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Bock S, Hoffmann B, Beer M, Wernike K. Saving Resources: SARS-CoV-2 Diagnostics by Real-Time RT-PCR Using Reduced Reaction Volumes. Diseases 2021; 9:84. [PMID: 34842648 PMCID: PMC8628695 DOI: 10.3390/diseases9040084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/04/2021] [Accepted: 11/11/2021] [Indexed: 01/12/2023] Open
Abstract
Since the beginning of 2020, the betacoronavirus SARS-CoV-2 is causing a global pandemic of an acute respiratory disease termed COVID-19. The diagnostics of the novel disease is primarily based on direct virus detection by RT-PCR; however, the availability of test kits may become a major bottleneck, when millions of tests are performed per week. To increase the flexibility of SARS-CoV-2 diagnostics, three real-time RT-PCR assays listed on the homepage of the World Health Organization were selected and investigated regarding their compatibility with three different RT-PCR kits. Furthermore, the reaction volume of the PCR chemistry was reduced up to half of the original protocol to make the individual reactions more cost- and resource-effective. When testing dilution series of culture-grown virus, nearly identical quantification cycle values (Cq) were obtained for all RT-PCR assay/chemistry combinations. Regarding the SARS-CoV-2 detection in clinical samples, agreeing results were obtained for all combinations for virus negative specimens and swabs containing high to medium viral genome loads. In cases of very low SARS-CoV-2 genome loads (Cq > 36), inconsistent results were observed, with some test runs scoring negative and some positive. However, no preference of a specific target within the viral genome (E, RdRp, or N) or of a certain chemistry was seen. In summary, a reduction of the reaction volume and the type of PCR chemistry did not influence the PCR sensitivity.
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Affiliation(s)
- Sabine Bock
- Berlin-Brandenburg State Laboratory, 15236 Frankfurt, Germany;
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany; (B.H.); (M.B.)
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany; (B.H.); (M.B.)
| | - Kerstin Wernike
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany; (B.H.); (M.B.)
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Ropiak HM, King S, Busquets MG, Newbrook K, Pullinger GD, Brown H, Flannery J, Gubbins S, Batten C, Rajko-Nenow P, Darpel KE. Identification of a BTV-Strain-Specific Single Gene That Increases Culicoides Vector Infection Rate. Viruses 2021; 13:1781. [PMID: 34578362 PMCID: PMC8472919 DOI: 10.3390/v13091781] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/27/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022] Open
Abstract
Since the 2000s, the distribution of bluetongue virus (BTV) has changed, leading to numerous epidemics and economic losses in Europe. Previously, we found a BTV-4 field strain with a higher infection rate of a Culicoides vector than a BTV-1 field strain has. We reverse-engineered parental BTV-1 and BTV-4 strains and created BTV-1/BTV-4 reassortants to elucidate the influence of individual BTV segments on BTV replication in both C. sonorensis midges and in KC cells. Substitution of segment 2 (Seg-2) with Seg-2 from the rBTV-4 significantly increased vector infection rate in reassortant BTV-14S2 (30.4%) in comparison to reverse-engineered rBTV-1 (1.0%). Replacement of Seg-2, Seg-6 and Seg-7 with those from rBTV-1 in reassortant BTV-41S2S6S7 (2.9%) decreased vector infection rate in comparison to rBTV-4 (30.2%). However, triple-reassorted BTV-14S2S6S7 only replicated to comparatively low levels (3.0%), despite containing Seg-2, Seg-6 and Seg-7 from rBTV-4, indicating that vector infection rate is influenced by interactions of multiple segments and/or host-mediated amino acid substitutions within segments. Overall, these results demonstrated that we could utilize reverse-engineered viruses to identify the genetic basis influencing BTV replication within Culicoides vectors. However, BTV replication dynamics in KC cells were not suitable for predicting the replication ability of these virus strains in Culicoides midges.
