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Huser AF, Schär JG, Bachofen C, de Martin E, Portmann J, Stalder H, Schweizer M. Benefit of Bovine Viral Diarrhoea (BVD) Eradication in Cattle on Pestivirus Seroprevalence in Sheep. Front Vet Sci 2021; 8:681559. [PMID: 34671657 PMCID: PMC8520948 DOI: 10.3389/fvets.2021.681559] [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: 03/16/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Bovine viral diarrhoea virus (BVDV) and Border disease virus (BDV) are closely related pestiviruses of cattle and sheep, respectively. Both viruses may be transmitted between either species, but control programs are restricted to BVDV in cattle. In 2008, a program to eradicate bovine viral diarrhoea (BVD) in cattle was started in Switzerland. As vaccination is prohibited, the cattle population is now widely naïve to pestivirus infections. In a recent study, we determined that nearly 10% of cattle are positive for antibodies to BDV. Here, we show that despite this regular transmission of BDV from small ruminants to cattle, we could only identify 25 cattle that were persistently infected with BDV during the last 12 years of the eradication program. In addition, by determining the BVDV and BDV seroprevalence in sheep in Central Switzerland before and after the start of the eradication, we provide evidence that BVDV is transmitted from cattle to sheep, and that the BVDV seroprevalence in sheep significantly decreased after its eradication in cattle. While BDV remains endemic in sheep, the population thus profited at least partially from BVD eradication in cattle. Importantly, on a national level, BVD eradication does not appear to be generally derailed by the presence of pestiviruses in sheep. However, with every single virus-positive cow, it is necessary to consider small ruminants as a potential source of infection, resulting in costly but essential investigations in the final stages of the eradication program.
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Affiliation(s)
| | | | - Claudia Bachofen
- Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Elena de Martin
- Institute of Virology and Immunology, Bern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Jasmine Portmann
- Institute of Virology and Immunology, Bern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Hanspeter Stalder
- Institute of Virology and Immunology, Bern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Matthias Schweizer
- Institute of Virology and Immunology, Bern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
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2
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Campbell E, McConville J, Clarke J, Donaghy A, Moyce A, Byrne AW, Verner S, Strain S, McKeown IM, Borne P, Guelbenzu-Gonzalo M. Pestivirus apparent prevalence in sheep and goats in Northern Ireland: A serological survey. Vet Rec 2021; 188:e1. [PMID: 34651766 DOI: 10.1002/vetr.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Bovine viral diarrhoea virus (BVDV) and border disease virus (BDV) can cause significant health problems in ruminants and economic impacts for farmers. The aim of this study was to evaluate pestivirus exposure in Northern Ireland sheep and goat flocks, and to compare findings with a previous study from the region. METHODS Up to 20 animals were sampled from 188 sheep and 9 goat flocks (n = 3,418 animals; 3,372 sheep and 46 goats) for pestivirus antibodies. Differentiation of the causative agent in positive samples was inferred using serum neutralisation. Abortion samples from 177 ovine cases were tested by BVDV reverse-transcription polymerase chain reaction and antigen ELISA. RESULTS Apparent animal and flock (one antibody positive animal within a flock) prevalence was 1.7% and 17.3%, respectively, a statistically significant drop in apparent prevalence since a survey in 1999. 52.6% of samples testing positive had higher antibody titres to BVDV than to BDV. Of the ovine abortion samples, only one positive foetal fluid sample was detected by ELISA. CONCLUSION The present study found that, since 1999, there has been a decrease in apparent animal and flock prevalence of 3.7 and 12.8 percentage points respectively, suggesting pestivirus prevalence has decreased across Northern Ireland between 1999 and 2018.
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Affiliation(s)
- Emma Campbell
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - James McConville
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - Joe Clarke
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - Aoibheann Donaghy
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - Asa Moyce
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - Andrew W Byrne
- One-Health Scientific Support Unit, SAT Division, Department of Agriculture, Fisheries Food and Marine, Dublin, Ireland
| | - Sharon Verner
- Animal Health and Welfare Northern Ireland, Dungannon, UK
| | - Sam Strain
- Animal Health and Welfare Northern Ireland, Dungannon, UK
| | | | - Paul Borne
- Disease Surveillance and Investigation Branch, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
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3
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Non-Bovine Species and the Risk to Effective Control of Bovine Viral Diarrhoea (BVD) in Cattle. Pathogens 2021; 10:pathogens10101263. [PMID: 34684212 PMCID: PMC8540666 DOI: 10.3390/pathogens10101263] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 12/02/2022] Open
Abstract
Bovine viral diarrhoea virus (BVDV) is an economically important and highly prevalent virus of domestic cattle. Infections with BVDV may lead to both, reproductive and immunological effects that can result in widespread calf losses and increased susceptibility to diseases, such as mastitis and respiratory disease. While BVDV is generally considered to be host specific, it and other Pestivirus species, such as Border disease virus (BDV) in sheep, have been shown to be infecting species other than those from which they were originally isolated from. Recently BVDV was placed on the OIE’s list of notifiable disease and control and eradication programmes for BVDV have been developed throughout much of Europe, the United States, and the United Kingdom. While some countries, including Sweden and Ireland have successfully implemented eradication programmes, other countries such as New Zealand and Australia are still in the early stages of BVDV control. Despite effective control methods, incursions of BVDV into previously cleared herds still occur. While the cause of these incursions is often due to lapses in control methods, the ability of ruminant pestiviruses to infect species other than cattle poses the question as to whether non-bovine species could be impeding the success of BVDV eradication and control. As such, the aim of this review is to make mention of what is known about the cross-species transmission of BVDV, BDV and other pestiviruses between cattle and non-bovine ungulate species and draw conclusions as to the risk non-bovine species pose to the successful control and eradication of BVDV from cattle.
