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Carpenter M, Kopanke J, Lee J, Rodgers C, Reed K, Sherman TJ, Graham B, Cohnstaedt LW, Wilson WC, Stenglein M, Mayo C. Evaluating Temperature Effects on Bluetongue Virus Serotype 10 and 17 Coinfection in Culicoides sonorensis. Int J Mol Sci 2024; 25:3063. [PMID: 38474308 PMCID: PMC10932384 DOI: 10.3390/ijms25053063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Bluetongue virus (BTV) is a segmented, double-stranded RNA virus transmitted by Culicoides midges that infects ruminants. As global temperatures increase and geographical ranges of midges expand, there is increased potential for BTV outbreaks from incursions of novel serotypes into endemic regions. However, an understanding of the effect of temperature on reassortment is lacking. The objectives of this study were to compare how temperature affected Culicoides survival, virogenesis, and reassortment in Culicoides sonorensis coinfected with two BTV serotypes. Midges were fed blood meals containing BTV-10, BTV-17, or BTV serotype 10 and 17 and maintained at 20 °C, 25 °C, or 30 °C. Midge survival was assessed, and pools of midges were collected every other day to evaluate virogenesis of BTV via qRT-PCR. Additional pools of coinfected midges were collected for BTV plaque isolation. The genotypes of plaques were determined using next-generation sequencing. Warmer temperatures impacted traits related to vector competence in offsetting ways: BTV replicated faster in midges at warmer temperatures, but midges did not survive as long. Overall, plaques with BTV-17 genotype dominated, but BTV-10 was detected in some plaques, suggesting parental strain fitness may play a role in reassortment outcomes. Temperature adds an important dimension to host-pathogen interactions with implications for transmission and evolution.
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Affiliation(s)
- Molly Carpenter
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Jennifer Kopanke
- Department of Comparative Medicine, Oregon Health & Science University, Portland, OR 97239, USA;
| | - Justin Lee
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Case Rodgers
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Kirsten Reed
- Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Tyler J. Sherman
- Diagnostic Medicine Center, Colorado State University, 2450 Gillette Drive, Fort Collins, CO 80526, USA;
| | - Barbara Graham
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Lee W. Cohnstaedt
- Foreign Arthropod-Borne Animal Diseases Research Unit, The National Bio and Agro-Defense Facility, USDA Agricultural Research Service, P.O. Box 1807, Manhattan, KS 66505, USA; (L.W.C.); (W.C.W.)
| | - William C. Wilson
- Foreign Arthropod-Borne Animal Diseases Research Unit, The National Bio and Agro-Defense Facility, USDA Agricultural Research Service, P.O. Box 1807, Manhattan, KS 66505, USA; (L.W.C.); (W.C.W.)
| | - Mark Stenglein
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Christie Mayo
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
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Carpenter M, Kopanke J, Lee J, Rodgers C, Reed K, Sherman TJ, Graham B, Stenglein M, Mayo C. Assessing Reassortment between Bluetongue Virus Serotypes 10 and 17 at Different Coinfection Ratios in Culicoides sonorenesis. Viruses 2024; 16:240. [PMID: 38400016 PMCID: PMC10893243 DOI: 10.3390/v16020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Bluetongue virus (BTV) is a segmented, double-stranded RNA orbivirus listed by the World Organization for Animal Health and transmitted by Culicoides biting midges. Segmented viruses can reassort, which facilitates rapid and important genotypic changes. Our study evaluated reassortment in Culicoides sonorensis midges coinfected with different ratios of BTV-10 and BTV-17. Midges were fed blood containing BTV-10, BTV-17, or a combination of both serotypes at 90:10, 75:25, 50:50, 25:75, or 10:90 ratios. Midges were collected every other day and tested for infection using pan BTV and cox1 (housekeeping gene) qRT-PCR. A curve was fit to the ∆Ct values (pan BTV Ct-cox1 Ct) for each experimental group. On day 10, the midges were processed for BTV plaque isolation. Genotypes of the plaques were determined by next-generation sequencing. Pairwise comparison of ∆Ct curves demonstrated no differences in viral RNA levels between coinfected treatment groups. Plaque genotyping indicated that most plaques fully aligned with one of the parental strains; however, reassortants were detected, and in the 75:25 pool, most plaques were reassortant. Reassortant prevalence may be maximized upon the occurrence of reassortant genotypes that can outcompete the parental genotypes. BTV reassortment and resulting biological consequences are important elements to understanding orbivirus emergence and evolution.
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Affiliation(s)
- Molly Carpenter
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Jennifer Kopanke
- Department of Comparative Medicine, Oregon Health & Science University, Portland, OR 97239, USA;
| | - Justin Lee
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Case Rodgers
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Kirsten Reed
- Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Tyler J. Sherman
- Diagnostic Medicine Center, Colorado State University, Fort Collins, CO 80526, USA;
| | - Barbara Graham
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Mark Stenglein
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Christie Mayo
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
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Field-Reassortment of Bluetongue Virus Illustrates Plasticity of Virus Associated Phenotypic Traits in the Arthropod Vector and Mammalian Host In Vivo. J Virol 2022; 96:e0053122. [PMID: 35727032 PMCID: PMC9278112 DOI: 10.1128/jvi.00531-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Segmented RNA viruses are a taxonomically diverse group that can infect plant, wildlife, livestock and human hosts. A shared feature of these viruses is the ability to exchange genome segments during coinfection of a host by a process termed "reassortment." Reassortment enables rapid evolutionary change, but where transmission involves a biological arthropod vector, this change is constrained by the selection pressures imposed by the requirement for replication in two evolutionarily distant hosts. In this study, we use an in vivo, host-arbovirus-vector model to investigate the impact of reassortment on two phenotypic traits, virus infection rate in the vector and virulence in the host. Bluetongue virus (BTV) (Reoviridae) is the causative agent of bluetongue (BT), an economically important disease of domestic and wild ruminants and deer. The genome of BTV comprises 10 linear segments of dsRNA, and the virus is transmitted between ruminants by Culicoides biting midges (Diptera: Ceratopogonidae). Five strains of BTV representing three serotypes (BTV-1, BTV-4, and BTV-8) were isolated from naturally infected ruminants in Europe and ancestral/reassortant lineage status assigned through full genome sequencing. Each strain was then assessed in parallel for the ability to replicate in vector Culicoides and to cause BT in sheep. Our results demonstrate that two reassortment strains, which themselves became established in the field, had obtained high replication ability in C. sonorensis from one of the ancestral virus strains, which allowed inferences of the genome segments conferring this phenotypic trait. IMPORTANCE Reassortment between virus strains can lead to major shifts in the transmission parameters and virulence of segmented RNA viruses, with consequences for spread, persistence, and impact. The ability of these pathogens to adapt rapidly to their environment through this mechanism presents a major challenge in defining the conditions under which emergence can occur. Utilizing a representative mammalian host-insect vector infection and transmission model, we provide direct evidence of this phenomenon in closely related ancestral and reassortant strains of BTV. Our results demonstrate that efficient infection of Culicoides observed for one of three ancestral BTV strains was also evident in two reassortant strains that had subsequently emerged in the same ecosystem.
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Kopanke J, Carpenter M, Lee J, Reed K, Rodgers C, Burton M, Lovett K, Westrich JA, McNulty E, McDermott E, Barbera C, Cavany S, Rohr JR, Perkins TA, Mathiason CK, Stenglein M, Mayo C. Bluetongue Research at a Crossroads: Modern Genomics Tools Can Pave the Way to New Insights. Annu Rev Anim Biosci 2022; 10:303-324. [PMID: 35167317 DOI: 10.1146/annurev-animal-051721-023724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bluetongue virus (BTV) is an arthropod-borne, segmented double-stranded RNA virus that can cause severe disease in both wild and domestic ruminants. BTV evolves via several key mechanisms, including the accumulation of mutations over time and the reassortment of genome segments.Additionally, BTV must maintain fitness in two disparate hosts, the insect vector and the ruminant. The specific features of viral adaptation in each host that permit host-switching are poorly characterized. Limited field studies and experimental work have alluded to the presence of these phenomena at work, but our understanding of the factors that drive or constrain BTV's genetic diversification remains incomplete. Current research leveraging novel approaches and whole genome sequencing applications promises to improve our understanding of BTV's evolution, ultimately contributing to the development of better predictive models and management strategies to reduce future impacts of bluetongue epizootics.
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Affiliation(s)
- Jennifer Kopanke
- Office of the Campus Veterinarian, Washington State University, Spokane, Washington, USA;
| | - Molly Carpenter
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Justin Lee
- Genomic Sequencing Laboratory, Centers for Disease Control and Prevention, Atlanta, Georgia, USA;
| | - Kirsten Reed
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Case Rodgers
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Mollie Burton
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Kierra Lovett
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Joseph A Westrich
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Erin McNulty
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Emily McDermott
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, Arkansas, USA;
| | - Carly Barbera
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA; , , ,
| | - Sean Cavany
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA; , , ,
| | - Jason R Rohr
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA; , , ,
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA; , , ,
| | - Candace K Mathiason
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Mark Stenglein
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
| | - Christie Mayo
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; , , , , , , , , ,
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Kopanke J, Lee J, Stenglein M, Mayo C. In Vitro Reassortment between Endemic Bluetongue Viruses Features Global Shifts in Segment Frequencies and Preferred Segment Combinations. Microorganisms 2021; 9:microorganisms9020405. [PMID: 33669284 PMCID: PMC7920030 DOI: 10.3390/microorganisms9020405] [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: 01/25/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Bluetongue virus (BTV) is an arthropod-borne pathogen that is associated with sometimes severe disease in both domestic and wild ruminants. Predominantly transmitted by Culicoides spp. biting midges, BTV is composed of a segmented, double-stranded RNA genome. Vector expansion and viral genetic changes, such as reassortment between BTV strains, have been implicated as potential drivers of ongoing BTV expansion into previously BTV-free regions. We used an in vitro system to investigate the extent and flexibility of reassortment that can occur between two BTV strains that are considered enzootic to the USA, BTV-2 and BTV-10. Whole genome sequencing (WGS) was coupled with plaque isolation and a novel, amplicon-based sequencing approach to quantitate the viral genetic diversity generated across multiple generations of in vitro propagation. We found that BTV-2 and BTV-10 were able to reassort across multiple segments, but that a preferred BTV-2 viral backbone emerged in later passages and that certain segments were more likely to be found in reassortant progeny. Our findings indicate that there may be preferred segment combinations that emerge during BTV reassortment. Moreover, our work demonstrates the usefulness of WGS and amplicon-based sequencing approaches to improve understanding of the dynamics of reassortment among segmented viruses such as BTV.
