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Shawn Babiuk - One of the best experts on this subject based on the ideXlab platform.
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Potential of Using Capripoxvirus Vectored Vaccines Against Arboviruses in Sheep, Goats, and Cattle.
Frontiers in veterinary science, 2019Co-Authors: Mahder Teffera, Shawn BabiukAbstract:The genus capripoxvirus consists of sheeppox virus, Goatpox virus, and lumpy skin disease virus, which affect sheep, goats, and cattle, respectively. Together capripoxviruses cause significant economic losses to the sheep, goat, and cattle industry where these diseases are present. These diseases have spread into previously free bordering regions most recently demonstrated with the spread of lumpy skin disease virus into the Middle East, some Eastern European countries, and Russia. This recent spread has highlighted the transboundary nature of these diseases. To control lumpy skin disease virus, live attenuated viral vaccines are used in endemic countries as well as in response to an outbreak. For sheeppox and Goatpox, live attenuated viral vaccines are used in endemic countries; these diseases can also be contained through slaughter of infected animals to stamp out the disease. The thermostability, narrow host range, and ability of capripoxviruses to express a wide variety of antigens make capripoxviruses ideal vectors. The ability to immunize animals against multiple diseases simultaneously increases vaccination efficiency by decreasing the number of vaccinations required. Additionally, the use of capripoxvirus vectored vaccines allows the possibility of differentiating infected from vaccinated animals. Arboviruses such as bluetongue virus and Rift Valley fever viruses are also responsible for significant economic losses in endemic countries. In the case of Rift Valley fever virus, vaccination is not routinely practiced unless there is an outbreak making vaccination not as effective, therefore, incorporating Rift Valley fever vaccination into routine capripoxvirus vaccination would be highly beneficial. This review will discuss the potential of using capripoxvirus as a vector expressing protective arboviral antigens.
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Propagation of the virus in vitro.
Lumpy Skin Disease, 2018Co-Authors: Shawn BabiukAbstract:Capripoxviruses comprising sheeppox, Goatpox and lumpy skin disease virus (LSDV) have a tropism for epithelial cells. This tropism allows capripoxviruses to be propagated in a wide variety of cell types from cattle, goat and sheep origin with virus titres up to a titre of 106 TCID50 per ml. These cell types include cells from tissues, including the kidney, testes, adrenal, thyroid, skin and muscle. There are currently no cell culture systems which can differentiate lumpy skin disease from sheeppox and Goatpox. The tropism and the cytopathic effect for all the evaluated cells are identical between capripoxviruses.
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Vaccines Against LSD and Vaccination Strategies
Lumpy Skin Disease, 2018Co-Authors: Shawn BabiukAbstract:Since there are no drug treatments for lumpy skin disease (LSD), vaccination using live attenuated vaccines are used to control the disease. The main prerequisites of a good vaccine are safety and protection from infection. The safety of a vaccine is determined by the frequency and severity of the adverse reactions it might cause, by the probability of reversion to virulence and by its purity. Protection provided by a vaccine depends on the specific immunologic response it elicits and can be measured by its efficacy or effectiveness. The efficacy of a vaccine is represented by the percentage of morbidity prevented by vaccination. Since capripoxviruses are genetically similar and have no serotypes, it was previously suggested that the development of a single capripoxvirus vaccine to protect against all three species should be possible (Kitching 1983, 2003). However, currently there is no universal vaccine available. There are several reasons for this. One reason is that although capripoxvirus vaccines may be effective for a particular host, they may not be as effective in a different host due to being not fully attenuated, over attenuated and/or not immunogenic. This is due to the complex virus-host interactions which determine virulence as well as the immune response elicited. The quality control and production of the vaccines may not follow the guidelines provided by the good manufacturing practices (GMP) for biological products by the World Health Organization. An additional reason is the geographic distributions of sheeppox, Goatpox and LSD, which are partially different. There are countries which have only sheep- and/or Goatpox without LSD, countries which only have LSD and countries which have sheep- and/or Goatpox as well as LSD (Babiuk et al. 2008). Due to potential safety issues, affected countries will tend to use only those capripoxvirus vaccines containing viruses present in the country (Tuppurainen and Oura 2012). This has led to regulatory challenges to authorize the use of these vaccines in the country or region.