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4
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Walz PH, Chamorro MF, M Falkenberg S, Passler T, van der Meer F, R Woolums A. Bovine viral diarrhea virus: An updated American College of Veterinary Internal Medicine consensus statement with focus on virus biology, hosts, immunosuppression, and vaccination. J Vet Intern Med 2020; 34:1690-1706. [PMID: 32633084 PMCID: PMC7517858 DOI: 10.1111/jvim.15816] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 12/01/2022] Open
Abstract
Control of bovine viral diarrhea virus (BVDV) in cattle populations across most of the world has remained elusive in spite of advances in knowledge about this viral pathogen. A central feature of virus perseverance in cattle herds is the unique mechanism of persistent infection. Managing BVDV infection in herds involves controlling persistently infected carrier animals using a multidimensional approach of vaccination, biosecurity, and identification of BVDV reservoirs. A decade has passed since the original American College of Veterinary Internal Medicine consensus statement on BVDV. While much has remained the same with respect to clinical signs of disease, pathogenesis of infection including persistent infection, and diagnosis, scientific articles published since 2010 have led to a greater understanding of difficulties associated with control of BVDV. This consensus statement update on BVDV presents greater focus on topics currently relevant to the biology and control of this viral pathogen of cattle, including changes in virus subpopulations, infection in heterologous hosts, immunosuppression, and vaccination.
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Affiliation(s)
- Paul H Walz
- College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
| | - Manuel F Chamorro
- College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
| | - Shollie M Falkenberg
- USDA Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA
| | - Thomas Passler
- College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
| | - Frank van der Meer
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Amelia R Woolums
- College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, USA
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5
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Kuca T, Passler T, Newcomer BW, Neill JD, Galik PK, Riddell KP, Zhang Y, Bayles DO, Walz PH. Changes Introduced in the Open Reading Frame of Bovine Viral Diarrhea Virus During Serial Infection of Pregnant Swine. Front Microbiol 2020; 11:1138. [PMID: 32587582 PMCID: PMC7298064 DOI: 10.3389/fmicb.2020.01138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 05/05/2020] [Indexed: 12/27/2022] Open
Abstract
Bovine viral diarrhea virus (BVDV) is one of the most economically important viruses of cattle, but this pathogen is also able to infect pigs, camelids, and a wide range of domestic and wild ruminants. BVDV isolates circulating in animal populations are genetically and antigenically highly diverse. Acute BVDV infections in cattle cause the introduction of many substitutions in the viral genome. Serial infection of pregnant sheep with a BVDV-1b isolate of bovine origin was also associated with great numbers of substitutions. To our knowledge, genomic changes arising during BVDV infections in swine have not been investigated. The purpose of this study was to investigate the changes occurring in the open reading frame (ORF) of BVDV during serial infection of pregnant swine with a BVDV isolate of bovine origin. The BVDV-1b isolate AU526 was serially passaged in six pregnant gilts, two of which gave birth to live piglets congenitally infected with BVDV. The complete ORF sequences of 14 BVDV isolates obtained from pregnant gilts and their piglets were determined. Their analysis revealed that serial transmission of AU526 in pregnant swine resulted in many genomic changes. All isolates of porcine origin shared 32 nucleotide and 12 amino acid differences with the virus inoculum AU526. These changes were detected after a single passage in pregnant swine and were conserved during the subsequent five passages. Amino acid changes occurred primarily in genomic regions encoding the BVDV structural proteins E2 and E rns . These results suggest that BVDV infections in pregnant swine may contribute significantly to the genetic variability of BVDV and lead to the appearance of adaptive changes.
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Affiliation(s)
- Thibaud Kuca
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Thomas Passler
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Benjamin W Newcomer
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - John D Neill
- Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, United States
| | - Patricia K Galik
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Kay P Riddell
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Yijing Zhang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, United States
| | - Paul H Walz
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
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6
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Russell GC, Zadoks RN, Willoughby K, Bachofen C. Bovine viral diarrhoea virus loses quasispecies diversity rapidly in culture. Microb Genom 2020; 6:e000343. [PMID: 32160141 PMCID: PMC7276709 DOI: 10.1099/mgen.0.000343] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/07/2020] [Indexed: 12/25/2022] Open
Abstract
Bovine viral diarrhoea (BVD) is an important disease of cattle, with significant impacts on animal health and welfare. The wide host range of the causative pestiviruses may lead to formation of virus reservoirs in other ruminant or wildlife species, presenting a concern for the long-term success of BVD eradication campaigns. It is likely that the quasispecies nature of these RNA viruses contributes to their interspecies transmission by providing genetic plasticity. Understanding the spectrum of sequence variants present in persistently infected (PI) animals is, therefore, essential for studies of virus transmission. To analyse quasispecies diversity without amplification bias, we extracted viral RNA from the serum of a PI cow, and from cell culture fluid after three passages of the same virus in culture, to produce cDNA without amplification. Sequencing of this material using Illumina 250 bp paired-read technology produced full-length virus consensus sequences from both sources and demonstrated the quasispecies diversity of this pestivirus A genotype 1a field strain within serum and after culture. We report the distribution and diversity of over 800 SNPs and provide evidence for a loss of diversity after only three passages in cell culture, implying that cultured viruses cannot be used to understand quasispecies diversity and may not provide reliable molecular markers for source tracing or transmission studies. Additionally, both serum and cultured viruses could be sequenced as a set of 25 overlapping PCR amplicons that demonstrated the same consensus sequences and the presence of many of the same quasispecies variants. The observation that aspects of the quasispecies structure revealed by massively parallel sequencing are also detected after PCR and Sanger sequencing suggests that this approach may be useful for small or difficult to analyse samples.