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Veronesi E, Darpel K, Gubbins S, Batten C, Nomikou K, Mertens P, Carpenter S. Diversity of Transmission Outcomes Following Co-Infection of Sheep with Strains of Bluetongue Virus Serotype 1 and 8. Microorganisms 2020; 8:microorganisms8060851. [PMID: 32516979 PMCID: PMC7356686 DOI: 10.3390/microorganisms8060851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/31/2020] [Accepted: 06/02/2020] [Indexed: 01/03/2023] Open
Abstract
Bluetongue virus (BTV) causes an economically important disease, bluetongue (BT), in susceptible ruminants and is transmitted primarily by species of Culicoides biting midges (Diptera: Ceratopogonidae). Since 2006, northern Europe has experienced multiple incursions of BTV through a variety of routes of entry, including major outbreaks of strains of BTV serotype 8 (BTV-8) and BTV serotype 1 (BTV-1), which overlapped in distribution within southern Europe. In this paper, we examined the variation in response to coinfection with strains of BTV-1 and BTV-8 using an in vivo transmission model involving Culicoides sonorensis, low passage virus strains, and sheep sourced in the United Kingdom. In the study, four sheep were simultaneously infected using BTV-8 and BTV-1 intrathoracically inoculated C. sonorensis and co-infections of all sheep with both strains were established. However, there were significant variations in both the initiation and peak levels of virus RNA detected throughout the experiment, as well as in the infection rates in the C. sonorensis that were blood-fed on experimentally infected sheep at peak viremia. This is discussed in relation to the potential for reassortment between these strains in the field and the policy implications for detection of BTV strains.
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Affiliation(s)
- Eva Veronesi
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, 8057 Zurich, Switzerland
- Correspondence: (E.V.); (S.C.)
| | - Karin Darpel
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
| | - Simon Gubbins
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
| | - Carrie Batten
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
| | - Kyriaki Nomikou
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
- University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD, UK
| | - Peter Mertens
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
- University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD, UK
| | - Simon Carpenter
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK; (K.D.); (S.G.); (C.B.); (K.N.); (P.M.)
- Correspondence: (E.V.); (S.C.)
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7
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Van den Bergh C, Coetzee P, Venter EH. Reassortment of bluetongue virus vaccine serotypes in cattle. J S Afr Vet Assoc 2018; 89:e1-e7. [PMID: 30551703 PMCID: PMC6295955 DOI: 10.4102/jsava.v89i0.1649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 11/01/2022] Open
Abstract
Bluetongue is primarily a disease of sheep in South Africa, while cattle and goats are mostly subclinically infected. The viraemia of bluetongue virus in cattle lasts much longer than in sheep and the role of cattle in the epidemiology of bluetongue in South Africa is poorly understood. Bluetongue virus has a segmented double-stranded ribonucleic acid genome and reassortment of genomes is a common feature. The aim of the study was to investigate whether reassortment occurs between vaccine and field strains when simultaneously administered to cattle. Six cattle between the ages of 6 and 12 months were infected with five strains of modified live vaccine bluetongue virus and a virulent field isolate of bluetongue virus 4. Blood samples were subsequently collected daily from these animals from day 1 to day 39 post-inoculation. Viruses were directly isolated during viraemia from the buffy coat on Vero cells using the plaque forming unit method. Analysis of plaques indicated that no reassortants between virulent field and vaccine strains occurred and the virulent bluetongue virus 4 was identified as the predominant virus strain. However, a reassortant virus between two bluetongue virus vaccine strains was isolated from the buffy coat. Whole genome sequences from the vaccine viruses were compared to the suspected reassortant and it was found that segment 8 exchanged between the bluetongue virus 8 and bluetongue virus 9 vaccine strains. The use of the live-attenuated bluetongue virus multivalent vaccine in South Africa causes circulation of different vaccine serotypes in Culicoides spp. and susceptible hosts and cattle might provide the ideal host for reassortment to occur.
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Martinelle L, Dal Pozzo F, Thys C, De Leeuw I, Van Campe W, De Clercq K, Thiry E, Saegerman C. Assessment of cross-protection induced by a bluetongue virus (BTV) serotype 8 vaccine towards other BTV serotypes in experimental conditions. Vet Res 2018; 49:63. [PMID: 30012223 PMCID: PMC6048908 DOI: 10.1186/s13567-018-0556-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/25/2018] [Indexed: 02/06/2023] Open
Abstract
Bluetongue disease is caused by bluetongue virus (BTV) and BTV serotype 8 (BTV8) caused great economic damage in Europe during the last decade. From 1998 to 2007, in addition to BTV8, Europe had to face the emergence of BTV1, 2, 4, 9, and 16, spreading in countries where the virus has never been detected before. These unprecedented outbreaks trigger the need to evaluate and compare the clinical, virological and serological features of the European BTV serotypes in the local epidemiological context. In this study groups of calves were infected with one of the following European BTV serotypes, namely BTV1, 2, 4, 9 and 16. For each tested serotype, two groups of three male Holstein calves were used: one group vaccinated against BTV8, the other non-vaccinated. Clinical signs were quantified, viral RNA was detected in blood and organs and serological relationship was assessed. Calves were euthanized 35 days post-infection and necropsied. Most of the infected animals showed mild clinical signs. A partial serological cross reactivity has been reported between BTV8 and BTV4, and between BTV1 and BTV8. BTV2 and BTV4 viral RNA only reached low levels in blood, when compared to other serotypes, whereas in vitro growth assays could not highlight significant differences. Altogether the results of this study support the hypothesis of higher adaptation of some BTV strains to specific hosts, in this case calves. Furthermore, cross-protection resulting from a prior vaccination with BTV8 was highlighted based on cross-neutralization. However, the development of neutralizing antibodies is probably not totally explaining the mild protection induced by the heterologous vaccination.
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Affiliation(s)
- Ludovic Martinelle
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | - Fabiana Dal Pozzo
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | - Christine Thys
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | | | | | | | - Etienne Thiry
- Faculty of Veterinary Medicine, Fundamental and Applied Research for Animal and Health (FARAH) Center, Veterinary Virology and Animal Viral Diseases, University of Liege, Liege, Belgium
| | - Claude Saegerman
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium.
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9
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Schirtzinger EE, Jasperson DC, Ostlund EN, Johnson DJ, Wilson WC. Recent US bluetongue virus serotype 3 isolates found outside of Florida indicate evidence of reassortment with co-circulating endemic serotypes. J Gen Virol 2017; 99:157-168. [PMID: 29120297 PMCID: PMC5882081 DOI: 10.1099/jgv.0.000965] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Since 1999, 11 serotypes of bluetongue virus (BTV) similar to Central American or Caribbean strains have been isolated in the southeastern United States, predominantly in Florida. The majority of the incursive serotypes have remained restricted to the southeastern US. In recent years, BTV serotype 3 (BTV-3) has been isolated in areas increasingly distant from Florida. The current study uses whole genome sequencing of recent and historical BTV-3 isolates from the US, Central America and the Caribbean with additional sequences from GenBank to conduct phylogenetic analyses. The individual segments of the BTV genome were analysed to determine if recent BTV-3 isolates are reassortants containing genomic segments from endemic US serotypes or if they retain a majority of Central American/Caribbean genotypes. The analyses indicate that BTV-3 isolates Mississippi 2006, Arkansas 2008 and Mississippi 2009 are closely related reassortants that contain five to six genomic segments that are of US origin and two to three segments of Central American/Caribbean origin. In contrast, the BTV-3 South Dakota 2012 isolate contains seven genomic segments that are more similar to isolates from Central American and the Caribbean. These different evolutionary histories of the BTV-3 isolates suggest that there are at least two different lineages of BTV-3 that are currently circulating in the US.
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Affiliation(s)
- Erin E Schirtzinger
- United States Department of Agriculture, Agricultural Research Service, Arthropod-borne Animal Diseases Research Unit, 1515 College Avenue, Manhattan, KS 66502, USA
| | - Dane C Jasperson
- United States Department of Agriculture, Agricultural Research Service, Arthropod-borne Animal Diseases Research Unit, 1515 College Avenue, Manhattan, KS 66502, USA
| | - Eileen N Ostlund
- United States Department of Agriculture, Animal-Plant Health Inspection Service, National Veterinary Service Laboratories, Diagnostic Virology Laboratory, PO Box 844, Ames, IA 50010, USA
| | - Donna J Johnson
- United States Department of Agriculture, Animal-Plant Health Inspection Service, National Veterinary Service Laboratories, Diagnostic Virology Laboratory, PO Box 844, Ames, IA 50010, USA
| | - William C Wilson
- United States Department of Agriculture, Agricultural Research Service, Arthropod-borne Animal Diseases Research Unit, 1515 College Avenue, Manhattan, KS 66502, USA
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10
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Maclachlan NJ, Osburn BI. Teratogenic bluetongue and related orbivirus infections in pregnant ruminant livestock: timing and pathogen genetics are critical. Curr Opin Virol 2017; 27:31-35. [PMID: 29107849 DOI: 10.1016/j.coviro.2017.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 09/26/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
Abstract
Congenital infections of domestic animals with viruses in several families, including Bunyaviridae, Flaviridae, Parvoviridae, and Reoviridae, are the cause of naturally occurring teratogenic central nervous system and/or musculoskeletal defects (arthrogryposis) in domestic animals. Congenital infections of ruminant livestock with bluetongue virus (BTV) and some related members of the genus Orbivirus (family Reoviridae) have clearly shown the critical role of gestational age at infection in determining outcome. Specifically, fetuses infected prior to mid-gestation that survive congenital BTV infection are born with cavitating central nervous system defects that range from severe hydranencephaly to cerebral cysts (porencephaly). Generally, the younger the fetus (in terms of gestational age) at infection, the more severe the teratogenic lesion at birth. Age-dependent virus infection and destruction of neuronal and/or glial cell precursors that populate the developing central nervous system are responsible for these naturally occurring virus-induced congenital defects of animals, thus lesions are most severe when progenitor cells are infected prior to their normal migration during embryogenesis. Whereas congenital infection is characteristic of certain BTV strains, notably live-attenuated (modified-live) vaccine viruses that have been passaged in embryonating eggs, transplacental transmission is not characteristic of many field strains of the virus and much remains to be determined regarding the genetic determinants of transplacental transmission of individual virus strains.
