) ◽  
pp. 106
Author(s):  
Simon Carpenter
Keyword(s):  
Virus Isolation ◽  
Disease Risk ◽  
Vector Competence ◽  
Integrated Control ◽  
Virus Detection ◽  
Control Measures ◽  
Correct Identification ◽  
Culicoides Species ◽  
Feeding Rates ◽  
Recent Trial

The correct identification of all potential vectors of bluetongue virus (BTV) is crucial for the implementation of integrated control measures, disease risk analysis and management of this disease. The collection of Culicoides midges and virus isolation from the captured midges will give an indication of what Culicoides species may be involved in the transmission of the virus. The number of midges collected with light traps will give an indica­tion of the risk of the virus spreading in the area.  Reliable detection of BTV from field-collected vectors is dif­ficult due to several constraints related to the vector itself and to laboratory procedures. A clear recommendation will be to maximise insect collections after viraemias are detected in mam­mals. Where possible, captured individuals should be identified to species level and populations’ age graded. Virus detection in the collected midges is conducted by using molecular tech­niques [e.g. polymerase chain reaction (PCR)], and virus isola­tion is performed using either embryonated chicken eggs or cell cultures. Positive results from either pools or individuals have different meanings in terms of vector competence and need to be evaluated with care. Individually analysed parous midges from which virus could be isolated indicate that the insect has fed on a viraemic host. It does, however, not show that the virus has replicated in the vector and that transmission could be related to that species.  Current laboratory techniques for measuring vector competence have several drawbacks, e.g. low blood feeding rates (especially so for European Culicoides species), the small size of Culicoides species involved, and the limited availability of laboratory colo­nies of European Culicoides species. Some techniques, as for example multiplex PCR, have increased the number of sam­ples which can be processed in one day (up to 800 insects). A recent trial, with field-collected Culicoides fed and incubated in the laboratory, showed transmissible infection levels in C. scoticus for BTV-9 and 8 similar to that reported from the field. Future needs in this field are the evaluation of cell types, e.g. Culicoides cell lines for virus isolation, detection of the virus in the saliva of Culicoides, the development of a reference colony (i.e. C. sonorensis), the sequencing of its genome, as well as the standardisation of experimental procedures run across wide geographic areas.

scholarly journals Post-epidemic Occurrence of Bluetongue Virus Vectors (Culicoides Species) în Iași County

2020 ◽  
Vol 77 (2) ◽  
pp. 160
Author(s):  
Dragoș Constantin ANIȚĂ ◽  
Ioana Mădălina POPESCU ◽  
Ștefania ANDERCO ◽  
Luanda Elena OȘLOBANU ◽  
Adriana ANIȚĂ ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
First Year ◽  
Biting Midges ◽  
Culicoides Obsoletus ◽  
The Family ◽  
Veterinary Importance ◽  
Culicoides Nubeculosus ◽  
Second Year ◽  
Culicoides Vectors ◽  
Obsoletus Complex

Culicoides is a genus of biting midges in the family Ceratopogonidae, representing a big threat, giving that several species serve as biological vectors of pathogens of veterinary importance. BTV distribution and persistence is thought to be almost entirely dependent upon the presence or absence of Culicoides adults vector. In this study, biting midges were collected during 2015-2016, once a week, from April to December. In the first year, 2617 BTV vector specimens were collected and identified as Culicoides obsoletus (41.2%; 95% CI: 39-43), Culicoides pulicaris (58%; 95% CI: 56-59) and Culicoides nubeculosus (0.8%; 95% CI: 0.4-1.1). In the second year, 165 BTV vector specimens were collected and identified as Culicoides obsoletus (44.25%; 95% CI: 36-51), Culicoides pulicaris (50.3%; 95% CI: 42-57), Culicoides dewulfi (4.84%; 95% CI: 1.5-8.1) and Culicoides nubeculosus (0.61%; 95% CI: 0.5-1.7). Culicoides pulicaris and Culicoides obsoletus complex were especially abundant within the two collection sites in Iași County. Our data on post-epidemic occurrence and composition of BTV vector species in the studied area will facilitate a better understanding of Culicoides vectors distribution and the possible role in bluetongue virus overwintering.

scholarly journals The genome of the biting midge Culicoides sonorensis and gene expression analyses of vector competence for Bluetongue virus

2018 ◽  
Author(s):  
Ramiro Morales-Hojas ◽  
Malcolm Hinsley ◽  
Irina M. Armean ◽  
Rhiannon Silk ◽  
Lara E. Harrup ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bluetongue Virus ◽  
Reference Genome ◽  
Vector Competence ◽  
Expression Profiles ◽  
Yield Potential ◽  
Future Research ◽  
Biting Midges ◽  
Culicoides Sonorensis ◽  
Gene Expression Analyses