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Affiliation(s)
- George C. Russell
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Ruth N. Zadoks
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
- Present address: Sydney School of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Kim Willoughby
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Claudia Bachofen
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
- Present address: Institute of Virology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zürich, Switzerland
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7
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Shi H, Leng C, Xu Q, Shi H, Sun S, Kan Y, Yao L. Characterization of a Pestivirus H isolate originating from goats. Virus Genes 2018; 54:603-607. [PMID: 29909436 DOI: 10.1007/s11262-018-1579-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/30/2018] [Indexed: 10/14/2022]
Abstract
Natural Pestivirus H infections in cattle have been reported worldwide; however, only a few cases of Pestivirus H have been described in non-bovine ruminants such as goats. A new Pestivirus H HN1507 strain was isolated from an infected goat in 2015 and the genome sequence was determined. The full-length genome sequence was 12,556 nucleotides. Phylogenetic analysis, based on the complete genome and Npro fragments, revealed that the isolate belonged to Pestivirus H and was closely related to strains from Italy. Two unique amino acid substitutions were found in the C-terminal of the E2 protein. To the best of our knowledge, this is first report determining the complete genome of a Pestivirus H strain from goat.
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Affiliation(s)
- Hongfei Shi
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China
| | - Chaoliang Leng
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China
| | - Qian Xu
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China
| | - Hongling Shi
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China
| | - Shiyu Sun
- Liaoning Center for Animal Disease Control and Prevention, Shenyang, People's Republic of China
| | - Yunchao Kan
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China.
| | - Lunguang Yao
- Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Libratory of Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China.
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8
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Kuca T, Passler T, Newcomer BW, Neill JD, Galik PK, Riddell KP, Zhang Y, Walz PH. Identification of Conserved Amino Acid Substitutions During Serial Infection of Pregnant Cattle and Sheep With Bovine Viral Diarrhea Virus. Front Microbiol 2018; 9:1109. [PMID: 29928264 PMCID: PMC5998738 DOI: 10.3389/fmicb.2018.01109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/09/2018] [Indexed: 11/13/2022] Open
Abstract
Bovine viral diarrhea virus (BVDV) is an economically important pathogen of cattle that can also infect a wide range of domestic and wild species including sheep, goats, deer, camelids, and pigs. BVDV isolates are genetically highly diverse and previous work demonstrated that many substitutions were introduced in the viral genome during acute infections in cattle. In contrast, only limited information exists regarding changes occurring during BVDV infections in species other than cattle. The purpose of this study was to determine the changes introduced in the open reading frame (ORF) of the BVDV genome during serial infection of pregnant cattle and sheep with an isolate of bovine origin. Serial experimental inoculations were performed in six pregnant heifers and six pregnant ewes using BVDV-1b isolate AU526 in the first heifer and ewe, and serum from the preceding acutely infected dam thereafter. Complete ORF sequences were determined for 23 BVDV-1b isolates including AU526, one isolate from each pregnant dam, and one isolate from each BVDV-positive offspring born to these dams. Sequence comparison revealed that greater numbers of substitutions occurred during serial infection of pregnant sheep than of pregnant cattle. Furthermore, multiple host-specific amino acid changes were gradually introduced and conserved. These changes were more abundant in ovine isolates and occurred primarily in the E2 coding region. These results suggest that BVDV infections in heterologous species may serve as a significant source of viral genetic diversity and may be associated with adaptive changes.