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Affiliation(s)
- N James Maclachlan
- School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | - Bennie I Osburn
- School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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11
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Weyer CT, Grewar JD, Burger P, Joone C, Lourens C, MacLachlan NJ, Guthrie AJ. Dynamics of African horse sickness virus nucleic acid and antibody in horses following immunization with a commercial polyvalent live attenuated vaccine. Vaccine 2017; 35:2504-2510. [PMID: 28341113 DOI: 10.1016/j.vaccine.2017.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 02/24/2017] [Accepted: 03/03/2017] [Indexed: 10/19/2022]
Abstract
African horse sickness (AHS) is a fatal disease of equids relevant to the global equine industry. Detection of AHS virus (AHSV) during outbreaks has become more rapid and efficient with the advent of group specific reverse transcriptase quantitative polymerase chain reaction (GS RT-qPCR) assays to detect AHSV nucleic acid. Use of GS RT-qPCR together with recently described type specific (TS RT-qPCR) assays cannot only expedite diagnosis of AHS but also facilitate further evaluation of the dynamics of AHSV infection in the equine host. A potential limitation to the application of these assays is that they detect viral nucleic acid originating from any AHS live attenuated vaccine (LAV), which is the vaccine type routinely administered to horses in South Africa. The aim of this study was to contrast the dynamics and duration of the RNAaemia to the serological responses of horses following immunization with a commercial polyvalent AHSV-LAV using GS and TS RT-qPCR assays and serum neutralisation tests. The results of the study showed extended RNAemia in vaccinated horses, and that more horses tested positive on GS RT-qPCR with lower Cq values after receiving the AHSV-LAV containing types 1, 3 and 4 prior to the vaccine containing types 2, 6, 7 and 8, rather than when the vaccine combinations were reversed. Furthermore, lower Cq values were obtained when vaccines were administered 4weeks apart as compared with a longer interval or 12weeks apart. These findings are of particular relevance in regions where AHSV-LAVs are used as the use of these vaccines may complicate the accurate interpretation of diagnostic testing results.
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Affiliation(s)
- C T Weyer
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
| | - J D Grewar
- Western Cape Department of Agriculture, Veterinary Services, Elsenburg, South Africa
| | - P Burger
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - C Joone
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - C Lourens
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - N J MacLachlan
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; Equine Viral Diseases Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA, United States
| | - A J Guthrie
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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12
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Abstract
Bluetongue virus (BTV) is the type species of genus Orbivirus within family Reoviridae. Bluetongue virus is transmitted between its ruminant hosts by the bite of Culicoides spp. midges. Severe BT cases are characterized by symptoms including hemorrhagic fever, particularly in sheep, loss of productivity, and death. To date, 27 BTV serotypes have been documented. These include novel isolates of atypical BTV, which have been almost fully characterized using deep sequencing technologies and do not rely on Culicoides vectors for their transmission among hosts. Due to its high economic impact, BT is an Office International des Epizooties (OIE) listed disease that is strictly controlled in international commercial exchanges. During the 20th century, BTV has been endemic in subtropical regions. In the last 15 years, novel strains of nine "typical" BTV serotypes (1, 2, 4, 6, 8, 9, 11, 14, and 16) invaded Europe, some of which caused disease in naive sheep and unexpectedly in bovine herds (particularly serotype 8). Over the past few years, three novel "atypical" serotypes (25-27) were characterized during sequencing studies of animal samples from Switzerland, Kuwait, and France, respectively. Classical serotype-specific inactivated vaccines, although expensive, were very successful in controlling outbreaks as shown with the northern European BTV-8 outbreak which started in the summer of 2006. Technological jumps in deep sequencing methodologies made rapid full characterizations of BTV genome from isolates/tissues feasible. Next-generation sequencing (NGS) approaches are powerful tools to study the variability of BTV genomes on a fine scale. This paper provides information on how NGS impacted our knowledge of the BTV genome.
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13
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Martinelle L, Dal Pozzo F, Sarradin P, Van Campe W, De Leeuw I, De Clercq K, Thys C, Thiry E, Saegerman C. Experimental bluetongue virus superinfection in calves previously immunized with bluetongue virus serotype 8. Vet Res 2016; 47:73. [PMID: 27465686 PMCID: PMC4964278 DOI: 10.1186/s13567-016-0357-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/28/2016] [Indexed: 11/10/2022] Open
Abstract
The effect of a superinfection with bluetongue virus serotype 1 (BTV1) was evaluated on two groups of four calves. One group received a commercial inactivated BTV serotype 8 (BTV8) vaccine. This group and the non-vaccinated group of calves were challenged twice (4 months apart) with the European BTV8 strain isolated during the 2006–2007 epidemics. Calves were then infected with a BTV1 inoculum which was found to be unexpectedly contaminated by BTV serotype 15 (BTV15). BTV1 and BTV15 single infections were performed on two other groups of three BTV naïve calves. A severe clinical picture was obtained after superinfection with BTV1/BTV15 in both vaccinated and non-vaccinated animals and after challenge with BTV8 in non-vaccinated animals. BTV1 and BTV15 single infection caused only very slight clinical signs. After superinfection and at the viraemic peak, there were an average of above 1000 times more BTV15 genomic copies than BTV1 ones. BTV1 RNA could be detected only in the spleen of one calf whereas BTV15 RNA was found in 15 organs of seven different animals. BTV8 immunization whether it was acquired through vaccination and challenges or challenges alone did not change BTV1 or BTV15 RNA detection in superinfected animals. However in these animals a partial cross neutralization between BTV8 and BTV1 might be involved in the lower BTV1 replication versus BTV15. Infection with different serotypes can occur also in the field. Interference between virus strains, genetic reassortment and cross-protection were considered as mechanisms to explain the clinical outcomes and the other virological and immunological findings in the course of BTV1/BTV15 superinfection.
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Affiliation(s)
- Ludovic Martinelle
- Research Unit in Epidemiology and Risk Analysis Applied to the Veterinary Sciences (UREAR-ULg), Department of Infectious and Parasitic Diseases, Center for Fundamental and Applied Research for Animal and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Quartier Vallée 2, Avenue de Cureghem 7A, B42, 4000, Liège, Belgium
| | - Fabiana Dal Pozzo
- Research Unit in Epidemiology and Risk Analysis Applied to the Veterinary Sciences (UREAR-ULg), Department of Infectious and Parasitic Diseases, Center for Fundamental and Applied Research for Animal and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Quartier Vallée 2, Avenue de Cureghem 7A, B42, 4000, Liège, Belgium
| | - Pierre Sarradin
- INRA, UE 1277, Experimental Infectiology Platform, INRA-Research Centre of Tours, Nouzilly, France
| | - Willem Van Campe
- Animal Experimental Centre, CODA-CERVA, Kerklaan 68, 1830, Machelen, Belgium
| | - Ilse De Leeuw
- Unit Vesicular and Exotic Diseases, CODA-CERVA, Groeselenberg 99, Uccle, 1180, Brussels, Belgium
| | - Kris De Clercq
- Unit Vesicular and Exotic Diseases, CODA-CERVA, Groeselenberg 99, Uccle, 1180, Brussels, Belgium
| | - Christine Thys
- Research Unit in Epidemiology and Risk Analysis Applied to the Veterinary Sciences (UREAR-ULg), Department of Infectious and Parasitic Diseases, Center for Fundamental and Applied Research for Animal and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Quartier Vallée 2, Avenue de Cureghem 7A, B42, 4000, Liège, Belgium
| | - Etienne Thiry
- Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Center for Fundamental and Applied Research for Animal and Health (FARAH), University of Liege, Quartier Vallée 2, Avenue de Cureghem 10, B43bis, 4000, Liège, Belgium
| | - Claude Saegerman
- Research Unit in Epidemiology and Risk Analysis Applied to the Veterinary Sciences (UREAR-ULg), Department of Infectious and Parasitic Diseases, Center for Fundamental and Applied Research for Animal and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Quartier Vallée 2, Avenue de Cureghem 7A, B42, 4000, Liège, Belgium.
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14
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Marín-López A, Barriales D, Moreno S, Ortego J, Calvo-Pinilla E. Defeating Bluetongue virus: new approaches in the development of multiserotype vaccines. Future Virol 2016. [DOI: 10.2217/fvl-2016-0061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bluetongue virus (BTV) is a global threat to domestic and wild ruminants, causing massive economic losses throughout the world. New serotypes of the virus are rapidly emerging in different continents, unfortunately there is little cross-protection between BTV serotypes. The eradication of the virus from a region is particularly complicated in areas where multiple serotypes circulate for a long time. The present review summarizes the actual concerns about the spread of the virus and relevant approaches to develop efficient vaccines against BTV, in particular those focused on a multiserotype design.