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Grace KEF, Papadopoulou C, Floyd T, Avigad R, Collins S, White E, Batten C, Flannery J, Gubbins S, Carpenter ST. Risk-based surveillance for bluetongue virus in cattle on the south coast of England in 2017 and 2018. Vet Rec 2020; 187:e96. [PMID: 32917835 PMCID: PMC7786256 DOI: 10.1136/vr.106016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/01/2020] [Accepted: 07/13/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Bluetongue (BT) is a viral disease of ruminants and camelids which can have a significant impact on animal health and welfare and cause severe economic loss. The UK has been officially free of bluetongue virus (BTV) since 2011. In 2015, BTV-8 re-emerged in France and since then BTV has been spreading throughout Europe. In response to this outbreak, risk-based active surveillance was carried out at the end of the vector seasons in 2017 and 2018 to assess the risk of incursion of BTV into Great Britain. METHOD Atmospheric dispersion modelling identified counties on the south coast of England at higher risk of an incursion. Blood samples were collected from cattle in five counties based on a sample size designed to detect at least one positive if the prevalence was 5 per cent or greater, with 95 per cent confidence. RESULTS No virus was detected in the 478 samples collected from 32 farms at the end of the 2017 vector season or in the 646 samples collected from 43 farms at the end of the 2018 vector season, when tested by RT-qPCR. CONCLUSION The negative results from this risk-based survey provided evidence to support the continuation of the UK's official BTV-free status.
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Affiliation(s)
| | | | - Tobias Floyd
- Pathology, Animal and Plant Health Agency, Addlestone, UK
| | - Rachelle Avigad
- Department of Epidemiological Sciences, APHA, Addlestone, UK
| | - Steve Collins
- Information Management and Technology, APHA, Worcester, UK
| | | | - Carrie Batten
- The Non-Vesicular Reference Laboratories, Pirbright Institute, Pirbright, Surrey, UK
| | - John Flannery
- The Non-Vesicular Reference Laboratories, Pirbright Institute, Pirbright, Surrey, UK
| | - Simon Gubbins
- Transmission Biology, The Pirbright Institute, Pirbright, Surrey, UK
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Ashby M, Rajko-Nenow P, Batten C, Flannery J. Simultaneous Detection of Bluetongue Virus Serotypes Using xMAP Technology. Microorganisms 2020; 8:microorganisms8101564. [PMID: 33050655 PMCID: PMC7650804 DOI: 10.3390/microorganisms8101564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 12/27/2022] Open
Abstract
Bluetongue is an economically important disease of ruminants caused by the bluetongue virus (BTV). BTV is serologically diverse, which complicates vaccination strategies. Rapid identification of the causative BTV serotypes is critical, however, real-time PCR (RT-qPCR) can be costly and time consuming to perform when the circulating serotypes are unknown. The Luminex xMAP technology is a high-throughput platform that uses fluorescent beads to detect multiple targets simultaneously. We utilized existing BTV serotyping RT-qPCR assays for BTV-1 to BTV-24 and adapted them for use with the xMAP platform. The xMAP assay specifically detected all 24 BTV serotypes when testing reference strains. In all BTV-positive samples, the sensitivity of the BTV xMAP was 87.55% whereas the sensitivity of the serotype-specific RT-qPCR was 79.85%. The BTV xMAP assay allowed for the specific detection of BTV serotypes 1-24 at a lower cost than current RT-qPCR assays. Overall, the assay provides a useful novel diagnostic tool, particularly when analyzing large sample sets. The use of the BTV xMAP assay will allow for the rapid assessment of BTV epidemiology and may inform decision-making related to control and prevention measures.