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Affiliation(s)
- Thibaud Kuca
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Thomas Passler
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Benjamin W. Newcomer
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - John D. Neill
- Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, United States
| | - Patricia K. Galik
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Kay P. Riddell
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Yijing Zhang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Paul H. Walz
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
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9
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Evans CA, Hemmatzadeh F, Reichel MP, Cockcroft PD. Natural transmission of bovine viral diarrhoea virus-1c from a persistently infected neonate lamb to naïve sheep and cattle. Vet Rec 2018; 182:352. [DOI: 10.1136/vr.104468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 11/09/2017] [Accepted: 01/21/2018] [Indexed: 11/03/2022]
Affiliation(s)
- Caitlin Alexandra Evans
- School of Animal and Veterinary Sciences, University of Adelaide-Roseworthy Campus; Roseworthy South Australia Australia
| | - Farhid Hemmatzadeh
- School of Animal and Veterinary Sciences, University of Adelaide-Roseworthy Campus; Roseworthy South Australia Australia
| | - Michael P Reichel
- College of Veterinary Medicine and Life Sciences, City University of Hong Kong; Kowloon Hong Kong
| | - Peter D Cockcroft
- School of Animal and Veterinary Sciences, University of Adelaide-Roseworthy Campus; Roseworthy South Australia Australia
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10
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Identification of amino acid changes in the envelope glycoproteins of bovine viral diarrhea viruses isolated from alpaca that may be involved in host adaptation. Vet Microbiol 2015; 179:299-303. [PMID: 26072370 DOI: 10.1016/j.vetmic.2015.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 05/22/2015] [Accepted: 06/04/2015] [Indexed: 11/22/2022]
Abstract
Bovine viral diarrhea viruses (BVDV) are most commonly associated with infections of cattle. However, BVDV are often isolated from closely related ruminants with a number of BVDV-1b viruses being isolated from alpacas that were both acutely and persistently infected. The complete nucleotide sequence of the open reading frame of eleven alpaca-adapted BVDV isolates and the region encoding the envelope glycoproteins of an additional three isolates were determined. With the exception of one, all alpaca isolates were >99.2% similar at the nucleotide level. The Hercules isolate was more divergent, with 95.7% sequence identity to the other viruses. Sequence similarity of the 14 viruses indicated they were isolates of a single BVDV strain that had adapted to and were circulating through alpaca herds. Hercules was a more distantly related strain that has been isolated only once in Canada and represented a separate adaptation event that possessed the same adaptive changes. Comparison of amino acid sequences of alpaca and bovine-derived BVDV strains revealed three regions with amino acid sequences unique to all alpaca isolates. The first contained two small in-frame deletions near the N-terminus of the E2 glycoprotein. The second was found near the C-terminus of the E2 protein where four altered amino acids were located within a 30 amino acid domain that participates in E2 homodimerization. The third region contained three variable amino acids in the C-terminus of the E(rns) within the amphipathic helix membrane anchor. These changes were found in the polar side of the amphipathic helix and resulted in an increased charge within the polar face. Titration of bovine and alpaca viruses in both bovine and alpaca cells indicated that with increased charge in the amphipathic helix, the ability to infect alpaca cells also increased.
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11
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Bachofen C, Grant DM, Willoughby K, Zadoks RN, Dagleish MP, Russell GC. Experimental infection of rabbits with bovine viral diarrhoea virus by a natural route of exposure. Vet Res 2014; 45:34. [PMID: 24690167 PMCID: PMC4234416 DOI: 10.1186/1297-9716-45-34] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 03/07/2014] [Indexed: 11/10/2022] Open
Abstract
Bovine viral diarrhoea virus (BVDV) is an important pathogen of cattle that can naturally infect a wide range of even-toed ungulates. Non-bovine hosts may represent reservoirs for the virus that have the potential to hamper BVDV eradication programs usually focused on cattle. Rabbits are very abundant in countries such as the United Kingdom or Australia and are often living on or near livestock pastures. Earlier reports indicated that rabbits can propagate BVDV upon intravenous exposure and that natural infection of rabbits with BVDV may occur but experimental proof of infection of rabbits by a natural route is lacking. Therefore, New Zealand White rabbits were exposed to a Scottish BVDV field strain intravenously, oro-nasally and by contaminating their hay with virus. None of the animals showed any clinical signs. However, the lymphoid organs from animals sacrificed at day five after exposure showed histological changes typical of transient infection with pestivirus. Most organ samples and some buffy coat samples were virus positive at day five but saliva samples remained negative. Development of antibodies was observed in all intravenously challenged animals, in all of the nebulised group and in four of six animals exposed to contaminated hay. To our knowledge this is the first report of BVDV propagation in a species other than ruminants or pigs after exposure to the virus by a natural route. However, to assess the role of rabbits as a potential reservoir for BVDV it remains to be determined whether persistent infection caused by intra-uterine infection is possible and whether BVDV is circulating in wild rabbit populations.
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Affiliation(s)
| | | | | | | | | | - George C Russell
- Moredun Research Institute, Pentlands Science Park, Penicuik EH26 0PZ, UK.
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12
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Braun U, Reichle SF, Reichert C, Hässig M, Stalder HP, Bachofen C, Peterhans E. Sheep persistently infected with Border disease readily transmit virus to calves seronegative to BVD virus. Vet Microbiol 2013; 168:98-104. [PMID: 24315041 DOI: 10.1016/j.vetmic.2013.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/04/2013] [Accepted: 11/04/2013] [Indexed: 11/27/2022]
Abstract
Bovine viral diarrhea- and Border disease viruses of sheep belong to the highly diverse genus pestivirus of the Flaviviridae. Ruminant pestiviruses may infect a wide range of domestic and wild cloven-hooved mammals (artiodactyla). Due to its economic importance, programs to eradicate bovine viral diarrhea are a high priority in the cattle industry. By contrast, Border disease is not a target of eradication, although the Border disease virus is known to be capable of also infecting cattle. In this work, we compared single dose experimental inoculation of calves with Border disease virus with co-mingling of calves with sheep persistently infected with this virus. As indicated by seroconversion, infection was achieved only in one out of seven calves with a dose of Border disease virus that was previously shown to be successful in calves inoculated with BVD virus. By contrast, all calves kept together with persistently infected sheep readily became infected with Border disease virus. The ease of viral transmission from sheep to cattle and the antigenic similarity of bovine and ovine pestiviruses may become a problem for demonstrating freedom of BVD by serology in the cattle population.