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Affiliation(s)
| | - Diego Barriales
- Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos-Madrid, Spain
| | - Sandra Moreno
- Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos-Madrid, Spain
| | - Javier Ortego
- Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos-Madrid, Spain
| | - Eva Calvo-Pinilla
- Centro de Investigación en Sanidad Animal, INIA-CISA, Valdeolmos-Madrid, Spain
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15
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Jiménez-Clavero MA, Agüero M, San Miguel E, Mayoral T, López MC, Ruano MJ, Romero E, Monaco F, Polci A, Savini G, Gómez-Tejedor C. High Throughput Detection of Bluetongue Virus by a New Real-Time Fluorogenic Reverse Transcription—Polymerase Chain Reaction: Application on Clinical Samples from Current Mediterranean Outbreaks. J Vet Diagn Invest 2016; 18:7-17. [PMID: 16566253 DOI: 10.1177/104063870601800103] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was developed for the detection of bluetongue virus (BTV) in blood samples. A combination of primers specific for a highly conserved region in RNA segment 5 (based on Mediterranean BTV sequences) and a DNA probe bound to 5′-Taq nuclease-3′ minor groove binder (TaqMan© MGB) was used to detect a range of isolates. This real-time RT-PCR assay could detect 5.4 × 10−3 tissue culture infectious doses (TCID50) of virus per milliliter of sample, which was comparable to our current BTV diagnostic nested RT-PCR assay. The assay detected all recent Mediterranean isolates (including serotypes 2, 4, and 16), BTV vaccine strains for serotypes 2 and 4, and 15 out of the 24 BTV reference strains available (all serotypes), but did not detect the related orbiviruses epizootic hemorrhagic disease and African horse sickness viruses. Following assay evaluation, the ability of this assay to identify BTV in recent isolates (2003, 2004) from ovine and bovine samples from an epizootic outbreak in Spain was also tested. Minor nucleotide changes (detected by sequencing viral genomes) within the probe-binding region were found to have a profound effect on virus detection. This assay has the benefits of being fast and simple, and the 96-well format enables large-scale epidemiological screening for BTV, especially when combined with a high-throughput nucleic acid extraction method.
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16
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Yang H, Lv M, Sun M, Lin L, Kou M, Gao L, Liao D, Xiong H, He Y, Li H. Complete genome sequence of the first bluetongue virus serotype 7 isolate from China: evidence for entry of African-lineage strains and reassortment between the introduced and native strains. Arch Virol 2015; 161:223-7. [DOI: 10.1007/s00705-015-2624-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 09/22/2015] [Indexed: 11/28/2022]
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17
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Nomikou K, Hughes J, Wash R, Kellam P, Breard E, Zientara S, Palmarini M, Biek R, Mertens P. Widespread Reassortment Shapes the Evolution and Epidemiology of Bluetongue Virus following European Invasion. PLoS Pathog 2015; 11:e1005056. [PMID: 26252219 PMCID: PMC4529188 DOI: 10.1371/journal.ppat.1005056] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/30/2015] [Indexed: 11/24/2022] Open
Abstract
Genetic exchange by a process of genome-segment ‘reassortment’ represents an important mechanism for evolutionary change in all viruses with segmented genomes, yet in many cases a detailed understanding of its frequency and biological consequences is lacking. We provide a comprehensive assessment of reassortment in bluetongue virus (BTV), a globally important insect-borne pathogen of livestock, during recent outbreaks in Europe. Full-genome sequences were generated and analysed for over 150 isolates belonging to the different BTV serotypes that have emerged in the region over the last 5 decades. Based on this novel dataset we confirm that reassortment is a frequent process that plays an important and on-going role in evolution of the virus. We found evidence for reassortment in all ten segments without a significant bias towards any particular segment. However, we observed biases in the relative frequency at which particular segments were associated with each other during reassortment. This points to selective constraints possibly caused by functional relationships between individual proteins or genome segments and genome-wide epistatic interactions. Sites under positive selection were more likely to undergo amino acid changes in newly reassorted viruses, providing additional evidence for adaptive dynamics as a consequence of reassortment. We show that the live attenuated vaccines recently used in Europe have repeatedly reassorted with field strains, contributing to their genotypic, and potentially phenotypic, variability. The high degree of plasticity seen in the BTV genome in terms of segment origin suggests that current classification schemes that are based primarily on serotype, which is determined by only a single genome segment, are inadequate. Our work highlights the need for a better understanding of the mechanisms and epidemiological consequences of reassortment in BTV, as well as other segmented RNA viruses. Segmented viruses have genomes that are separated into multiple segments, comparable to chromosomes in higher organisms. When two segmented viruses of the same species infect the same cell, their progeny may incorporate segments picked up from the “parental” viruses. This process is called “reassortment” and represents an important way for segmented viruses to evolve. Whereas reassortment has received a lot of attention in certain segmented viruses, especially influenza A, its frequency and biological consequences remain poorly understood for most of the others. Here, we present a comprehensive analysis of the reassortment patterns in bluetongue virus, an important pathogen of livestock, during its repeated emergence in Europe in recent decades. We confirm earlier reports that reassortment is common and can involve segments derived from live vaccines used to control outbreaks. However, the mixing of viral genomes is not strictly random and reassortment is commonly followed by novel adaptive changes in the progeny virus. This points to important functional links (paired associations) between certain segments. Our findings have important implications for the classification and control of segmented viruses and generate new insights and hypotheses about the biological interactions among different parts of the bluetongue virus genome.
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Affiliation(s)
- Kyriaki Nomikou
- Vector-Borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Joseph Hughes
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Rachael Wash
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Paul Kellam
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Division of Infection and Immunity, Research Department of Infection, University College London, London, United Kingdom
| | - Emmanuel Breard
- French Agency for Food, Environment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | - Stéphan Zientara
- French Agency for Food, Environment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | - Massimo Palmarini
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Roman Biek
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, Boyd Orr Centre for Population and Ecosystem Health, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail: (RB); (PM)
| | - Peter Mertens
- Vector-Borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Woking, United Kingdom
- * E-mail: (RB); (PM)
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18
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Abstract
The objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hosts, animal disease, and geographic distribution of all arboviruses known to date to cause disease in homeotherm (endotherm) vertebrates, except those affecting exclusively man. Fifty arboviruses pathogenic for animals have been documented worldwide, belonging to seven families: Togaviridae (mosquito-borne Eastern, Western, and Venezuelan equine encephalilitis viruses; Sindbis, Middelburg, Getah, and Semliki Forest viruses), Flaviviridae (mosquito-borne yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile, Usutu, Israel turkey meningoencephalitis, Tembusu and Wesselsbron viruses; tick-borne encephalitis, louping ill, Omsk hemorrhagic fever, Kyasanur Forest disease, and Tyuleniy viruses), Bunyaviridae (tick-borne Nairobi sheep disease, Soldado, and Bhanja viruses; mosquito-borne Rift Valley fever, La Crosse, Snowshoe hare, and Cache Valley viruses; biting midges-borne Main Drain, Akabane, Aino, Shuni, and Schmallenberg viruses), Reoviridae (biting midges-borne African horse sickness, Kasba, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki, equine encephalosis, Peruvian horse sickness, and Yunnan viruses), Rhabdoviridae (sandfly/mosquito-borne bovine ephemeral fever, vesicular stomatitis-Indiana, vesicular stomatitis-New Jersey, vesicular stomatitis-Alagoas, and Coccal viruses), Orthomyxoviridae (tick-borne Thogoto virus), and Asfarviridae (tick-borne African swine fever virus). They are transmitted to animals by five groups of hematophagous arthropods of the subphyllum Chelicerata (order Acarina, families Ixodidae and Argasidae-ticks) or members of the class Insecta: mosquitoes (family Culicidae); biting midges (family Ceratopogonidae); sandflies (subfamily Phlebotominae); and cimicid bugs (family Cimicidae). Arboviral diseases in endotherm animals may therefore be classified as: tick-borne (louping ill and tick-borne encephalitis, Omsk hemorrhagic fever, Kyasanur Forest disease, Tyuleniy fever, Nairobi sheep disease, Soldado fever, Bhanja fever, Thogoto fever, African swine fever), mosquito-borne (Eastern, Western, and Venezuelan equine encephalomyelitides, Highlands J disease, Getah disease, Semliki Forest disease, yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile encephalitis, Usutu disease, Israel turkey meningoencephalitis, Tembusu disease/duck egg-drop syndrome, Wesselsbron disease, La Crosse encephalitis, Snowshoe hare encephalitis, Cache Valley disease, Main Drain disease, Rift Valley fever, Peruvian horse sickness, Yunnan disease), sandfly-borne (vesicular stomatitis-Indiana, New Jersey, and Alagoas, Cocal disease), midge-borne (Akabane disease, Aino disease, Schmallenberg disease, Shuni disease, African horse sickness, Kasba disease, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki disease, equine encephalosis, bovine ephemeral fever, Kotonkan disease), and cimicid-borne (Buggy Creek disease). Animals infected with these arboviruses regularly develop a febrile disease accompanied by various nonspecific symptoms; however, additional severe syndromes may occur: neurological diseases (meningitis, encephalitis, encephalomyelitis); hemorrhagic symptoms; abortions and congenital disorders; or vesicular stomatitis. Certain arboviral diseases cause significant economic losses in domestic animals-for example, Eastern, Western and Venezuelan equine encephalitides, West Nile encephalitis, Nairobi sheep disease, Rift Valley fever, Akabane fever, Schmallenberg disease (emerged recently in Europe), African horse sickness, bluetongue, vesicular stomatitis, and African swine fever; all of these (except for Akabane and Schmallenberg diseases) are notifiable to the World Organisation for Animal Health (OIE, 2012).