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Yemen and Vietnam capripoxviruses demonstrate a distinct host preference for goats compared with sheep.
Journal of General Virology, 2009Co-Authors: Shawn Babiuk, Timothy R Bowden, Geoff R Parkyn, John Copps, Brett Dalman, Dong Manh Hoa, Ngo Thanh Long, Xuan Bieu, David B BoyleAbstract:Sheeppox and Goatpox are caused by viruses that are members of the genus Capripoxvirus, and globally result in significant production losses. To improve the understanding of disease pathogenesis and evaluate host species preferences, sheep and goats were inoculated either with a capripoxvirus isolate from Yemen or from a recent outbreak in Vietnam. Blood, swabs and tissues were collected at various time points following experimental challenge and assessed for viral DNA content using real-time PCR and infectivity using virus isolation. The Yemen isolate was considerably more pathogenic in goats with 100 % mortality and morbidity compared with sheep with 0 % mortality and 100 % morbidity. The Vietnam isolate was also more pathogenic in goats with 100 % morbidity and an estimated 33 % mortality rate compared with mild morbidity and a 0 % mortality rate in sheep. Higher viral titres were observed in nasal, oral and conjunctival swabs from goats inoculated with either the Yemen or Vietnam isolate compared with those collected from sheep. Although the highest viral titres were detected in primary and secondary skin lesions in sheep and goats, the severity of clinical disease observed in each species varied according to the inoculum used. Whereas both the Yemen and Vietnam isolates clearly caused more severe disease in goats, the Yemen isolate was also moderately pathogenic in sheep. The Vietnam isolate, in contrast, caused only very mild disease in sheep. Limited DNA sequencing revealed ORF 074 of the Vietnam isolate to be identical to that of several Goatpox virus isolates from China, suggesting a possible Chinese origin.
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capripoxvirus tissue tropism and shedding a quantitative study in experimentally infected sheep and goats
Virology, 2008Co-Authors: Timothy R Bowden, Shawn Babiuk, Geoff R Parkyn, John Copps, David B BoyleAbstract:Sheeppox virus and Goatpox virus cause systemic disease in sheep and goats that is often associated with high morbidity and high mortality. To increase understanding of the pathogenesis of these diseases, we undertook quantitative time-course studies in sheep and goats following intradermal inoculation of Nigerian sheeppox virus or Indian Goatpox virus in their respective homologous hosts. Viremia, determined by virus isolation and real-time PCR, cleared within 2 to 3 weeks post inoculation. Peak shedding of viral DNA and infectious virus in nasal, conjunctival and oral secretions occurred between 10 and 14 days post inoculation, and persisted at low levels for up to an additional 3 to 6 weeks. Although gross lesions developed in multiple organ systems, highest viral titers were detected in skin and in discrete sites within oronasal tissues and gastrointestinal tract. The temporal distribution of infectious virus and viral DNA in tissues suggests an underlying pathogenesis that is similar to smallpox and monkeypox where greatest viral replication occurs in the skin. Our data demonstrate that capripoxvirus infections in sheep and goats provide additional and convenient models which are suitable not only for evaluation of poxvirus-specific vaccine concepts and therapeutics, but also study of poxvirus-host interactions.
Eeva S. M. Tuppurainen - One of the best experts on this subject based on the ideXlab platform.
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An HRM assay to differentiate sheeppox virus vaccine strains from sheeppox virus field isolates and other capripoxvirus species
Scientific Reports, 2019Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Francisco J. Berguido, Amel OmaniAbstract:Sheep poxvirus (SPPV), goat poxvirus (GTPV) and lumpy skin disease virus (LSDV) affect small ruminants and cattle causing sheeppox (SPP), Goatpox (GTP) and lumpy skin disease (LSD) respectively. In endemic areas, vaccination with live attenuated vaccines derived from SPPV, GTPV or LSDV provides protection from SPP and GTP. As live poxviruses may cause adverse reactions in vaccinated animals, it is imperative to develop new diagnostic tools for the differentiation of SPPV field strains from attenuated vaccine strains. Within the capripoxvirus (CaPV) homolog of the variola virus B22R gene, we identified a unique region in SPPV vaccines with two deletions of 21 and 27 nucleotides and developed a High-Resolution Melting (HRM)-based assay. The HRM assay produces four distinct melting peaks, enabling the differentiation between SPPV vaccines, SPPV field isolates, GTPV and LSDV. This HRM assay is sensitive, specific, and provides a cost-effective means for the detection and classification of CaPVs and the differentiation of SPPV vaccines from SPPV field isolates.
