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Douglass N, Omar R, Munyanduki H, Suzuki A, de Moor W, Mutowembwa P, Pretorius A, Nefefe T, van Schalkwyk A, Kara P, Heath L, Williamson AL. The Development of Dual Vaccines against Lumpy Skin Disease (LSD) and Bovine Ephemeral Fever (BEF). Vaccines (Basel) 2021; 9:vaccines9111215. [PMID: 34835146 PMCID: PMC8621795 DOI: 10.3390/vaccines9111215] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 12/21/2022] Open
Abstract
Dual vaccines (n = 6) against both lumpy skin disease (LSD) and bovine ephemeral fever (BEF) were constructed, based on the BEFV glycoprotein (G) gene, with or without the BEFV matrix (M) protein gene, inserted into one of two different LSDV backbones, nLSDV∆SOD-UCT or nLSDVSODis-UCT. The inserted gene cassettes were confirmed by PCR; and BEFV protein was shown to be expressed by immunofluorescence. The candidate dual vaccines were initially tested in a rabbit model; neutralization assays using the South African BEFV vaccine (B-Phemeral) strain showed an African consensus G protein gene (Gb) to give superior neutralization compared to the Australian (Ga) gene. The two LSDV backbones expressing both Gb and M BEFV genes were tested in cattle and shown to elicit neutralizing responses to LSDV as well as BEFV after two inoculations 4 weeks apart. The vaccines were safe in cattle and all vaccinated animals were protected against virulent LSDV challenge, unlike a group of control naïve animals, which developed clinical LSD. Both neutralizing and T cell responses to LSDV were stimulated upon challenge. After two inoculations, all vaccinated animals produced BEFV neutralizing antibodies ≥ 1/20, which is considered protective for BEF.
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Affiliation(s)
- Nicola Douglass
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
- Correspondence: ; Tel.: +27-832-310-553
| | - Ruzaiq Omar
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
| | - Henry Munyanduki
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
| | - Akiko Suzuki
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
| | - Warren de Moor
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
| | - Paidamwoyo Mutowembwa
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Alri Pretorius
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Tshifhiwa Nefefe
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Antoinette van Schalkwyk
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Pravesh Kara
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Livio Heath
- Onderstepoort Veterinary Institute, ARC, Pretoria 0110, South Africa; (P.M.); (A.P.); (T.N.); (A.v.S.); (P.K.); (L.H.)
| | - Anna-Lise Williamson
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (R.O.); (H.M.); (A.S.); (W.d.M.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
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Clemmons EA, Alfson KJ, Dutton JW. Transboundary Animal Diseases, an Overview of 17 Diseases with Potential for Global Spread and Serious Consequences. Animals (Basel) 2021; 11:2039. [PMID: 34359167 PMCID: PMC8300273 DOI: 10.3390/ani11072039] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 12/21/2022] Open
Abstract
Animals provide food and other critical resources to most of the global population. As such, diseases of animals can cause dire consequences, especially disease with high rates of morbidity or mortality. Transboundary animal diseases (TADs) are highly contagious or transmissible, epidemic diseases, with the potential to spread rapidly across the globe and the potential to cause substantial socioeconomic and public health consequences. Transboundary animal diseases can threaten the global food supply, reduce the availability of non-food animal products, or cause the loss of human productivity or life. Further, TADs result in socioeconomic consequences from costs of control or preventative measures, and from trade restrictions. A greater understanding of the transmission, spread, and pathogenesis of these diseases is required. Further work is also needed to improve the efficacy and cost of both diagnostics and vaccines. This review aims to give a broad overview of 17 TADs, providing researchers and veterinarians with a current, succinct resource of salient details regarding these significant diseases. For each disease, we provide a synopsis of the disease and its status, species and geographic areas affected, a summary of in vitro or in vivo research models, and when available, information regarding prevention or treatment.