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Affiliation(s)
- Zdenek Hubálek
- Medical Zoology Laboratory, Institute of Vertebrate Biology, Academy of Sciences, v.v.i., Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
| | - Ivo Rudolf
- Medical Zoology Laboratory, Institute of Vertebrate Biology, Academy of Sciences, v.v.i., Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Norbert Nowotny
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine, Vienna, Austria; Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
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19
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Jupille H, Vega-Rua A, Rougeon F, Failloux AB. Arboviruses: variations on an ancient theme. Future Virol 2014. [DOI: 10.2217/fvl.14.62] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT Arboviruses utilize different strategies to complete their transmission cycle between vertebrate and invertebrate hosts. Most possess an RNA genome coupled with an RNA polymerase lacking proofreading activity and generate large populations of genetically distinct variants, permitting rapid adaptation to environmental changes. With mutation rates of between 10- 6 and 10-4 substitutions per nucleotide, arboviral genomes rapidly acquire mutations that can lead to viral emergence. Arboviruses can be described in seven families, four of which have medical importance: Togaviridae, Flaviviridae, Bunyaviridae and Reoviridae. The Togaviridae and Flaviviridae both have ssRNA genomes, while the Bunyaviridae and Reoviridae possess segmented RNA genomes. Recent epidemics caused by these arboviruses have been associated with specific mutations leading to enhanced host ranges, vector shifts and virulence.
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Affiliation(s)
- Henri Jupille
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
| | - Anubis Vega-Rua
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
- Cellule Pasteur UPMC, Université Pierre et Marie Curie, Paris, France
| | | | - Anna-Bella Failloux
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
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20
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Burkhardt C, Sung PY, Celma CC, Roy P. Structural constraints in the packaging of bluetongue virus genomic segments. J Gen Virol 2014; 95:2240-2250. [PMID: 24980574 PMCID: PMC4165931 DOI: 10.1099/vir.0.066647-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mechanism used by bluetongue virus (BTV) to ensure the sorting and packaging of its 10 genomic segments is still poorly understood. In this study, we investigated the packaging constraints for two BTV genomic segments from two different serotypes. Segment 4 (S4) of BTV serotype 9 was mutated sequentially and packaging of mutant ssRNAs was investigated by two newly developed RNA packaging assay systems, one in vivo and the other in vitro. Modelling of the mutated ssRNA followed by biochemical data analysis suggested that a conformational motif formed by interaction of the 5' and 3' ends of the molecule was necessary and sufficient for packaging. A similar structural signal was also identified in S8 of BTV serotype 1. Furthermore, the same conformational analysis of secondary structures for positive-sense ssRNAs was used to generate a chimeric segment that maintained the putative packaging motif but contained unrelated internal sequences. This chimeric segment was packaged successfully, confirming that the motif identified directs the correct packaging of the segment.
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Affiliation(s)
- Christiane Burkhardt
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Po-Yu Sung
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Cristina C Celma
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Polly Roy
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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21
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Molecular typing of epizootic hemorrhagic disease virus serotypes by one-step multiplex RT-PCR. J Wildl Dis 2014; 50:639-44. [PMID: 24807175 DOI: 10.7589/2013-11-302] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Epizootic hemorrhagic disease virus (EHDV) causes a highly infectious noncontagious hemorrhagic disease in wild and captive deer (Cervidae) populations in the US. Although rapid and accurate identification of the disease is important, identification of the serotype is equally important for understanding the epidemiology of the disease in white-tailed deer (Odocoileus virginianus) populations. We developed a one-step multiplex reverse transcriptase PCR assay for rapid differentiation and identification of EHDV serotypes 1, 2, and 6 in cell culture and clinical samples by targeting the viral gene segment 2 (L2) that encodes for the structural protein VP2. From 2009 to 2012, 427 clinical samples including tissue and blood (in ethylenediaminetetraacetic acid) from white-tailed deer, found EHDV positive by real-time PCR, were used to evaluate this subtyping assay. Eighteen percent of the positive samples tested were EHDV-1, 59% were EHDV-2, and 21% were EHDV-6; 2% of the samples were positive for more than one subtype, indicating mixed infection. This assay provides a rapid, sensitive, specific diagnostic tool for differentiation and identification of EHDV serotypes in field samples and virus isolates.
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22
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Coetzee P, Van Vuuren M, Stokstad M, Myrmel M, van Gennip RGP, van Rijn PA, Venter EH. Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8. Vet Microbiol 2014; 171:53-65. [PMID: 24685608 DOI: 10.1016/j.vetmic.2014.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/19/2014] [Accepted: 03/03/2014] [Indexed: 01/16/2023]
Abstract
Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus' phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo.
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Affiliation(s)
- Peter Coetzee
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa; Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - Moritz Van Vuuren
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa.
| | - Maria Stokstad
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - Mette Myrmel
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, P.O. Box 8146, 0033 Oslo, Norway.
| | - René G P van Gennip
- Department of Virology, Central Veterinary Institute of Wageningen University, P.O. Box 65, 8200 AB, Lelystad, The Netherlands.
| | - Piet A van Rijn
- Department of Virology, Central Veterinary Institute of Wageningen University, P.O. Box 65, 8200 AB, Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
| | - Estelle H Venter
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa.
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A review of experimental infections with bluetongue virus in the mammalian host. Virus Res 2014; 182:21-34. [PMID: 24462840 PMCID: PMC7132480 DOI: 10.1016/j.virusres.2013.12.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 12/27/2013] [Accepted: 12/31/2013] [Indexed: 11/23/2022]
Abstract
This review focuses on experimental infections with bluetongue virus in mammalian hosts. The objectives and justification of experimental infections with bluetongue virus are discussed. Experimental infections to study the pathogenicity, virulence, pathogenesis, and transplacental infections of bluetongue are reviewed. At the molecular and cellular levels, risks associated with reassortment/recombination of bluetongue viruses are discussed. The review is concluded with animal welfare aspects of experimental infections.
Experimental infection studies with bluetongue virus (BTV) in the mammalian host have a history that stretches back to the late 18th century. Studies in a wide range of ruminant and camelid species as well as mice have been instrumental in understanding BTV transmission, bluetongue (BT) pathogenicity/pathogenesis, viral virulence, the induced immune response, as well as reproductive failures associated with BTV infection. These studies have in many cases been complemented by in vitro studies with BTV in different cell types in tissue culture. Together these studies have formed the basis for the understanding of BTV-host interaction and have contributed to the design of successful control strategies, including the development of effective vaccines. This review describes some of the fundamental and contemporary infection studies that have been conducted with BTV in the mammalian host and provides an overview of the principal animal welfare issues that should be considered when designing experimental infection studies with BTV in in vivo infection models. Examples are provided from the authors’ own laboratory where the three Rs (replacement, reduction and refinement) have been implemented in the design of experimental infection studies with BTV in mice and goats. The use of the ARRIVE guidelines for the reporting of data from animal infection studies is emphasized.
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Lorusso A, Sghaier S, Carvelli A, Di Gennaro A, Leone A, Marini V, Pelini S, Marcacci M, Rocchigiani AM, Puggioni G, Savini G. Bluetongue virus serotypes 1 and 4 in Sardinia during autumn 2012: New incursions or re-infection with old strains? INFECTION GENETICS AND EVOLUTION 2013; 19:81-7. [DOI: 10.1016/j.meegid.2013.06.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/10/2013] [Accepted: 06/26/2013] [Indexed: 10/26/2022]
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Maclachlan NJ, Mayo CE. Potential strategies for control of bluetongue, a globally emerging, Culicoides-transmitted viral disease of ruminant livestock and wildlife. Antiviral Res 2013; 99:79-90. [DOI: 10.1016/j.antiviral.2013.04.021] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 04/25/2013] [Accepted: 04/30/2013] [Indexed: 11/16/2022]
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de Diego ACP, Sánchez-Cordón PJ, Sánchez-Vizcaíno JM. Bluetongue in Spain: From the First Outbreak to 2012. Transbound Emerg Dis 2013; 61:e1-11. [DOI: 10.1111/tbed.12068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Indexed: 01/01/2023]
Affiliation(s)
- A. C. Pérez de Diego
- VISAVET Health Surveillance Centre and Animal Health Department; Veterinary Faculty; Complutense University of Madrid; Madrid Spain
| | - P. J. Sánchez-Cordón
- Department of Comparative Pathology; Veterinary Faculty; University of Córdoba; Córdoba Spain
| | - J. M. Sánchez-Vizcaíno
- VISAVET Health Surveillance Centre and Animal Health Department; Veterinary Faculty; Complutense University of Madrid; Madrid Spain
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Shaw AE, Ratinier M, Nunes SF, Nomikou K, Caporale M, Golder M, Allan K, Hamers C, Hudelet P, Zientara S, Breard E, Mertens P, Palmarini M. Reassortment between two serologically unrelated bluetongue virus strains is flexible and can involve any genome segment. J Virol 2013; 87:543-57. [PMID: 23097432 PMCID: PMC3536370 DOI: 10.1128/jvi.02266-12] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 10/16/2012] [Indexed: 11/20/2022] Open
Abstract
Coinfection of a cell by two different strains of a segmented virus can give rise to a "reassortant" with phenotypic characteristics that might differ from those of the parental strains. Bluetongue virus (BTV) is a double-stranded RNA (dsRNA) segmented virus and the cause of bluetongue, a major infectious disease of livestock. BTV exists as at least 26 different serotypes (BTV-1 to BTV-26). Prompted by the isolation of a field reassortant between BTV-1 and BTV-8, we systematically characterized the process of BTV reassortment. Using a reverse genetics approach, our study clearly indicates that any BTV-1 or BTV-8 genome segment can be rescued in the heterologous "backbone." To assess phenotypic variation as a result of reassortment, we examined viral growth kinetics and plaque sizes in in vitro experiments and virulence in an experimental mouse model of bluetongue disease. The monoreassortants generated had phenotypes that were very similar to those of the parental wild-type strains both in vitro and in vivo. Using a forward genetics approach in cells coinfected with BTV-1 and BTV-8, we have shown that reassortants between BTV-1 and BTV-8 are generated very readily. After only four passages in cell culture, we could not detect wild-type BTV-1 or BTV-8 in any of 140 isolated viral plaques. In addition, most of the isolated reassortants contained heterologous VP2 and VP5 structural proteins, while only 17% had homologous VP2 and VP5 proteins. Our study has shown that reassortment in BTV is very flexible, and there is no fundamental barrier to the reassortment of any genome segment. Given the propensity of BTV to reassort, it is increasingly important to have an alternative classification system for orbiviruses.