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Affiliation(s)
- U Braun
- Department of Farm Animals, University of Zurich, Winterthurer-strasse 260, CH-8057 Zurich, Switzerland
| | - S F Reichle
- Department of Farm Animals, University of Zurich, Winterthurer-strasse 260, CH-8057 Zurich, Switzerland
| | - C Reichert
- Department of Farm Animals, University of Zurich, Winterthurer-strasse 260, CH-8057 Zurich, Switzerland
| | - M Hässig
- Department of Farm Animals, University of Zurich, Winterthurer-strasse 260, CH-8057 Zurich, Switzerland
| | - H P Stalder
- Institute of Veterinary Virology, University of Bern, Länggass-Str. 122, P.O. Box 8644, CH-3001 Bern, Switzerland
| | - C Bachofen
- Institute of Veterinary Virology, University of Bern, Länggass-Str. 122, P.O. Box 8644, CH-3001 Bern, Switzerland
| | - E Peterhans
- Institute of Veterinary Virology, University of Bern, Länggass-Str. 122, P.O. Box 8644, CH-3001 Bern, Switzerland.
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13
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Abstract
Pestiviruses cause economically important diseases among domestic ruminants and pigs, but they may also infect a wide spectrum of wild species of even-toed ungulates (Artiodactyla). Bovine viral diarrhea virus (BVDV) and Border disease virus of sheep infect their hosts either transiently or persistently. Cellular and humoral immunotolerance to the infecting strain is a unique feature of persistent infection (PI) by ruminant pestiviruses. Persistence, caused by transplacental infection early in fetal development, depends on virally encoded interferon antagonists that inactivate the host's innate immune response to the virus without globally interfering with its function against other viruses. At epidemiological equilibrium, approximately 1-2% of animals are PI. Successful BVDV control programs show that removal of PI animals results in viral extinction in the host population. The nucleotide sequences of ruminant pestiviruses change little during persistent infection. Nevertheless, they display large heterogeneity, pointing to a long history of virus-host coevolution in which avirulent strains are more successful.
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Affiliation(s)
- Matthias Schweizer
- Institute of Veterinary Virology, University of Bern, CH-3001 Bern, Switzerland; ,
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14
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Bachofen C, Vogt HR, Stalder H, Mathys T, Zanoni R, Hilbe M, Schweizer M, Peterhans E. Persistent infections after natural transmission of bovine viral diarrhoea virus from cattle to goats and among goats. Vet Res 2013; 44:32. [PMID: 23675947 PMCID: PMC3660168 DOI: 10.1186/1297-9716-44-32] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/23/2013] [Indexed: 11/10/2022] Open
Abstract
Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle worldwide. Infection of a pregnant animal may lead to persistent infection of the foetus and birth of a persistently infected (PI) calf that sheds the virus throughout its life. However, BVD viruses are not strictly species specific. BVDV has been isolated from many domesticated and wild ruminants. This is of practical importance as virus reservoirs in non-bovine hosts may hamper BVDV control in cattle. A goat given as a social companion to a BVDV PI calf gave birth to a PI goat kid. In order to test if goat to goat infections were possible, seronegative pregnant goats were exposed to the PI goat. In parallel, seronegative pregnant goats were kept together with the PI calf. Only the goat to goat transmission resulted in the birth of a next generation of BVDV PI kids whereas all goats kept together with the PI calf aborted. To our knowledge, this is the first report which shows that a PI goat cannot only transmit BVD virus to other goats but that such transmission may indeed lead to the birth of a second generation of PI goats. Genetic analyses indicated that establishment in the new host species may be associated with step-wise adaptations in the viral genome. Thus, goats have the potential to be a reservoir for BVDV. However, the PI goats showed growth retardation and anaemia and their survival under natural conditions remains questionable.
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Affiliation(s)
- Claudia Bachofen
- Institute of Veterinary Virology, University of Bern, Länggassstr, 122, P,O, Box 8466, CH-3001 Bern, Switzerland.