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Affiliation(s)
- Elizabeth A. Clemmons
- Southwest National Primate Research Center, Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA;
| | - Kendra J. Alfson
- Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA
| | - John W. Dutton
- Southwest National Primate Research Center, Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA;
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Haegeman A, De Leeuw I, Mostin L, Campe WV, Aerts L, Venter E, Tuppurainen E, Saegerman C, De Clercq K. Comparative Evaluation of Lumpy Skin Disease Virus-Based Live Attenuated Vaccines. Vaccines (Basel) 2021; 9:vaccines9050473. [PMID: 34066658 PMCID: PMC8151199 DOI: 10.3390/vaccines9050473] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/28/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022] Open
Abstract
Vaccines form the cornerstone of any control, eradication and preventative strategy and this is no different for lumpy skin disease. However, the usefulness of a vaccine is determined by a multiplicity of factors which include stability, efficiency, safety and ease of use, to name a few. Although the vaccination campaign in the Balkans against lumpy skin disease virus (LSDV) was successful and has been implemented with success in the past in other countries, data of vaccine failure have also been reported. It was therefore the purpose of this study to compare five homologous live attenuated LSDV vaccines (LSDV LAV) in a standardized setting. All five LSDV LAVs studied were able to protect against a challenge with virulent LSDV. Aside from small differences in serological responses, important differences were seen in side effects such as a local reaction and a Neethling response upon vaccination between the analyzed vaccines. These observations can have important implications in the applicability in the field for some of these LSDV LAVs.
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Affiliation(s)
- Andy Haegeman
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
- Correspondence:
| | - Ilse De Leeuw
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
| | - Laurent Mostin
- Experimental Center Machelen, Sciensano, Kerklaan 68, B-1830 Machelen, Belgium; (L.M.); (W.V.C.)
| | - Willem Van Campe
- Experimental Center Machelen, Sciensano, Kerklaan 68, B-1830 Machelen, Belgium; (L.M.); (W.V.C.)
| | - Laetitia Aerts
- EURL for Diseases Caused by Capripox Viruses, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium;
| | - Estelle Venter
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa;
- College of Public Health, Medical and Veterinary Sciences, Discipline: Veterinary Science, James Cook University, Townsville, QLD 4811, Australia
| | - Eeva Tuppurainen
- Institut für Internationale Tiergesundheit/One Health, Friedrich-Loeffler-Institut Federal Research Institute for Animal Health, 17489 Greifswald-Insel Riems, Germany;
| | - Claude Saegerman
- Fundamental and Applied Research for Animals & Health (FARAH) Center, Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiège), Faculty of Veterinary Medicine, University of Liege, 4000 Liege, Belgium;
| | - Kris De Clercq
- Infectious Diseases in Animals, Exotic and Particular Diseases, Sciensano, Groeselenberg 99, B-1180 Brussels, Belgium; (I.D.L.); (K.D.C.)
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Rhazi H, Safini N, Mikou K, Alhyane M, Lenk M, Tadlaoui KO, Elharrak M. Comparative sensitivity study of primary cells, vero, OA3.Ts and ESH-L cell lines to lumpy skin disease, sheeppox, and goatpox viruses detection and growth. J Virol Methods 2021; 293:114164. [PMID: 33864853 DOI: 10.1016/j.jviromet.2021.114164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/09/2021] [Accepted: 04/10/2021] [Indexed: 10/21/2022]
Abstract
Lumpy skin disease virus (LSDV), sheeppox virus (SPPV) and goatpox (GTPV) virus have been usually grown on primary cells for diagnosis, production and titration purposes. The use of primary cells present several inconvenient, heavy preparation, heterogeneous cell population, non-reproducible viral titration and presence of potential endogenous contaminants. Therefore investigating sensitivity of candidate continuous cell lines is needed. In this study, we compared the above Capripox viruses (CaPVs) sensitivity of primary cells of four origin (heart, skin, testis and kidney), with three cell lines (Vero, OA3.Ts and ESH-L). We tested sensitivity for virus isolation, replication cycle and titration, revealed by cytopathic effect (CPE), immunoenzymatic staining and immunofluorescence. Our results show that ESH-L cells and primary fetal heart cells present the highest sensitivity for CaPVs growth and detection. Vero cells can replicate those viruses but without showing any CPE while the titer obtained on OA3.Ts is lower than primary and ESH-L cells. ESH-L cells are an effective alternative to primary cells use for growing Capripoxviruses and their diagnosis.