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General Description of Lumpy Skin Disease
Lumpy Skin Disease, 2018Co-Authors: Eeva S. M. TuppurainenAbstract:Lumpy skin disease (LSD) is endemic across most of the African continent, and since 2012 it has spread widely within the Middle East, Southeast Europe and the northern Caucasus. Lumpy skin disease virus (LSDV) shares the genus Capripoxvirus (CaPV) within the family Poxviridae (Buller et al. 2005) with sheeppox virus (SPPV) and Goatpox virus (GTPV).
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariame DiopAbstract:Background Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants’ production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains.
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology Journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariane DiopAbstract:Background: Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants' production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains. Results: A unique 84 base pair nucleotide deletion located between the DNA ligase gene and the VARV B22R homologue gene was found only in SPPV vaccines derived from the Romanian and Yugoslavian RM/65 strains and absent in SPPV field isolates originated from various geographical locations of Asia and Africa. In addition, we developed and evaluated a conventional PCR assay, exploiting the targeted intergenic region to differentiate SPPV vaccine virus from field isolates. The assay produced an amplicon size of 218 bp for the vaccine strains, while the SPPV field isolates resulted in a 302 bp PCR fragment. The assay showed good sensitivity and specificity, and the results were in full agreement with the sequencing data of the PCR amplicons. Conclusion: The developed assay is an improvement of currently existing diagnostic tools and, when combined with a capripox virus species-specific assay, will enhance SPP and GTP diagnosis and surveillance and facilitate epidemiological investigations in countries using live attenuated SPP vaccines. In addition, for laboratories with limited resources, the assay provides a simple and cost-effective alternative for sequencing.
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Review: Capripoxvirus Diseases: Current Status and Opportunities for Control
Transboundary and emerging diseases, 2015Co-Authors: Eeva S. M. Tuppurainen, Estelle Hildegard Venter, Joanna L. Shisler, G. Gari, G.a. Mekonnen, Nicholas Juleff, Nicholas A. Lyons, K. De Clercq, C. Upton, Timothy R BowdenAbstract:Lumpy skin disease, sheeppox and Goatpox are high-impact diseases of domestic ruminants with a devastating effect on cattle, sheep and goat farming industries in endemic regions. In this article, we review the current geographical distribution, economic impact of an outbreak, epidemiology, transmission and immunity of capripoxvirus. The special focus of the article is to scrutinize the use of currently available vaccines to investigate the resource needs and challenges that will have to be overcome to improve disease control and eradication, and progress on the development of safer and more effective vaccines. In addition, field evaluation of the efficacy of the vaccines and the genomic database available for poxviruses are discussed.
Gnanavel Venkatesan - One of the best experts on this subject based on the ideXlab platform.
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Capripoxvirus and Orf Virus
Livestock Diseases and Management, 2020Co-Authors: Gnanavel Venkatesan, Amit Kumar, Veerakyathappa Bhanuprakash, Vinayagamurthy Balamurugan, Raj Kumar SinghAbstract:Capripox infections of small ruminants, namely Goatpox and sheeppox, are OIE notifiable and transboundary animal diseases. Goatpox and sheeppox are prevalent in some parts of Africa, the Middle East, and Asia with occasional outbreaks in regions of Europe. The etiological agents, Goatpox virus (GTPV) and sheeppox virus (SPPV), are indistinguishable serologically. However, they are differentiated by some of the molecular techniques. The diseases are characterized by fever, papules, nodular lesions on the skin, and sometimes internal organs and lymphadenopathy with high morbidity and mortality in affected animals. Contagious ecthyma (orf) is an economically important contagious disease of sheep, goat, and other ruminants with worldwide distribution. It is a local eruptive skin disease characterized by proliferative lesions on mouth and muzzle. The disease has zoonotic importance causing localized lesions in humans. The orf virus (ORFV) is the causative agent of this skin infection belongs to the genus Parapoxvirus. Also, it possesses the capacity to re-infect the host due to its epitheliotropic niche and encoded immunomodulators. Goatpox, sheeppox, and orf infections pose serious economic threat to the agricultural sector and livelihood of the farmers in endemic regions with a major impact on international trade. A prompt diagnosis along with well-planned vaccination and effective bio-security measures are main control measures to contain the infection in any endemic region. Development of recombinant protein-based serodiagnostic assays and rapid pen-side diagnostics that allow differentiation of GTPV, SPPV, and ORFV is the need of the hour for improved disease control.