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15
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Giammarioli M, La Rocca SA, Steinbach F, Casciari C, De Mia GM. Genetic and antigenic typing of border disease virus (BDV) isolates from Italy reveals the existence of a novel BDV group. Vet Microbiol 2011; 147:231-6. [DOI: 10.1016/j.vetmic.2010.06.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 06/16/2010] [Accepted: 06/29/2010] [Indexed: 11/24/2022]
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16
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Mudry M, Meylan M, Regula G, Steiner A, Zanoni R, Zanolari P. Epidemiological study of pestiviruses in South American camelids in Switzerland. J Vet Intern Med 2010; 24:1218-23. [PMID: 20726946 DOI: 10.1111/j.1939-1676.2010.0577.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND In the context of the ongoing eradication campaign for bovine viral diarrhea virus (BVDV) in cattle in Switzerland, the role of South American camelids (SAC) as a possible virus reservoir needed to be evaluated. OBJECTIVE To assess and characterize the prevalence of pestivirus infections in SAC in Switzerland. ANIMALS Serum samples collected from 348 animals (40 herds) in 2008 and from 248 animals (39 herds) in 2000 were examined for antibodies against pestiviruses and for the presence of BVDV viral RNA. METHODS Cross-sectional study using stratified, representative herd sampling. An indirect BVDV-ELISA was used to analyze serum samples for pestivirus antibodies, and positive samples underwent a serum neutralization test (SNT). Real-time RT-PCR to detect pestiviral RNA was carried out in all animals from herds with at least 1 seropositive animal. RESULTS In 2008, the overall prevalence of animals positive for antibodies (ELISA) and pestiviral RNA or was 5.75 and 0%, respectively. In 2000, the corresponding prevalences were 3.63 and 0%, respectively. The seroprevalences (SNT) for BVDV, border disease virus or undetermined pestiviruses were estimated to be 0, 1.73, and 4.02% in 2008, and 0.40, 1.21, and 2.02% in 2000, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE At the present time, SAC appear to represent a negligible risk of re-infection for the BVDV eradication program in cattle in Switzerland.
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Affiliation(s)
- M Mudry
- Clinic for Ruminants, Vetsuisse Faculty of the University of Berne, Berne, Switzerland
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17
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Pestivirus infection in sheep and goats in West Austria. Vet J 2009; 186:342-6. [PMID: 20042353 DOI: 10.1016/j.tvjl.2009.09.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 09/01/2009] [Accepted: 09/04/2009] [Indexed: 11/23/2022]
Abstract
Blood samples from 3112 sheep (185 flocks) and 1196 goats (163 flocks) from the Western region of Austria were tested for pestivirus-specific RNA. In this area, communal Alpine pasturing of sheep, cattle and goats is an important part of farming. The prevalence of sheep persistently-infected (PI) with pestivirus was 0.32% (10 animals) and the PI animals originated from five flocks (2.7% of those investigated). In goats, only one PI animal (0.08%) was detected. Sequence analysis of the 5'-end untranslated region (UTR) revealed that the strains of Border disease virus (BDV) detected were closely related to genotype 3 but the PI animals did not show any clinical signs of Border disease. The goat was PI with bovine viral diarrhoea virus-1 (BVDV-1). On one farm a high abortion rate among sheep had been observed 1year before the study was carried out but the other farms did not show any evidence of reproductive failures. Pestiviruses are endemic in small ruminants in some Alpine regions of Austria and PI healthy animals as described here have a key epidemiological role. A successful BVDV eradication programme in Austria will create highly pestivirus-susceptible cattle populations. Sheep and goats present a high risk for the reintroduction of pestiviruses to cattle herds because they are less likely to be considered to be PI. The results underline the need for the immediate consideration of small ruminants in eradication programmes.
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Antigenic and genetic characterisation of border disease viruses isolated from UK cattle. Vet Microbiol 2009; 141:208-15. [PMID: 19781869 DOI: 10.1016/j.vetmic.2009.09.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 08/18/2009] [Accepted: 09/04/2009] [Indexed: 11/21/2022]
Abstract
Available empirical data on the natural occurrence of ruminant pestiviruses has shown that in cattle, bovine viral diarrhoea virus (BVDV) is nearly exclusively found, whereas both border disease virus (BDV) and BVDV can be isolated from sheep. During routine genetic typing of pestivirus RNA from UK cattle diagnosed as BVDV positive between 2006 and 2008, five samples that were classified as BDV positive yielded positive virus isolates in cell cultures. The samples originated from animals that had shown signs typical for BVD. Phylogenetic analysis of the bovine BDVs showed that two belonged to the BDV-1a group and three to the BDV-1b group, thereby matching the genetic diversity seen for previously described UK ovine BDVs. Antigenic typing with a set of monoclonal antibodies (MABs) showed that all bovine BDVs lacked one or more epitopes conserved among ovine BDV-1 isolates, and that they had gained reactivity with at least one BVDV-1 specific MAB. Serial passaging of two of the virus isolates in ovine cell cultures did not change the epitope expression pattern. These findings suggest that the presumed natural resistance of cattle against infection with BDV no longer holds. A consequence of this is that BVD diagnostic assays should be checked for their ability to also detect BDV, and also highlights the need for monitoring of the BDV status in sheep that may be in contact with cattle in areas with organised BVD control programmes.
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Uttenthal A, Hoyer MJ, Grøndahl C, Houe H, van Maanen C, Rasmussen TB, Larsen LE. Vertical transmission of bovine viral diarrhoea virus (BVDV) in mousedeer (Tragulus javanicus) and spread to domestic cattle. Arch Virol 2006; 151:2377-87. [PMID: 16835699 DOI: 10.1007/s00705-006-0818-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2006] [Accepted: 06/07/2006] [Indexed: 11/25/2022]
Abstract
This study investigates the transmission of bovine viral diarrhoea virus (BVDV) 1f from a persistently infected (PI) lesser Malayan mousedeer to two bovine calves. Different contact routes to two calves were analysed: 1) aerosol contact between two adjacent pens without physical contact; 2) indirect contact by use of common utensils; 3) direct nose-to-nose contact for 30 seconds. One of the calves was infected either by aerosol or indirect contact. The virus sequence in 247 nucleotides in the 5'-UTR was 100% identical in mousedeer and calf. To elucidate the distribution of BVDV within the affected mousedeer family the captive population in a Zoo was analysed. The maternal line of PI animals was maintained, whereas a PI male was able to reproduce and have a non-PI calf. As a consequence of this, six female PI mousedeer were killed; subsequent autopsies did not reveal any lesions. Sequencing mousedeer BVD virus in the E2 region (420 nucleotides) through 4 generations showed only 7 mutations, which were maintained from mother to offspring.