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Affiliation(s)
- Andrew E. Shaw
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Maxime Ratinier
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sandro Filipe Nunes
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Marco Caporale
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Istituto G. Caporale, Teramo, Italy
| | - Matthew Golder
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kathryn Allan
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Stéphan Zientara
- French Agency for Food, Environment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | - Emmanuel Breard
- French Agency for Food, Environment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | | | - Massimo Palmarini
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Coetzee P, Stokstad M, Venter EH, Myrmel M, Van Vuuren M. Bluetongue: a historical and epidemiological perspective with the emphasis on South Africa. Virol J 2012; 9:198. [PMID: 22973992 PMCID: PMC3492172 DOI: 10.1186/1743-422x-9-198] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 08/29/2012] [Indexed: 02/08/2023] Open
Abstract
Bluetongue (BT) is a non-contagious, infectious, arthropod transmitted viral disease of domestic and wild ruminants that is caused by the bluetongue virus (BTV), the prototype member of the Orbivirus genus in the family Reoviridae. Bluetongue was first described in South Africa, where it has probably been endemic in wild ruminants since antiquity. Since its discovery BT has had a major impact on sheep breeders in the country and has therefore been a key focus of research at the Onderstepoort Veterinary Research Institute in Pretoria, South Africa. Several key discoveries were made at this Institute, including the demonstration that the aetiological agent of BT was a dsRNA virus that is transmitted by Culicoides midges and that multiple BTV serotypes circulate in nature. It is currently recognized that BT is endemic throughout most of South Africa and 22 of the 26 known serotypes have been detected in the region. Multiple serotypes circulate each vector season with the occurrence of different serotypes depending largely on herd-immunity. Indigenous sheep breeds, cattle and wild ruminants are frequently infected but rarely demonstrate clinical signs, whereas improved European sheep breeds are most susceptible. The immunization of susceptible sheep remains the most effective and practical control measure against BT. In order to protect sheep against multiple circulating serotypes, three pentavalent attenuated vaccines have been developed. Despite the proven efficacy of these vaccines in protecting sheep against the disease, several disadvantages are associated with their use in the field.
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Affiliation(s)
- Peter Coetzee
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Medicine, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa.
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Coetzee P, Van Vuuren M, Stokstad M, Myrmel M, Venter EH. Bluetongue virus genetic and phenotypic diversity: towards identifying the molecular determinants that influence virulence and transmission potential. Vet Microbiol 2012; 161:1-12. [PMID: 22835527 DOI: 10.1016/j.vetmic.2012.07.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 06/22/2012] [Accepted: 07/02/2012] [Indexed: 12/23/2022]
Abstract
Bluetongue virus (BTV) is the prototype member of the Orbivirus genus in the family Reoviridae and is the aetiological agent of the arthropod transmitted disease bluetongue (BT) that affects both ruminant and camelid species. The disease is of significant global importance due to its economic impact and effect on animal welfare. Bluetongue virus, a dsRNA virus, evolves through a process of quasispecies evolution that is driven by genetic drift and shift as well as intragenic recombination. Quasispecies evolution coupled with founder effect and evolutionary selective pressures has over time led to the establishment of genetically distinct strains of the virus in different epidemiological systems throughout the world. Bluetongue virus field strains may differ substantially from each other with regards to their phenotypic properties (i.e. virulence and/or transmission potential). The intrinsic molecular determinants that influence the phenotype of BTV have not clearly been characterized. It is currently unclear what contribution each of the viral genome segments have in determining the phenotypic properties of the virus and it is also unknown how genetic variability in the individual viral genes and their functional domains relate to differences in phenotype. In order to understand how genetic variation in particular viral genes could potentially influence the phenotypic properties of the virus; a closer understanding of the BTV virion, its encoded proteins and the evolutionary mechanisms that shape the diversity of the virus is required. This review provides a synopsis of these issues and highlights some of the studies that have been conducted on BTV and the closely related African horse sickness virus (AHSV) that have contributed to ongoing attempts to identify the molecular determinants that influence the virus' phenotype. Different strategies that can be used to generate BTV mutants in vitro and methods through which the causality between particular genetic modifications and changes in phenotype may be determined are also described. Finally examples are highlighted where a clear understanding of the molecular determinants that influence the phenotype of the virus may have contributed to risk assessment and mitigation strategies during recent outbreaks of BT in Europe.
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Affiliation(s)
- Peter Coetzee
- Department of Veterinary Tropical Diseases, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria, 0110, South Africa.
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Eschbaumer M, Wäckerlin R, Savini G, Zientara S, Sailleau C, Bréard E, Beer M, Hoffmann B. Contamination in bluetongue virus challenge experiments. Vaccine 2011; 29:4299-301. [PMID: 21557978 DOI: 10.1016/j.vaccine.2011.04.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/09/2011] [Accepted: 04/18/2011] [Indexed: 11/19/2022]
Abstract
Five cattle and five sheep that had never been exposed to bluetongue virus (BTV), as well as ten animals that had been experimentally infected with BTV-8, were inoculated with BTV-1. Previous exposure to BTV-8 did not prevent a second infection with another serotype. After the experiment, the BTV-1 preparation was found to be contaminated with BTV-15. The inoculum and blood samples taken during the experiment were analysed by serotype-specific real-time RT-PCR. There was 100-fold less BTV-15 than BTV-1 in the inoculum. Unexpectedly, BTV-15 dominated the infection in cattle that had previously been exposed to BTV-8. In sheep of both groups, on the other hand, BTV-1 prevailed over the contaminant. Regardless of the outcome, the incident demonstrates the need for a thorough contamination screening of virus preparations. For this purpose, two type-specific RT-PCR primer sets for each of the 24 established BTV serotypes as well as Toggenburg Orbivirus were designed.
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Affiliation(s)
- Michael Eschbaumer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
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Anthony SJ, Darpel KE, Maan S, Sutton G, Attoui H, Mertens PPC. The evolution of two homologues of the core protein VP6 of epizootic haemorrhagic disease virus (EHDV), which correspond to the geographical origin of the virus. Virus Genes 2009; 40:67-75. [PMID: 19830536 DOI: 10.1007/s11262-009-0410-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 09/30/2009] [Indexed: 11/25/2022]
Abstract
Epizootic haemorrhagic disease virus is a 10-segmented, double-stranded RNA virus. When these ten segments of dsRNA are run on 1% agarose, eastern (Australia, Japan) and western (North America, Africa, Middle-East) strains of the virus can be separated phenotypically based on the migration of genome segments 7-9. In western strains, segments 7-9 are roughly the same size and co-migrate as a single RNA band. In eastern strains, segment 9 is smaller, so while segments 7 and 8 co-migrate, the segment 9 RNA runs faster than its western homologue. Translation experiments demonstrated that these two segment 9 homologues are both functional and produce proteins (VP6) of different sizes-something that has not been reported in any other orbivirus species to date. Sequence analysis suggests that eastern and western versions of segment 9 (VP6) have likely evolved as a response to adaptive selection in different geographical regions via gene duplication and subsequent mutation. These significant findings are considered unusual given the conserved nature of VP6 and its presumed role as the viral helicase. It is not currently known what the biological relevance of each homologue is to the virus.
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Affiliation(s)
- S J Anthony
- Vector-Borne Diseases Program, Institute for Animal Health, Ash Road, Pirbright, Surrey, GU24 0NF, UK.
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33
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Allison AB, Goekjian VH, Potgieter AC, Wilson WC, Johnson DJ, Mertens PPC, Stallknecht DE. Detection of a novel reassortant epizootic hemorrhagic disease virus (EHDV) in the USA containing RNA segments derived from both exotic (EHDV-6) and endemic (EHDV-2) serotypes. J Gen Virol 2009; 91:430-9. [DOI: 10.1099/vir.0.015651-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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34
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Anthony SJ, Maan S, Maan N, Kgosana L, Bachanek-Bankowska K, Batten C, Darpel KE, Sutton G, Attoui H, Mertens PPC. Genetic and phylogenetic analysis of the outer-coat proteins VP2 and VP5 of epizootic haemorrhagic disease virus (EHDV): comparison of genetic and serological data to characterise the EHDV serogroup. Virus Res 2009; 145:200-10. [PMID: 19632281 DOI: 10.1016/j.virusres.2009.07.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 07/15/2009] [Accepted: 07/16/2009] [Indexed: 11/24/2022]
Abstract
The outer-coat proteins, VP2 and VP5, of epizootic haemorrhagic disease virus (EHDV) are important for host cell binding during the initiation of infection. They are also known to determine virus serotype. This study presents a complete genetic and phylogenetic analysis of these proteins (and the genes that code for them) to allow comparison of the selective pressures acting on each and the correlation of genetic sequence data with serotype. Accession numbers, gene and protein sizes, ORF positions, G+C contents, terminal hexanucleotides, start and stop codons and phylogenetic relationships are all presented. The results show that VP2 is highly variable, is under great pressure to adapt and can be correlated with serotype. While also variable, VP5 appears to be under less adaptive pressure than VP2 but still shows some correlation with serotype. Seven serotypes of EHDV have been defined in this study, although the results do show that some serotypes are extremely closely related--and highlight the benefit of using both molecular and serologic analyses. Analysis of the terminal hexanucleotides showed that the 5' terminus is under greater purifying selection than the 3'. Evidence is also presented that both segments 2 and 6 (coding for VP2 and VP5 respectively) have grown via gene duplication and subsequent mutation.
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Affiliation(s)
- S J Anthony
- Vector-borne Diseases Program, Institute for Animal Health, Ash Road, Pirbright, Surrey GU24 0NF, United Kingdom.