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Comparative sequence and structural analysis of the ORF095 gene, a vaccinia virus A4L homolog of capripoxvirus in sheep and goats
Archives of Virology, 2020Co-Authors: Aparna Madhavan, Gnanavel Venkatesan, Amit Kumar, Sargam Arya, A. B. PandeyAbstract:Sheeppox and Goatpox are important transboundary animal viral diseases of sheep and goats caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively, of the genus Capripoxvirus , family Poxviridae . Among the proteins encoded by the capripoxvirus (CaPV) genome, ORF095 (vaccinia virus A4L homolog) is an immunodominant virion core protein that plays a pivotal role in virus assembly and morphogenesis. In the present study, sequence analysis of the ORF095 genes of 27 SPPV and GTPV isolates or field samples from different geographical regions of India was performed, and structure was prediction was done by homology modeling. A multiple sequence alignment of different CaPV isolates revealed that CaPV-A4L is highly conserved, with several species-specific signature residues, namely A93, A216, A315, G136 and G146 in GTPV, G47, A63, A168 and A276 in SPPV, and G48 and C98 in lumpy skin disease virus (LSDV). Phylogenetically, the CaPV isolates were separated into three major clusters, GTPV, SPPV and LSDV, based on the complete coding sequence of the CaPV-A4L gene. Genus-specific clustering of poxviruses was observed in phylogenetic analysis based on A4L protein homologs of chordopoxviruses. A secondary structure prediction showed the presence of six α-helices and one β-sheet as well as some coils. The signature residues identified here are potentially useful for genotyping, and the predicted characteristics of the CaPV-A4L protein make it an ideal candidate for use as an immunogenic or diagnostic antigen for the development of immunoassays in the sero-evaluation of CaPV in target hosts.
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Genetic studies of terminal regions of vaccine and field isolates of capripoxviruses
Infection genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 2019Co-Authors: Ashwini Rameshrao Chaple, Gnanavel Venkatesan, Amit Kumar, D. Muthuchelvan, Soumajit Sarkar, S. Chandrasekar, Sanchay Kumar Biswas, Karam Chand, Muthannan Andavar RamakrishnanAbstract:Abstract Sheeppox and Goatpox are two of the most important diseases associated with significant economic loss and impact on animal trade. In spite of the use of vaccines, outbreaks are being reported on several occasions. Therefore, deciphering the host specificity and virulence of sheeppox virus (SPPV) and Goatpox virus (GTPV) is important in developing effective vaccines. It is opined that genes located in the terminal regions play a major role in determining host range and/or virulence. In the present study, nine isolates (6 GTPV and 3 SPPV; included both vaccine and virulent viruses) were genetically characterized by targeting 11 genes (7 host-range and 4 virulence genes) which are located in the terminal regions of capripoxviruses. In the genetic analyses, it was observed that there are several nucleotide and amino acid signatures which are specific for either SPPV or GTPV. However, surprisingly, none of the 11 genes could be able to differentiate the vaccine and field viruses of GTPV and SPPV. Our study indicates that the genes of the terminal regions may have a role in determining the host-specificity but the involvemet in determinatin of virulence/attenuation is not certain at least for the isolates used in the current study. Therefore, it is likely that some other genes located in terminal/central regions may also play a role in determination of virulence and pathogenesis which needs to be confirmed by whole-genome sequencing of several vaccine and virulent viruses.