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Affiliation(s)
- A Uttenthal
- Department of Virology, Danish Institute for Food and Veterinary Research, Lindholm, Kalvehave, Denmark.
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20
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Uttenthal A, Grøndahl C, Hoyer MJ, Houe H, van Maanen C, Rasmussen TB, Larsen LE. Persistent BVDV infection in mousedeer infects calves. Prev Vet Med 2005; 72:87-91; discussion 215-9. [PMID: 16213611 DOI: 10.1016/j.prevetmed.2005.08.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 03/01/2005] [Accepted: 05/25/2005] [Indexed: 11/16/2022]
Abstract
Bovine virus diarrhoea virus (BVDV)-1f was isolated from a Lesser Malayan Mousedeer in Copenhagen Zoo during a routine screening. Analysis of animals related to the Copenhagen mousedeer revealed that its mother and all siblings were virus positive, a pattern also seen for persistently infected (PI) cattle. BVDV could be transmitted from the PI mousedeer to a calf after indirect contact. The host spectrum for BVDV seems to be even wider than expected; the implications for BVDV control are discussed.
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Affiliation(s)
- Ase Uttenthal
- Danish Institute for Food and Veterinary Research, Lindholm, DK-4771 Kalvehave, Denmark.
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21
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Swasdipan S, McGowan M, Phillips N, Bielefeldt-Ohmann H. Pathogenesis of transplacental virus infection: pestivirus replication in the placenta and fetus following respiratory infection. Microb Pathog 2002; 32:49-60. [PMID: 11812211 DOI: 10.1006/mpat.2001.0480] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Although transplacental virus infections account for considerable morbidity and mortality in both animals and humans, very little is so far known about the pathways whereby virus reaches the conceptus, the subsequent virus-host interactions in the early phases of the infections, and the establishment of persistent non-lethal infection. Using a natural animal model we recently demonstrated that bovine pestivirus can spread from the site of infection to the ovine fetus within 72 h, despite the expression of interferon in the reproductive tract [1]. In the present study we demonstrate that pestivirus first establishes infection and spread within the allantoic and amniotic membranes and then the fetus, followed several days later by infection of the uterine glands. However, virus replication and spread within the fetus is, at least in part, controlled by fetal developmental factors. In fetuses less than 25 days of gestational age, the virus remains restricted to the bulbis cordis, the first brachial pouch and occasionally the aorta. Over the next few days the virus spreads to multiple tissues, in addition to becoming more widespread and pronounced within the initially infected tissues. A potential role for the binucleated cells of the allantochorion in the spread of the virus from the fetal to the maternal tissues was also found. These cells expressed high levels of viral antigen just prior to and during the time period in which virus antigen became detectable in the epithelial cells of the uterine glands, in endothelial cells of uterine vessels and in scattered macrophage-like cells in the uterine stroma. Most likely this relatively late virus transfer is inconsequential for the mother, since it occurs at a time when a maternal virus-specific antibody response is becoming measurable. This is in contrast to the fetus, where the infection will have established itself widely prior to the development of lymphoid tissues and a functional immune response, thus setting the scenario for development of specific tolerance to the persisting virus.
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MESH Headings
- Animals
- Antibodies, Viral/blood
- Antigens, Viral/analysis
- Antigens, Viral/blood
- Bovine Virus Diarrhea-Mucosal Disease/pathology
- Bovine Virus Diarrhea-Mucosal Disease/transmission
- Bovine Virus Diarrhea-Mucosal Disease/virology
- Cattle
- DNA, Viral/genetics
- Diarrhea Viruses, Bovine Viral/genetics
- Diarrhea Viruses, Bovine Viral/growth & development
- Endometrium/pathology
- Endometrium/virology
- Female
- Fetal Diseases/pathology
- Fetal Diseases/virology
- Infectious Disease Transmission, Vertical
- Interferon Type I/biosynthesis
- Placenta Diseases/pathology
- Placenta Diseases/virology
- Pregnancy
- Pregnancy Complications, Infectious/pathology
- Pregnancy Complications, Infectious/virology
- Pregnancy Proteins/biosynthesis
- RNA, Viral/genetics
- Reverse Transcriptase Polymerase Chain Reaction/veterinary
- Sheep
- Sheep Diseases/pathology
- Sheep Diseases/transmission
- Sheep Diseases/virology
- Virus Replication
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Affiliation(s)
- Somchai Swasdipan
- School of Veterinary Science, University of Queensland, Brisbane, North Mymms, Qld 4072, Australia
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22
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de Smit AJ. Laboratory diagnosis, epizootiology, and efficacy of marker vaccines in classical swine fever: a review. Vet Q 2000; 22:182-8. [PMID: 11087126 DOI: 10.1080/01652176.2000.9695054] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