AbstractBackgroundThe use of the new genomic technologies has led to major advances in control of several arboviruses of medical importance such as Dengue. However, the development of tools and resources available for vectors of non-zoonotic arboviruses remains neglected. Biting midges of the genus Culicoides transmit some of the most important arboviruses of wildlife and livestock worldwide, with a global impact on economic productivity, health and welfare. The absence of a suitable reference genome has hindered genomic analyses to date in this important genus of vectors. In the present study, the genome of Culicoides sonorensis, a vector of bluetongue virus (BTV) in the USA, has been sequenced to provide the first reference genome for these vectors. In this study, we also report the use of the reference genome to perform initial transcriptomic analyses of vector competence for BTV.ResultsOur analyses reveal that the genome is 197.4 Mb, assembled in 7,974 scaffolds. Its annotation using the transcriptomic data generated in this study and in a previous study has identified 15,629 genes. Gene expression analyses of C. sonorensis females infected with BTV performed in this study revealed 165 genes that were differentially expressed between vector competent and refractory females. Two candidate genes, glutathione S-transferase (gst) and the antiviral helicase ski2, previously recognized as involved in vector competence for BTV in C. sonorensis (gst) and repressing dsRNA virus propagation (ski2), were confirmed in this study.ConclusionsThe reference genome of C. sonorensis has enabled preliminary analyses of the gene expression profiles of vector competent and refractory individuals. The genome and transcriptomes generated in this study provide suitable tools for future research on arbovirus transmission. These provide a significant resource for these vector lineage, which diverged from other major Dipteran vector families over 200 million years ago. The genome will be a valuable source of comparative data for other important Dipteran vector families including mosquitoes (Culicidae) and sandflies (Psychodidae), and yield potential targets for transgenic modification in vector control and functional studies.

scholarly journals Environmental Drivers of Adult Seasonality and Abundance of Biting Midges Culicoides (Diptera: Ceratopogonidae), Bluetongue Vector Species in Spain

2020 ◽  
Author(s):  
Carlos Barceló ◽  
Bethan V Purse ◽  
Rosa Estrada ◽  
Javier Lucientes ◽  
Miguel Á Miranda ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Viral Disease ◽  
High Abundance ◽  
Environmental Drivers ◽  
Biting Midges ◽  
Complex Species ◽  
Domestic Ruminants ◽  
Culicoides Imicola ◽  
Obsoletus Complex

Abstract Bluetongue is a viral disease affecting wild and domestic ruminants transmitted by several species of biting midges Culicoides Latreille. The phenology of these insects were analyzed in relation to potential environmental drivers. Data from 329 sites in Spain were analyzed using Bayesian Generalized Linear Mixed Model (GLMM) approaches. The effects of environmental factors on adult female seasonality were contrasted. Obsoletus complex species (Diptera: Ceratopogonidae) were the most prevalent across sites, followed by Culicoides newsteadi Austen (Diptera: Ceratopogonidae). Activity of female Obsoletus complex species was longest in sites at low elevation, with warmer spring average temperatures and precipitation, as well as in sites with high abundance of cattle. The length of the Culicoides imicola Kieffer (Diptera: Ceratopogonidae) female adult season was also longest in sites at low elevation with higher coverage of broad-leaved vegetation. Long adult seasons of C. newsteadi were found in sites with warmer autumns and higher precipitation, high abundance of sheep. Culicoides pulicaris (Linnaeus) (Diptera: Ceratopogonidae) had longer adult periods in sites with a greater number of accumulated degree days over 10°C during winter. These results demonstrate the eco-climatic and seasonal differences among these four taxa in Spain, which may contribute to determining sites with suitable environmental circumstances for each particular species to inform assessments of the risk of Bluetongue virus outbreaks in this region.

Bluetongue Virus Detection by Real-Time RT-PCR inCulicoidesCaptured During the 2006 Epizootic in Belgium and Development of an Internal Control

2009 ◽  
Vol 56 (5) ◽  
pp. 170-177 ◽  
Author(s):  
T. Vanbinst ◽  
F. Vandenbussche ◽  
E. Vandemeulebroucke ◽  
I. De Leeuw ◽  
I. Deblauwe ◽  
...  
Keyword(s):  
Real Time ◽  
Internal Control ◽  
Bluetongue Virus ◽  
Virus Detection ◽  
Rt Pcr
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