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35
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Maclachlan N, Drew C, Darpel K, Worwa G. The Pathology and Pathogenesis of Bluetongue. J Comp Pathol 2009; 141:1-16. [DOI: 10.1016/j.jcpa.2009.04.003] [Citation(s) in RCA: 317] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/09/2009] [Accepted: 04/20/2009] [Indexed: 11/16/2022]
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Bhanuprakash V, Indrani BK, Hosamani M, Balamurugan V, Singh RK. Bluetongue vaccines: the past, present and future. Expert Rev Vaccines 2009; 8:191-204. [PMID: 19196199 DOI: 10.1586/14760584.8.2.191] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bluetongue (BT) is a noncontagious and arboviral disease of both domestic and wild ruminants. The disease is enzootic in areas where reservoirs (cattle and wild ruminants) and vectors exist for the BT virus (BTV). A total of 24 BTV serotypes have been recognized worldwide. The major control measures include restriction of animal movement, vector control applying insecticides, slaughter of infected animals and vaccination. Prophylactic immunization of sheep against BT is the most practical and effective control measure to combat BT infection. At present, attenuated vaccines are used in the Republic of South Africa, the USA and other countries. However, EU countries were using attenuated vaccines, only recently shifting to inactivated vaccines owing to their safety and efficacy. In India, inactivated vaccines are in experimental stages and are expected to be on the market shortly. Inactivated vaccines generate serotype-specific long-lasting protective immunity after two injections, and may help in controlling epidemics. Differentiating infected from vaccinated animals (DIVA) is theoretically possible with inactivated vaccines but has not yet been developed, whereas the attenuated live vaccines are not candidates for DIVA. Attenuated live vaccines are efficacious but safety issues are of great concern. New-generation vaccines (subunit, virus-like particles, core-like particles and vectored) can be employed for DIVA. Recombinant vaccines, which generate cross-protection against multiple BTV serotypes, have great potential in BT vaccine regimens. Furthermore, new-generation vaccines are safe and efficacious experimentally, but large-scale field trials are warranted. Alternative areas, such as antivirals, siRNA, interferon and nanotechnology, may be of future use in the control of BT. We give an overview of BT vaccines, starting from conventional to recent developments, and their feasibility in controlling BT infection.
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Affiliation(s)
- V Bhanuprakash
- Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar-263 138, Nainital, Uttarakhand, India.
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Abstract
Bluetongue has been recognized as a viral disease of livestock for more than 100 years. Repeated incursions of Bluetongue into Europe since 1998 have been particularly devastating for highly sensitive European fine-wool sheep breeds, and have resulted in a resurgence of interest in vaccine manufacture. Fortunately, the virus and its serology are well understood and vaccination prevents the disease. However, current vaccines are not without their problems, and many new approaches are being tested to improve the safety and breadth of protection afforded. This review describes the leading technologies for improved bluetongue vaccines and looks ahead to how advances in other viral vaccines might be applied to this disease.
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Affiliation(s)
- Polly Roy
- Department of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E7HT, UK.
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von Teichman BF, Smit TK. Evaluation of the pathogenicity of African Horsesickness (AHS) isolates in vaccinated animals. Vaccine 2008; 26:5014-21. [DOI: 10.1016/j.vaccine.2008.07.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 11/25/2022]
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39
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Opinion of the Scientific Panel on Animal Health an Welfare (AHAW) on the EFSA Selfmandate on bluetongue origin and occurrence. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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40
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Opinion of the Scientific Panel on Animal Health and Welfare (AHAW) on request from the Commission on bluetongue vectors and vaccines. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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41
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Biek R. Evolutionary dynamics and spatial genetic structure of epizootic hemorrhagic disease virus in the eastern United States. INFECTION GENETICS AND EVOLUTION 2007; 7:651-5. [PMID: 17543590 DOI: 10.1016/j.meegid.2007.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 04/20/2007] [Accepted: 04/25/2007] [Indexed: 11/17/2022]
Abstract
Epizootic hemorrhagic disease virus (EHDV) is a significant pathogen of wild and domestic ungulates worldwide. In North America, serotype EHDV-2 is responsible for the majority of outbreaks, which are most commonly observed in white-tailed deer. A recent study by Murphy et al. [Murphy, M.D., Howerth, E.W., MacLachlan, N.J., Stallknecht, D.E., 2005. Genetic variation among epizootic hemorrhagic disease viruses in the southeastern United States: 1978-2001. Infect. Genet. Evol. 5, 157-165] examined the genetic relationships of EHDV-2 sequences from outbreaks across the eastern United States for evidence of temporal and spatial structure but found no evidence for either. Here, I present results of further examination of the same data using additional types of analysis. Contrary to the earlier assessment, I find that for outbreaks observed within the same year, genetic and spatial distances are in fact positively correlated and that the virus is evolving at a rate similar to that seen in other vector-born RNA viruses. Estimates of demographic history further revealed that population sizes of the virus had remained relatively stable over most of its history. A noticeable exception to this trend was a recent demographic bottleneck, possibly associated with a selective sweep, that affected one of the two viral genes examined. These results demonstrate that genetic variation accumulating at selectively neutral and measurably evolving sites in the EHDV-2 genome can be employed to gain insights into the spatial and temporal dynamics of this viral pathogen.
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Affiliation(s)
- Roman Biek
- Department of Biology and Center for Disease Ecology, 1510 Clifton Road, Emory University, Atlanta, GA 30322, USA.
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42
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Bréard E, Sailleau C, Hamblin C, Zientara S. Bluetongue virus in the French Island of Reunion. Vet Microbiol 2005; 106:157-65. [PMID: 15778021 DOI: 10.1016/j.vetmic.2004.11.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Revised: 10/26/2004] [Accepted: 11/19/2004] [Indexed: 10/25/2022]
Abstract
This paper records the results of a bluetongue virus (BTV) serological survey and reports the first isolation of BTV on the French Island of Reunion. In January 2003, the French Island of Reunion, located off the coast of Madagascar, reported an outbreak of disease in cattle that resembled clinical bluetongue (BT) in sheep. The suspected causal agent was isolated and identified as epizootic haemorrhagic disease of deer virus (EHDV). However, because of the similarity in the clinical signs to those of BT, a retrospective survey against BTV was carried out using sera collected in 2002. Results revealed the presence of antibody in all sera tested indicating that BTV has been resident on the Island since 2002, and probably earlier. Although up to July 2003 no clinical BT had ever been reported in sheep, BTV viral RNA was amplified by RT-PCR from a single sheep blood collected in February that year, which strongly suggested that BTV was currently circulating on the Island. Following a second outbreak of disease in August 2003, this time involving a flock of Merino sheep, infectious BTV was finally isolated, and identified by both traditional and molecular techniques as serotype 3. The nucleotide and amino-acid sequences of the RT-PCR products amplified for BTV segments 7 and 10 from the sheep blood collected in February and August from different areas of the Island, were sufficiently diverse as to suggest that they were of different origins and/or different BTV serotypes.
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Affiliation(s)
- E Bréard
- UMR 1161 AFSSA-ENVA-INRA, 23 Av. Général De Gaulle, 94704 Maisons-Alfort, France.
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43
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Figlerowicz M, Alejska M, Kurzyńska‐Kokorniak A, Figlerowicz M. Genetic variability: the key problem in the prevention and therapy of RNA-based virus infections. Med Res Rev 2003; 23:488-518. [PMID: 12710021 PMCID: PMC7168509 DOI: 10.1002/med.10045] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite extraordinary progress that has recently been made in biomedical sciences, viral infectious diseases still remain one of the most serious world health problems. Among the different types of viruses, those using RNA as their genetic material (RNA viruses and retroviruses) are especially dangerous. At present there is no medicine allowing an effective treatment of RNA-based virus infections. Many RNA viruses and retroviruses need only a few weeks to escape immune response or to produce drug-resistant mutants. This seems to be the obvious consequence of the unusual genetic variability of RNA-based viruses. An individual virus does not form a homogenous population but rather a set of similar but not identical variants. In consequence, RNA-based viruses can easily adapt to environmental changes, also those resulting from immune system response or therapy. The modifications identified within viral genes can be divided into two groups: point mutations and complex genome rearrangements. The former arises mainly during error-prone replication, whereas RNA recombination and generic reassortment are responsible for the latter. This article shortly describes major strategies used to control virus infections. Then, it presents the various mechanisms generating the genetic diversity of RNA-based viruses, which are most probably the main cause of clinical problems.
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Affiliation(s)
| | - Magdalena Alejska
- Institute of Bioorganic Chemistry Polish Academy of Sciences, Noskowskiego 12/14, 61‐704 Poznań, Poland
| | - Anna Kurzyńska‐Kokorniak
- Institute of Bioorganic Chemistry Polish Academy of Sciences, Noskowskiego 12/14, 61‐704 Poznań, Poland
| | - Marek Figlerowicz
- Institute of Bioorganic Chemistry Polish Academy of Sciences, Noskowskiego 12/14, 61‐704 Poznań, Poland
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Bonneau KR, Topol JB, Gerry AC, Mullens BA, Velten RK, MacLachlan NJ. Variation in the NS3/NS3A gene of bluetongue viruses contained in Culicoides sonorensis collected from a single site in southern California. Virus Res 2002; 84:59-65. [PMID: 11900839 DOI: 10.1016/s0168-1702(01)00415-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To determine the variability of the NS3/NS3A gene of field strains of BTV contained in Culicoides sonorensis collected from a single site in California (CA), the NS3/NS3A gene was directly amplified and sequenced from 22 pools of C. sonorensis and compared with those of previously characterized field isolates from CA, as well as to viruses that caused recent outbreaks of bluetongue disease in ruminants in CA. Phylogenetic analysis established that the NS3/NS3A gene of strains of BTV contained in C. sonorensis collected from the site exists as a heterogeneous population. The two most divergent nucleotide sequences of the NS3/NS3A genes of these viruses differed by 2.5% (18 nucleotides). Comparison with the NS3/NS3A gene sequences from viruses that caused recent instances of bluetongue disease in ruminants in CA indicated that BTV strains from different geographic regions can exhibit a higher degree of genetic heterogeneity (up to 6.6%; 0-48 nucleotide differences) than those contained in C. sonorensis collected from a single site.