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Goatpox outbreak at a high altitude goat farm of mizoram possibility of wild life spill over to domestic goat population
VirusDisease, 2018Co-Authors: D P Bora, Gnanavel Venkatesan, Samsun Neher, Puja Mech, N N Barman, Esther Ralte, D K SarmaAbstract:: In this study, pox-like outbreaks in goat population was investigated that occurred in a high altitude goat farm located in Mizoram, a hilly state of North eastern India. The outbreak initially involved the serows, an wild animal belonging to the family Bovidae, subfamily Caprinae and genus Capricornis, the state animal of Mizoram. Later, the disease affected the domestic goat population. The disease was diagnosed on the basis of gross lesions and PCR amplification of partial P32 gene of capripox virus. The virus was isolated in vero cells. The full length P32 gene was sequenced and phylogenetic tree was constructed. It was revealed that the capripox virus isolated from the outbreak was closely related to the Chinese strain of Goatpox virus at both amino acid and nucleotide level. To the authors' knowledge, this is the first report on isolation and characterization of capripoxvirus from north eastern region of India.
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Expression and evaluation of recombinant P32 protein based ELISA for sero-diagnostic potential of capripox in sheep and goats.
Molecular and cellular probes, 2017Co-Authors: Gnanavel Venkatesan, Aparna Madhavan, Amit Kumar, Sargam Arya, M. Dashprakash, M. Sankar, Mahesh Kumar Teli, Muthannan Andavar Ramakrisnan, Awadh Bihari PandeyAbstract:The study is aimed to develop and evaluate a recombinant P32 protein based ELISA for sero-monitoring and sero-surveillance using known and random/suspected serum samples for capripox infections from sheep and goats. Truncated P32 gene of Goatpox virus (with an ORF of 750 bp) was expressed in E. coli BL-21 CodonPlus (DE3)-RIPL cells using pET32a vector and characterized by SDS-PAGE analysis and confirmed by western blotting as 48 kDa polyhistidine-tagged fusion protein. The protein was purified under denaturing conditions using 8M urea and characterized by SDS-PAGE and immunoblotting. The purified protein was used for optimizing ELISA in a chequerboard titration method using anti-GTPV serum as known positive. The optimized conditions were found to be 300 ng of protein/well, 1:10 dilution of antibody, 1:10000 dilution of rabbit anti-goat/sheep conjugate with 3% skim milk powder and 2% gelatin in phosphate buffer saline containing tween-20 as blocking buffer. The expressed protein was specific only for Goatpox virus and sheeppox virus but did not react with related viruses of sheep and goats namely orf virus, peste de petits ruminants virus, bluetongue virus and foot and mouth disease virus. The optimized ELISA was evaluated using pre-vaccinated, post-vaccinated and also post-challenge sera. The assay was found to have a diagnostic specificity of 100/98.7% and sensitivity of 97.1/98.1% when compared to whole virus antigen based ELISA/SNT by receiver operating characteristic (ROC) analysis. The optimized ELISA is able to determine the progression of antibody response against GTPV and SPPV following vaccination and challenge in sheep and goats. The rP32 protein based ELISA was evaluated using random field serum samples (n = 1008) suspected for sheeppox and Goatpox and it has shown positivity rate as 24.4%. The rP32 protein based ELISA was found to be specific and sensitive for sero-evaluation of sheeppox virus and Goatpox virus following vaccination and infection in sheep and goats.
Amel Omani - One of the best experts on this subject based on the ideXlab platform.
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An HRM assay to differentiate sheeppox virus vaccine strains from sheeppox virus field isolates and other capripoxvirus species
Scientific Reports, 2019Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Francisco J. Berguido, Amel OmaniAbstract:Sheep poxvirus (SPPV), goat poxvirus (GTPV) and lumpy skin disease virus (LSDV) affect small ruminants and cattle causing sheeppox (SPP), Goatpox (GTP) and lumpy skin disease (LSD) respectively. In endemic areas, vaccination with live attenuated vaccines derived from SPPV, GTPV or LSDV provides protection from SPP and GTP. As live poxviruses may cause adverse reactions in vaccinated animals, it is imperative to develop new diagnostic tools for the differentiation of SPPV field strains from attenuated vaccine strains. Within the capripoxvirus (CaPV) homolog of the variola virus B22R gene, we identified a unique region in SPPV vaccines with two deletions of 21 and 27 nucleotides and developed a High-Resolution Melting (HRM)-based assay. The HRM assay produces four distinct melting peaks, enabling the differentiation between SPPV vaccines, SPPV field isolates, GTPV and LSDV. This HRM assay is sensitive, specific, and provides a cost-effective means for the detection and classification of CaPVs and the differentiation of SPPV vaccines from SPPV field isolates.