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Affiliation(s)
- Halima Rhazi
- Laboratory of functional and environmental ecology, Faculty of Sciences and Technology Sidi Mohammed Ben Abdellah University, Imouzzer Road, BP 2202 Fez, Morocco; Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco.
| | - Najete Safini
- Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco
| | - Karima Mikou
- Laboratory of functional and environmental ecology, Faculty of Sciences and Technology Sidi Mohammed Ben Abdellah University, Imouzzer Road, BP 2202 Fez, Morocco
| | - Meryeme Alhyane
- Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco
| | - Matthias Lenk
- Departement of Experimental Animal Facilities and Biorisk Management, Collection of Cell Lines in Veterinary Medicine, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, D-17493, Greifswald, Insel Riems, Germany
| | - Khalid Omari Tadlaoui
- Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco
| | - Mehdi Elharrak
- Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco
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Kumar N, Chander Y, Kumar R, Khandelwal N, Riyesh T, Chaudhary K, Shanmugasundaram K, Kumar S, Kumar A, Gupta MK, Pal Y, Barua S, Tripathi BN. Isolation and characterization of lumpy skin disease virus from cattle in India. PLoS One 2021; 16:e0241022. [PMID: 33428633 PMCID: PMC7799759 DOI: 10.1371/journal.pone.0241022] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022] Open
Abstract
Lumpy skin disease (LSD) has devastating economic impact. During the last decade, LSD had spread to climatically new and previously disease-free countries, which also includes its recent emergence in the Indian subcontinent (2019). This study deals with the LSD outbreak(s) from cattle in Ranchi (India). Virus was isolated from the scabs (skin lesions) in the primary goat kidney cells. Phylogenetic analysis based on nucleotide sequencing of LSD virus (LSDV) ORF011, ORF012 and ORF036 suggested that the isolated virus (LSDV/Bos taurus-tc/India/2019/Ranchi) is closely related to Kenyan LSDV strains. Further, we adapted the isolated virus in Vero cells. Infection of the isolated LSDV to Vero cells did not produce cytopathic effect (CPE) until the 4th blind passage, but upon adaptation, it produced high viral titres in the cultured cells. The kinetics of viral DNA synthesis and one-step growth curve analysis suggested that Vero cell-adapted LSDV initiates synthesizing its genome at ~24 hours post-infection (hpi) with a peak level at ~96 hpi whereas evidence of progeny virus particles was observed at 36–48 hours (h) with a peak titre at ~120 h. To the best of our knowledge, this study describes the first successful isolation of LSDV in India, besides providing insights into the life cycle Vero cell-adapted LSDV.
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Affiliation(s)
- Naveen Kumar
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
- * E-mail: (NK); (SB); (BNT)
| | - Yogesh Chander
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | - Ram Kumar
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | - Nitin Khandelwal
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | - Thachamvally Riyesh
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | - Khushboo Chaudhary
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | | | - Sanjit Kumar
- Department of Veterinary Pathology, College of Veterinary Sciences, Birsa Agricultural University, Ranchi, India
| | - Anand Kumar
- Department of Veterinary Gynaecology and Obstetrics, College of Veterinary Sciences, Birsa Agricultural University, Ranchi, India
| | - Madhurendu K. Gupta
- Department of Veterinary Pathology, College of Veterinary Sciences, Birsa Agricultural University, Ranchi, India
| | - Yash Pal
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
| | - Sanjay Barua
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
- * E-mail: (NK); (SB); (BNT)
| | - Bhupendra N. Tripathi
- National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, India
- * E-mail: (NK); (SB); (BNT)
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Douglass N, Munyanduki H, Omar R, Gers S, Mutowembwa P, Heath L, Williamson AL. Influence of the Viral Superoxide Dismutase (SOD) Homologue on Lumpy Skin Disease Virus (LSDV) Growth, Histopathology and Pathogenicity. Vaccines (Basel) 2020; 8:vaccines8040664. [PMID: 33171875 PMCID: PMC7712962 DOI: 10.3390/vaccines8040664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 12/19/2022] Open
Abstract