Detection of classical swine fever virus (CSFV) can be achieved by a range of assays of which the most commonly used are: immunohistochemical and virus culture techniques. New developments have enabled the detection of viral proteins by enzyme-linked immunosorbent assays (ELISAs) and the detection of the viral genome by RT- PCR. So far, laboratory findings show that the latter assays may supplement or replace the conventional techniques in the near future. The detection of serum antibody against structural and non-structural proteins of CSFV has been improved by developments in recombinant DNA techniques and has lead to a range of ELISAs. Although the characteristics of these ELISAs are excellent, positive results still need to be confirmed in the virus neutralization test. The available amount of sequence data enables diagnosticians to type strains of CSFV as different by comparing several parts of the genome. In some cases, this can provide conclusive evidence if a primary or secondary outbreak has been detected. Increased efforts focused on the retrieval of relevant data on the introduction of CSFV in a pig holding and the spread of CSFV in- and between pig holding(s) has generated more insight into the epizootiology of the disease. A successful control and eradication programme for classical swine fever (CSF) can consist of zoosanitary measures and/or vaccination. The latter can compromise the export of live pigs and pig products considerably unless marker vaccines have been used. Several studies were performed to determine the efficacy of an E2 subunit vaccine and live recombinant vaccine candidates. Firstly, we determined the 95% protective dose of an E2 subunit vaccine at 32 microg E2 per dosage after a single application. Further studies with a single administration of the subunit vaccine showed that: the vaccine was stable for a prolonged period after production, was able to reduce horizontal and vertical transmission of CSFV among vaccinated pigs, and provided protection for at least 6 months. An E(rns) antibody discriminatory assay was developed for use in combination with the subunit vaccine. Evaluation of the E(rns) ELISA showed that the sensitivity of the assay was lower than but that the specificity was equal to that of existing antibody assays. Two live recombinant marker vaccines were evaluated for the induction of clinical protection and reduction of transmission of CSFV shortly after vaccination. Results showed that these vaccines provided good clinical protection 1 week after a single vaccination. Research has shown that marker vaccines can be used in the future to support the control and eradication of CSFV.
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Affiliation(s)
- A J de Smit
- Institute for Animal Science and Health ID-Lelystad, National Reference Laboratory for Classical Swine Fever, The Netherlands
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23
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Fray MD, Supple EA, Morrison WI, Charleston B. Germinal centre localization of bovine viral diarrhoea virus in persistently infected animals. J Gen Virol 2000; 81:1669-73. [PMID: 10859371 DOI: 10.1099/0022-1317-81-7-1669] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Immunohistochemical analysis of peripheral lymph nodes from gnotobiotic calves persistently infected with bovine viral diarrhoea virus (BVDV) revealed extensive deposition of E(rns) and localization of the viral genome in the light zone of germinal centres. Viral antigen co-localized with immunoglobulin in the germinal centres and was shown to be extracellular. Despite the presence of viral antigen in germinal centres, circulating anti-BVDV antibody was not detected. These findings provide evidence that calves persistently infected with BVDV, in the absence of adventitious infection, can generate a B cell response to the persisting virus. The nature of the tolerance in calves persistently infected with BVDV is discussed in light of these findings.
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Affiliation(s)
- M D Fray
- Institute for Animal Health, Compton, Newbury RG20 7NN, UK
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Toth RL, Nettleton PF, McCrae MA. Expression of the E2 envelope glycoprotein of bovine viral diarrhoea virus (BVDV) elicits virus-type specific neutralising antibodies. Vet Microbiol 1999; 65:87-101. [PMID: 10078593 DOI: 10.1016/s0378-1135(98)00291-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A region of genome from the NADL strain of BVDV corresponding to the coding sequence for the E2 glycoprotein has been molecularly cloned using RT-PCR. The viral cDNA sequence was used to construct vaccinia virus recombinants that expressed either the entire E2 coding sequence or fragments of it. These recombinants were used to immunise mice of three H-2 haplotypes to investigate their ability to elicit a neutralising antibody response against BVDV. Sera from mice immunised with the recombinant expressing full length E2 contained high levels of virus neutralising antibodies that in addition to giving neutralisation of the homologous NADL strain were also able to neutralise the Oregon C24V reference strain. These sera failed to give any neutralisation of the Osloss reference strain providing evidence for the division of BVDV isolates into at least two distinct E2 serotypes. These results were confirmed in gnotobiotic lambs. Expression of E2 fragments revealed the presence of at least two distinct neutralising epitopes, one of which was localised within the carboxy terminal 90 amino acids of the protein.
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MESH Headings
- Animals
- Antibodies, Monoclonal
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Base Sequence
- Bovine Virus Diarrhea-Mucosal Disease/immunology
- Cattle
- Diarrhea Viruses, Bovine Viral/chemistry
- Diarrhea Viruses, Bovine Viral/genetics
- Diarrhea Viruses, Bovine Viral/immunology
- Gene Expression Regulation, Viral
- Germ-Free Life/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Neutralization Tests/veterinary
- Radioimmunoprecipitation Assay/veterinary
- Sequence Analysis, DNA
- Sheep
- Vaccination/veterinary
- Vaccines, Synthetic
- Vaccinia virus
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- R L Toth
- Department of Biological Sciences, University of Warwick, Coventry, UK
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