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Affiliation(s)
- Kyle R Bonneau
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Haring Hall, Davis, CA 95616, USA
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45
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Meissner JD, Mecham JO, Wilson WC. Verification of bluetongue virus S9 segment nucleotide sequences. Virus Res 2001; 81:93-101. [PMID: 11682128 DOI: 10.1016/s0168-1702(01)00364-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
During the course of our bluetongue virus (BTV) nucleic acid sequence investigations, conflicts among United States (US) prototype BTV S9 genome segment sequences deposited in GenBank were noted. In order to rectify these inter-laboratory discrepancies, the S9 segments of Arthropod-borne Animal Diseases Research Laboratory (ABADRL)-stored US prototype BTV 2, BTV 10, BTV 11, BTV 13, and BTV 17 isolates were resequenced. Our S9 sequences, determined by direct sequencing of full-length reverse transcriptase-polymerase chain reaction (RT-PCR) generated amplicons, shared 99% or greater nucleotide identity with one or more respective S9 sequences previously reported. Possible sources of remaining unsupported US prototype BTV S9 sequences were evaluated by amplifying and sequencing the S9 segments of BTV 2 Ona A strain, South African (SA) prototype BTV 1, BTV 2, and BTV 4 strains, and the North American (NA) prototype epizootic hemorrhagic disease virus (EHDV) serotype 2 (Alberta) strain. Comparative analysis using these S9 sequences, as well as sequences of US BTV 2 field isolates, identified potential contributors to inter-laboratory sequence disagreements.
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Affiliation(s)
- J D Meissner
- USDA-ARS, Arthropod-Borne Animal Diseases Research Laboratory, Laramie, WY 82071-3965, USA
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46
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Bonneau KR, Mullens BA, MacLachlan NJ. Occurrence of genetic drift and founder effect during quasispecies evolution of the VP2 and NS3/NS3A genes of bluetongue virus upon passage between sheep, cattle, and Culicoides sonorensis. J Virol 2001; 75:8298-305. [PMID: 11483775 PMCID: PMC115074 DOI: 10.1128/jvi.75.17.8298-8305.2001] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2001] [Accepted: 05/29/2001] [Indexed: 11/20/2022] Open
Abstract
Bluetongue virus (BTV) is the cause of an insect-transmitted virus infection of ruminants that occurs throughout much of the world. Individual gene segments differ between field strains of BTV; thus, we hypothesized that key viral genes undergo genetic drift during alternating passage of BTV in its ruminant and insect hosts. To test this hypothesis, variation in the consensus sequence and quasispecies heterogeneity of the VP2 and NS3/NS3A genes of a plaque-purified strain of BTV serotype 10 was determined during alternating infection of vector Culicoides sonorensis and a sheep and calf. Consensus sequences were determined after reverse transcriptase-nested PCR amplification of viral RNA directly from ruminant blood and homogenized insects, and quasispecies heterogeneity was determined by the sequencing of clones derived from directly amplified viral RNA. Comparison of these sequences to those of the original BTV inoculum used to initiate the cycle of BTV infection demonstrated, for the first time, that individual BTV gene segments evolve independently of one another by genetic drift in a host-specific fashion, generating quasispecies populations in both ruminant and insect hosts. Furthermore, a unique viral variant was randomly ingested by C. sonorensis insects that fed on a sheep with low-titer viremia, thereby fixing a novel genotype by founder effect. Thus, we conclude that genetic drift and founder effect contribute to diversification of individual gene segments of field strains of BTV.
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Affiliation(s)
- K R Bonneau
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California 95616, USA
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Johnson DJ, Wilson WC, Paul PS. Validation of a reverse transcriptase multiplex PCR test for the serotype determination of U.S. isolates of bluetongue virus. Vet Microbiol 2000; 76:105-15. [PMID: 10946141 DOI: 10.1016/s0378-1135(00)00236-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bluetongue (BT) is an arthropod-borne viral disease affecting ruminants primarily in tropical and temperate regions of the world. Of the 24 serotypes of BT virus (BTV) identified worldwide, five have been found in the United States. Serotype identification of BTV isolates is important to the epidemiology of the virus, but current methods are cumbersome. A single-tube multiplex reverse transcriptase polymerase chain reaction (mRT-PCR) assay, previously developed for the serotype determination of U.S. BTV isolates, was evaluated. The determination of serotype was based on the size of the resultant amplified product. The procedure was evaluated using all 24 serotypes of BTV and nine serotypes of epizootic hemorrhagic disease virus (EHDV), a closely related orbivirus. Only the five U.S. serotypes of BTV were detected by the mRT-PCR. The assay was further tested using 132 BTV isolates originating from 24 western and southern states of the United States, from several different host species, spanning a period of 24 years. The serotypes of the isolates were determined by both a virus neutralization (VN) procedure and the mRT-PCR. Comparison of the mRT-PCR to the standard VN showed that the mRT-PCR successfully identified the serotypes of 130 of the isolates and was shown to be more reliable and specific than the VN assay.
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Affiliation(s)
- D J Johnson
- National Veterinary Services Laboratories, P.O. Box 844, Ames, IA 50010, USA.
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Calisher CH, Mertens PP. Taxonomy of African horse sickness viruses. ARCHIVES OF VIROLOGY. SUPPLEMENTUM 1998; 14:3-11. [PMID: 9785490 DOI: 10.1007/978-3-7091-6823-3_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Nine distinct genera are currently recognised within the virus family Reoviridae, which include a total of 63 virus groups or species (species = virus group = electropherotype or serogroup), comprising 214 virus serotypes or subtypes, as well as 20 provisional types or subtypes, most of which (149 + 9 tentative) are assigned to the genus Orbivirus [5, 9, 16]. The 19 species of orbiviruses (serogroups), were established principally on antigenic (serologic) grounds but many of these placements have been supported by molecular analyses. This introductory paper defines the taxonomy and classification of these viruses and establishes guidelines for use in other paper to be presented at this symposium and elsewhere.
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Affiliation(s)
- C H Calisher
- Arthropod-borne and Infectious Diseases Laboratory, Colorado State University, Fort Collins, USA
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de Mattos CC, de Mattos CA, MacLachlan NJ, Giavedoni LD, Yilma T, Osburn BI. Phylogenetic comparison of the S3 gene of United States prototype strains of bluetongue virus with that of field isolates from California. J Virol 1996; 70:5735-9. [PMID: 8764098 PMCID: PMC190544 DOI: 10.1128/jvi.70.8.5735-5739.1996] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To better define the molecular epidemiology of bluetongue virus (BTV) infection, the genetic characteristics and phylogenetic relationships of the S3 genes of the five U.S. prototype strains of BTV, the commercially available serotype 10 modified live virus vaccine, and 18 field isolates of BTV serotypes 10, 11, 13, and 17 obtained in California during 1980, 1981, 1989, and 1990 were determined. With the exception of the S3 gene of the U.S. prototype strain of BTV serotype 2 (BTV 2), these viruses had an overall sequence homology of between 95 and 100%. Phylogenetic analyses segregated the prototype U.S. BTV 2 strain to a unique branch (100% bootstrap value), whereas the rest of the viruses clustered in two main monophyletic groups that were not correlated with their serotype, year of isolation, or geographical origin. The lack of consistent association between S3 gene sequence and virus serotype likely is a consequence of reassortment of BTV gene segments during natural mixed infections of vertebrate and invertebrate hosts. The prototype strain of BTV 13, which is considered an introduction to the U.S. like BTV 2, presents an S3 gene which is highly homologous to those of some isolates of BTV 10 and especially to that of the vaccine strain. This finding strongly suggests that the U.S. prototype strain of BTV 13 is a natural reassortant. The different topologies of the phylogenetic trees of the L2 and S3 genes of the various viruses indicate that these two genome segments evolve independently. We conclude that the S3 gene segment of populations of BTV in California is formed by different consensus sequences which cocirculate and which cannot be grouped by serotype.
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Affiliation(s)
- C C de Mattos
- Department of Veterinary Pathology, University of California, Davis 95616, USA
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50
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Osburn BI, de Mattos CA, de Mattos CC, MacLachlan NJ. Bluetongue disease and the molecular epidemiology of viruses from the western United States. Comp Immunol Microbiol Infect Dis 1996; 19:181-90. [PMID: 8800543 DOI: 10.1016/0147-9571(96)00003-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Prototype and field isolates of United States bluetongue viruses were evaluated for genetic heterogeneity by sequence analyses. Prototype viruses BTV 2, 10, 11, 13 and 17 from the United States, BTV 10 vaccine virus, and field isolates of BTV 10 and 17 from California were analyzed. Gene segment 2 from BTV 10 and 17 isolated in 1980-81 and 1990 was sequenced along with gene segment 9 from BTV 10 isolates. The Wisconsin Package was used to analyze nucleotide sequences and to predict amino acid composition of the putative proteins. Phylogenetic analyses were done using DNADIST and FITCH programs of the PHYLIP Package, v. 3.4. Gene segment 2 segregated into two monophyletic groups of BTV 2 and 13 and BTV 10, 11 and 17. BTV prototype 10, isolated in 1953 and field isolates through 1980 were similar, whereas the 1990 isolates differed by 4.5%, indicating two BTV 10 monophyletic groups over 37 years. Gene segment 2 of BTV 17 prototype virus differed from the California isolates. Gene segment 9 of BTV 10 field isolates formed into two monophyletic groups. This gene segment reassorted with all serotypes. Gene segment 9 of the 1953 BTV 10 vaccine virus was essentially the same as gene segment 9 of the BTV 13 prototype virus, isolated in Idaho in 1967. This suggested that prototype BTV 13 is a reassortant virus with gene segment 9 derived from a vaccine virus parent.
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Affiliation(s)
- B I Osburn
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA
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