Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Preparation of recombinant African horse sickness virus VP7 antigen via a simple method and validation of a VP7-based indirect ELISA for the detection of group-specific IgG antibodies in horse sera.
Abstract: This paper describes the production and purification of a group-specific recombinant protein VP7 of African horse sickness virus serotype 3 (AHSV-3) and validation of an I-ELISA for the detection of IgG-antibodies to VP7 in horse sera. Baculovirus-expressed VP7 crystals were purified from infected insect cells. Analytical accuracy of the I-ELISA was examined using sera (n = 38) from an experimentally infected horse, from foals born to vaccinated mares, from guinea-pigs immunized with nine serotypes of AHSV, and from sera of animals infected with other orbiviruses. Compared to traditional serological assays, the I-ELISA was more sensitive in detection of the earliest immunological response in an infected horse and declining levels of maternal immunity in foals. Antibodies to all nine serotypes of AHSV could be detected. Cross-reactivity to related orbiviruses was not observed. Diagnostic accuracy of the I-ELISA was assessed by testing sera from vaccinated horses (n = 358) residing in AHS-enzootic areas and from unvaccinated horses (n = 481) residing in an AHS-free area. Sera were categorised as positive or negative for antibodies to AHSV using virus neutralisation tests. The TG-ROC analysis was used for the selection of the cut-off value. At a cut-off of 11.9 of the high positive control serum (percentage positivity), the I-ELISA specificity was 100%, sensitivity 99.4%, and the Jouden index was 0.99.
Publication Date: 2005-01-18 PubMed ID: 15737417DOI: 10.1016/j.jviromet.2004.12.002Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Validation Study
- African Horse Sickness
- Antibodies
- Antigen
- Diagnosis
- Diagnostic Technique
- Disease Diagnosis
- Disease Surveillance
- Enzyme-Linked Immunosorbent Assay (ELISA)
- Equine Diseases
- Equine Health
- Horses
- Immunoglobulin G
- Immunology
- In Vivo
- Infectious Disease
- Serodiagnosis
- Serological Surveys
- Seroprevalence
- Serotypes
- Veterinary Medicine
- Virus
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research focuses on creating a specific protein, known as VP7, for African horse sickness virus and confirming the efficiency of an enzyme-linked immunosorbent assay (ELISA) in detecting antibodies against this protein in horse blood samples. The method presented is highlighted for its increased sensitivity in detecting the virus.
Producing the VP7 Antigen
- The researchers used Baculovirus, a type of virus that specifically infects insects, to express the VP7 protein from the African horse sickness virus (AHSV).
- The protein was then purified from the infected insect cells, to provide a pure sample of the VP7 antigen for use in their tests.
Testing the I-ELISA
- Indirect ELISA (I-ELISA) was then used to detect the presence of IgG-antibodies against the VP7 protein in horse blood samples.
- The test was applied to a range of samples, including blood from a horse infected with AHSV, foals born to vaccinated mares, guinea-pigs immunized with all nine serotypes of AHSV, and animals infected with other related orbiviruses.
- The I-ELISA demonstrated high accuracy in its results, showing no cross-reactivity with related orbiviruses and successfully identifying antibodies of all nine serotypes of AHSV.
Evaluating the Sensitivity and Specificity
- The true effectiveness of the I-ELISA was assessed by its ability to differentiate between vaccinated horses in areas affected by AHSV and unvaccinated horses in an AHS-free zone.
- Traditional virus neutralisation tests were used to categorize the blood samples as either positive or negative for antibodies against AHSV.
- The statistical measure, TG-ROC, was used to determine the most effective cut-off value for the test. The researchers chose a cut-off of 11.9% of the high positive control serum.
- At this cut-off value, the I-ELISA showed a sensitivity of 99.4% and specificity of 100%. The Jouden index was 0.99, indicating great accuracy in the test’s results.
Conclusion
- The I-ELISA provided a sensitive, accurate, and reliable method for detecting antibodies against AHSV in horses.
- This could prove beneficial in managing AHSV infections, particularly in providing early detection and monitoring of the antibody levels in infected and recently vaccinated horses.
Cite This Article
APA
Maree S, Paweska JT.
(2005).
Preparation of recombinant African horse sickness virus VP7 antigen via a simple method and validation of a VP7-based indirect ELISA for the detection of group-specific IgG antibodies in horse sera.