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Chambaro HM, Sasaki M, Simulundu E, Silwamba I, Sinkala Y, Gonzalez G, Squarre D, Fandamu P, Lubaba CH, Munyeme M, Maseko A, Chimvwele C, Mataa L, Mooya LE, Mukubesa AN, Harima H, Samui KL, Munang’andu HM, Simuunza M, Nalubamba KS, Qiu Y, Carr MJ, Hall WW, Eshita Y, Sawa H, Orba Y. Co-Circulation of Multiple Serotypes of Bluetongue Virus in Zambia. Viruses 2020; 12:v12090963. [PMID: 32878170 PMCID: PMC7552058 DOI: 10.3390/v12090963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 11/16/2022] Open
Abstract
Bluetongue (BT) is an arthropod-borne viral disease of ruminants with serious trade and socio-economic implications. Although the disease has been reported in a number of countries in sub-Saharan Africa, there is currently no information on circulating serotypes and disease distribution in Zambia. Following surveillance for BT in domestic and wild ruminants in Zambia, BT virus (BTV) nucleic acid and antibodies were detected in eight of the 10 provinces of the country. About 40% (87/215) of pooled blood samples from cattle and goats were positive for BTV nucleic acid, while one hartebeest pool (1/43) was positive among wildlife samples. Sequence analysis of segment 2 revealed presence of serotypes 3, 5, 7, 12 and 15, with five nucleotypes (B, E, F, G and J) being identified. Segment 10 phylogeny showed Zambian BTV sequences clustering with Western topotype strains from South Africa, intimating likely transboundary spread of BTV in Southern Africa. Interestingly, two Zambian viruses and one isolate from Israel formed a novel clade, which we designated as Western topotype 4. The high seroprevalence (96.2%) in cattle from Lusaka and Central provinces and co-circulation of multiple serotypes showed that BT is widespread, underscoring the need for prevention and control strategies.
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Affiliation(s)
- Herman M. Chambaro
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- Virology Unit, Central Veterinary Research Institute, Lusaka 10101, Zambia;
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
| | - Michihito Sasaki
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
| | - Edgar Simulundu
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
- Macha Research Trust, Choma 10101, Zambia
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
| | - Isaac Silwamba
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Yona Sinkala
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Gabriel Gonzalez
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
| | - David Squarre
- The University of Edinburgh, Edinburgh EH25 9RG, Scotland, UK;
- Department of National Parks and Wildlife, Chilanga 10101, Zambia
| | - Paul Fandamu
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Caesar H. Lubaba
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Musso Munyeme
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Alikhadio Maseko
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Choopa Chimvwele
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Liywalii Mataa
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Lynnfield E. Mooya
- Virology Unit, Central Veterinary Research Institute, Lusaka 10101, Zambia;
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Andrew N. Mukubesa
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Hayato Harima
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
| | - Kenny L. Samui
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Hetron M. Munang’andu
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, 0454 Oslo, Norway;
| | - Martin Simuunza
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - King S. Nalubamba
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Yongjin Qiu
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka 10101, Zambia; (Y.Q.); (Y.E.)
| | - Michael J. Carr
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
| | - William W. Hall
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Global Virus Network, Baltimore, MD 21201, USA
| | - Yuki Eshita
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka 10101, Zambia; (Y.Q.); (Y.E.)
| | - Hirofumi Sawa
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Global Virus Network, Baltimore, MD 21201, USA
| | - Yasuko Orba
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
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Flannery J, Frost L, Fay P, Hicks H, Henstock M, Smreczak M, Orłowska A, Rajko-Nenow P, Darpel K, Batten C. BTV-14 Infection in Sheep Elicits Viraemia with Mild Clinical Symptoms. Microorganisms 2020; 8:E892. [PMID: 32545731 PMCID: PMC7355590 DOI: 10.3390/microorganisms8060892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 11/16/2022] Open
Abstract
In 2011, Bluetongue virus serotype 14 (BTV-14) was detected in Russia during routine surveillance, and was subsequently found in a number of European countries. The strain had high sequence similarity to a BTV-14 vaccine strain. We aimed to determine the risk of this BTV-14 strain causing disease in a UK sheep breed. Four Poll Dorset sheep were infected with a Polish isolate of BTV-14 and infection kinetics were monitored over 28 days. BTV RNA was detected in EDTA blood by 4 days post-infection (dpi) and remained detectable at 28 days post-infection (dpi). Peak viraemia occurred at 6 and 7 dpi with Ct values ranging between 24.6 and 27.3 in all infected animals. BTV antibodies were detected by 10 dpi using a commercial ELISA and neutralising antibodies were detected from 10 dpi. BTV was isolated between 6 and 12 dpi. All infected sheep developed mild clinical signs such as reddening of conjunctiva and mucosal membranes, with one sheep demonstrating more overt clinical signs. Two uninoculated control animals remained clinically healthy and did not have detectable BTV RNA or antibodies. The overall mild clinical symptoms caused by this BTV-14 in this highly susceptible sheep breed were in accordance with the asymptomatic infections observed in the affected countries.