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariame DiopAbstract:Background Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants’ production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains.
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology Journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariane DiopAbstract:Background: Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants' production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains. Results: A unique 84 base pair nucleotide deletion located between the DNA ligase gene and the VARV B22R homologue gene was found only in SPPV vaccines derived from the Romanian and Yugoslavian RM/65 strains and absent in SPPV field isolates originated from various geographical locations of Asia and Africa. In addition, we developed and evaluated a conventional PCR assay, exploiting the targeted intergenic region to differentiate SPPV vaccine virus from field isolates. The assay produced an amplicon size of 218 bp for the vaccine strains, while the SPPV field isolates resulted in a 302 bp PCR fragment. The assay showed good sensitivity and specificity, and the results were in full agreement with the sequencing data of the PCR amplicons. Conclusion: The developed assay is an improvement of currently existing diagnostic tools and, when combined with a capripox virus species-specific assay, will enhance SPP and GTP diagnosis and surveillance and facilitate epidemiological investigations in countries using live attenuated SPP vaccines. In addition, for laboratories with limited resources, the assay provides a simple and cost-effective alternative for sequencing.
Tesfaye Rufael Chibssa - One of the best experts on this subject based on the ideXlab platform.
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An HRM assay to differentiate sheeppox virus vaccine strains from sheeppox virus field isolates and other capripoxvirus species
Scientific Reports, 2019Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Francisco J. Berguido, Amel OmaniAbstract:Sheep poxvirus (SPPV), goat poxvirus (GTPV) and lumpy skin disease virus (LSDV) affect small ruminants and cattle causing sheeppox (SPP), Goatpox (GTP) and lumpy skin disease (LSD) respectively. In endemic areas, vaccination with live attenuated vaccines derived from SPPV, GTPV or LSDV provides protection from SPP and GTP. As live poxviruses may cause adverse reactions in vaccinated animals, it is imperative to develop new diagnostic tools for the differentiation of SPPV field strains from attenuated vaccine strains. Within the capripoxvirus (CaPV) homolog of the variola virus B22R gene, we identified a unique region in SPPV vaccines with two deletions of 21 and 27 nucleotides and developed a High-Resolution Melting (HRM)-based assay. The HRM assay produces four distinct melting peaks, enabling the differentiation between SPPV vaccines, SPPV field isolates, GTPV and LSDV. This HRM assay is sensitive, specific, and provides a cost-effective means for the detection and classification of CaPVs and the differentiation of SPPV vaccines from SPPV field isolates.
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariame DiopAbstract:Background Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants’ production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains.
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A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains
Virology Journal, 2018Co-Authors: Tesfaye Rufael Chibssa, Angelika Loitsch, Reingard Grabherr, Eeva S. M. Tuppurainen, Tirumala Bharani Kumar Settypalli, Nick Nwankpa, Karim Tounkara, Hafsa Madani, Amel Omani, Mariane DiopAbstract:Background: Sheeppox (SPP) and Goatpox (GTP) caused by sheeppox virus (SPPV) and Goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants' production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains. Results: A unique 84 base pair nucleotide deletion located between the DNA ligase gene and the VARV B22R homologue gene was found only in SPPV vaccines derived from the Romanian and Yugoslavian RM/65 strains and absent in SPPV field isolates originated from various geographical locations of Asia and Africa. In addition, we developed and evaluated a conventional PCR assay, exploiting the targeted intergenic region to differentiate SPPV vaccine virus from field isolates. The assay produced an amplicon size of 218 bp for the vaccine strains, while the SPPV field isolates resulted in a 302 bp PCR fragment. The assay showed good sensitivity and specificity, and the results were in full agreement with the sequencing data of the PCR amplicons. Conclusion: The developed assay is an improvement of currently existing diagnostic tools and, when combined with a capripox virus species-specific assay, will enhance SPP and GTP diagnosis and surveillance and facilitate epidemiological investigations in countries using live attenuated SPP vaccines. In addition, for laboratories with limited resources, the assay provides a simple and cost-effective alternative for sequencing.