Lumpy skin disease is an important economic disease of cattle that is controlled by vaccination. This paper presents an investigation into the role of the lumpy skin disease virus (LSDV) superoxide dismutase (SOD) homologue on growth and histopathology of the virus both in vitro and in vivo. SOD homologue knock-out and knock-in recombinants (nLSDV∆SOD-UCT and nLSDVSODis-UCT, respectively) were constructed and compared to the Neethling vaccine (nLSDV) for growth in a permissive bovine cell line as well as on fertilized chick chorioallantoic membranes (CAMs). The infected CAMs were scored for histological changes. Deletion of the SOD homologue from LSDV reduced virus growth both in Madin-Darby bovine kidney (MDBK) cells as well as on CAMs. Furthermore, the knockout virus showed reduced inflammation in CAMs and more ballooning degeneration. A pilot experiment was performed in cattle to compare the lesions produced by the different LSDV constructs in the same animal. One animal developed a larger lesion to nLSDV∆SOD-UCT compared to both nLSDVSODis-UCT and nLSDV. Histological analysis of biopsies of these lesions shows less inflammation and necrosis associated with nLSDVSODis-UCT compared to nLSDV and nLSDV∆SOD-UCT. None of the vaccinated animals showed disseminated LSDV disease, indicating that the candidate vaccines are safe for further testing. Our results suggest that the SOD homologue may improve immunogenicity and reduce virulence.
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Affiliation(s)
- Nicola Douglass
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (H.M.); (R.O.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
- Correspondence: ; Tel.: +27-832310553
| | - Henry Munyanduki
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (H.M.); (R.O.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, UK
| | - Ruzaiq Omar
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (H.M.); (R.O.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
| | | | | | - Livio Heath
- Onderstepoort Veterinary Institute, ARC, Gauteng 0110, South Africa; (P.M.); (L.H.)
| | - Anna-Lise Williamson
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (H.M.); (R.O.); (A.-L.W.)
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
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Fay PC, Cook CG, Wijesiriwardana N, Tore G, Comtet L, Carpentier A, Shih B, Freimanis G, Haga IR, Beard PM. Madin-Darby bovine kidney (MDBK) cells are a suitable cell line for the propagation and study of the bovine poxvirus lumpy skin disease virus. J Virol Methods 2020; 285:113943. [PMID: 32707050 PMCID: PMC7561597 DOI: 10.1016/j.jviromet.2020.113943] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 11/30/2022]
Abstract
LSDV replicates to high titers (approximately 1 × 107 PFU/mL) in MDBK cells. LSDV forms foci-like poxviral plaques in MDBK cells. A plaque-reduction neutralisation test was developed for LSDV antibody quantitation. A method for purification of LSDV genomic DNA was optimized.
Lumpy skin disease virus (LSDV) is a poxvirus that causes systemic disease in cattle, resulting in substantial economic loss to affected communities. LSDV is a rapidly emerging pathogen of growing global concern that recently spread from Africa and the Middle East into Europe and Asia, impacting the cattle population in these regions. An increase in research efforts into LSDV is required to address key knowledge gaps, however this is hampered by lack of suitable cell lines on which to propagate and study the virus. In this work we describe the replication and spread of LSDV on Madin-Darby bovine kidney (MDBK) cells, and the formation of foci-type poxvirus plaques by LSDV on MDBK cells. Methods utilising MDBK cells to quantify neutralising antibodies to LSDV, and to purify LSDV genomic DNA suitable for short read sequencing are described. These research methods broaden the tools available for LSDV researchers and will facilitate the gathering of evidence to underpin the development of LSD control and prevention programmes.
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Affiliation(s)
- Petra C Fay
- The Pirbright Institute, Ash Rd, Surrey, GU24 0NF, UK
| | | | | | - Gessica Tore
- The Pirbright Institute, Ash Rd, Surrey, GU24 0NF, UK
| | - Loic Comtet
- IDvet, 310 Rue Louis Pasteur, 34790, Grabels, France
| | | | - Barbara Shih
- The Roslin Institute / Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | | | - Ismar R Haga
- The Pirbright Institute, Ash Rd, Surrey, GU24 0NF, UK
| | - Philippa M Beard
- The Pirbright Institute, Ash Rd, Surrey, GU24 0NF, UK; The Roslin Institute / Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
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