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Affiliation(s)
- John Flannery
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Lorraine Frost
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Petra Fay
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Hayley Hicks
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Mark Henstock
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Marcin Smreczak
- Department of Virology, National Veterinary Research Institute, 24-100 Puławy, Poland; (M.S.); (A.O.)
| | - Anna Orłowska
- Department of Virology, National Veterinary Research Institute, 24-100 Puławy, Poland; (M.S.); (A.O.)
| | - Paulina Rajko-Nenow
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Karin Darpel
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
| | - Carrie Batten
- Non-Vesicular Reference Laboratories, The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK; (L.F.); (P.F.); (H.H.); (M.H.); (P.R.-N.); (K.D.); (C.B.)
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Korotkyi O, Dvorshchenko K, Vovk A, Dranitsina A, Tymoshenko M, Kot L, Ostapchenko L. Effect of probiotic composition on oxidative/antioxidant balance in blood of rats under experimental osteoarthriti. UKRAINIAN BIOCHEMICAL JOURNAL 2019. [DOI: 10.15407/ubj91.06.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Flannery J, Sanz-Bernardo B, Ashby M, Brown H, Carpenter S, Cooke L, Corla A, Frost L, Gubbins S, Hicks H, Qureshi M, Rajko-Nenow P, Sanders C, Tully M, Bréard E, Sailleau C, Zientara S, Darpel K, Batten C. Evidence of reduced viremia, pathogenicity and vector competence in a re-emerging European strain of bluetongue virus serotype 8 in sheep. Transbound Emerg Dis 2019; 66:1177-1185. [PMID: 30661301 PMCID: PMC6563110 DOI: 10.1111/tbed.13131] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/01/2018] [Accepted: 01/13/2019] [Indexed: 12/02/2022]
Abstract
The outbreak of bluetongue virus (BTV) serotype 8 (BTV-8) during 2006-2009 in Europe was the most costly epidemic of the virus in recorded history. In 2015, a BTV-8 strain re-emerged in France which has continued to circulate since then. To examine anecdotal reports of reduced pathogenicity and transmission efficiency, we investigated the infection kinetics of a 2007 UK BTV-8 strain alongside the re-emerging BTV-8 strain isolated from France in 2017. Two groups of eight BTV-naïve British mule sheep were inoculated with 5.75 log10 TCID50 /ml of either BTV-8 strain. BTV RNA was detected by 2 dpi in both groups with peak viraemia occurring between 5-9 dpi. A significantly greater amount of BTV RNA was detected in sheep infected with the 2007 strain (6.0-8.8 log10 genome copies/ml) than the re-emerging BTV-8 strain (2.9-7.9 log10 genome copies/ml). All infected sheep developed BTV-specific antibodies by 9 dpi. BTV was isolated from 2 dpi to 12 dpi for 2007 BTV-8-inoculated sheep and from 5 to 10 dpi for sheep inoculated with the remerging BTV-8. In Culicoides sonorensis feeding on the sheep over the period 7-12 dpi, vector competence was significantly higher for the 2007 strain than the re-emerging strain. Both the proportion of animals showing moderate (as opposed to mild or no) clinical disease (6/8 vs. 1/8) and the overall clinical scores (median 5.25 vs. 3) were significantly higher in sheep infected with the 2007 strain, compared to those infected with the re-emerging strain. However, one sheep infected with the re-emerging strain was euthanized at 16 dpi having developed severe lameness. This highlights the potential of the re-emerging BTV-8 to still cause illness in naïve ruminants with concurrent costs to the livestock industry.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Emmanuel Bréard
- Université Paris-Est ANSES Alfort, UMR 1161 ANSES/INRA/ENVA,, Maisons-Alfort, France
| | - Corinne Sailleau
- Université Paris-Est ANSES Alfort, UMR 1161 ANSES/INRA/ENVA,, Maisons-Alfort, France
| | - Stephan Zientara
- Université Paris-Est ANSES Alfort, UMR 1161 ANSES/INRA/ENVA,, Maisons-Alfort, France
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