J Virol Methods, 125(1), 55-65.
https://doi.org/10.1016/j.jviromet.2004.12.002 Publication
Researcher Affiliations
- Department of Biochemistry, Onderstepoort Veterinary Institute, P/Bag X 5, Onderstepoort, Onderstepoort 0110, South Africa. marees@arc.agric.za
MeSH Terms
- African Horse Sickness / diagnosis
- African Horse Sickness / immunology
- African Horse Sickness Virus / immunology
- Animals
- Antibodies, Viral / blood
- Antigens, Viral / immunology
- Antigens, Viral / isolation & purification
- Baculoviridae / genetics
- Cloning, Molecular
- Enzyme-Linked Immunosorbent Assay / methods
- Genetic Vectors
- Horses
- Immunity, Maternally-Acquired
- Immunoglobulin G / blood
- Neutralization Tests
- Quality Control
- Recombinant Proteins
- Reproducibility of Results
- Sensitivity and Specificity
- Viral Core Proteins / immunology
- Viral Core Proteins / isolation & purification
- Viral Vaccines / immunology
Citations
This article has been cited 13 times.- Tinarwo M, Dennis SJ, Hitzeroth II, Meyers AE, Rybicki EP, Mbewana S. Development of an African horse sickness VP6 DIVA diagnostic ELISA. Virol J 2025 Aug 12;22(1):276.
- Huang C, Wang J, Ruan Z, Wu J, Lin Y, Cao C, Yang J, Weng Q, Jin Y, Chen P, Hua Q. Real-Time Reverse Transcription Multienzyme Isothermal Rapid Amplification for Rapid Detection of African Horse Sickness Virus. Transbound Emerg Dis 2025;2025:1852368.
- Moore S, Jukes M. The History of Baculovirology in Africa. Viruses 2023 Jul 7;15(7).
- Bekker S, Huismans H, van Staden V. Generation of a Soluble African Horse Sickness Virus VP7 Protein Capable of Forming Core-like Particles. Viruses 2022 Jul 26;14(8).
- Durán-Ferrer M, Villalba R, Fernández-Pacheco P, Tena-Tomás C, Jiménez-Clavero MÁ, Bouzada JA, Ruano MJ, Fernández-Pinero J, Arias M, Castillo-Olivares J, Agüero M. Clinical, Virological and Immunological Responses after Experimental Infection with African Horse Sickness Virus Serotype 9 in Immunologically Naïve and Vaccinated Horses. Viruses 2022 Jul 15;14(7).
- Dennis SJ, Meyers AE, Hitzeroth II, Rybicki EP. African Horse Sickness: A Review of Current Understanding and Vaccine Development. Viruses 2019 Sep 11;11(9).
- Durán-Ferrer M, Agüero M, Zientara S, Beck C, Lecollinet S, Sailleau C, Smith S, Potgieter C, Rueda P, Sastre P, Monaco F, Villalba R, Tena-Tomás C, Batten C, Frost L, Flannery J, Gubbins S, Lubisi BA, Sánchez-Vizcaíno JM, Emery M, Sturgill T, Ostlund E, Castillo-Olivares J. Assessment of reproducibility of a VP7 Blocking ELISA diagnostic test for African horse sickness. Transbound Emerg Dis 2019 Jan;66(1):83-90.
- Karamalla ST, Gubran AI, Adam IA, Abdalla TM, Sinada RO, Haroun EM, Aradaib IE. Sero-epidemioloical survey on African horse sickness virus among horses in Khartoum State, Central Sudan. BMC Vet Res 2018 Aug 1;14(1):230.
- Mathebula EM, Faber FE, Van Wyngaardt W, Van Schalkwyk A, Pretorius A, Fehrsen J. B-cell epitopes of African horse sickness virus serotype 4 recognised by immune horse sera. Onderstepoort J Vet Res 2017 Feb 24;84(1):e1-e12.
- Fowler VL, Howson ELA, Flannery J, Romito M, Lubisi A, Agüero M, Mertens P, Batten CA, Warren HR, Castillo-Olivares J. Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Assay for the Rapid Detection of African Horse Sickness Virus. Transbound Emerg Dis 2017 Oct;64(5):1579-1588.
- Liu T, Liu JF, Yu H, Si GJ, Hu J, Li J. Production of a fragment of glycoprotein G of herpes simplex virus type 2 and evaluation of its diagnostic potential. Singapore Med J 2015 Jun;56(6):346-52.
- Kumar M, Nandi S, Chidri S. Development of a polyclonal antibody-based AC-ELISA and its comparison with PCR for diagnosis of canine parvovirus infection. Virol Sin 2010 Oct;25(5):352-60.
- Chiam R, Sharp E, Maan S, Rao S, Mertens P, Blacklaws B, Davis-Poynter N, Wood J, Castillo-Olivares J. Induction of antibody responses to African horse sickness virus (AHSV) in ponies after vaccination with recombinant modified vaccinia Ankara (MVA). PLoS One 2009 Jun 22;4(6):e5997.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
