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Hu Z, Lai R, Tian X, Guan R, Li X. A duplex fluorescent quantitative PCR assay to distinguish the genotype I, II and I/II recombinant strains of African swine fever virus in China. Front Vet Sci 2024; 11:1422757. [PMID: 38895720 PMCID: PMC11183790 DOI: 10.3389/fvets.2024.1422757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
African swine fever (ASF) is a severe, hemorrhagic, and highly contagious disease caused by the African swine fever virus (ASFV) in both domestic pigs and wild boars. In China, ASFV has been present for over six years, with three genotypes of strains prevalent in field conditions: genotype I, genotype II, and genotype I/II recombinant strains. In order to differentiate among these three ASFV genotypes, a duplex fluorescent quantitative PCR method was established using specific probes and primers designed based on viral genes MGF_110-1L and O61R from ASFV strains reported in the GenBank database. Following optimization of reaction conditions, a duplex fluorescent quantitative PCR method was successfully developed. This method demonstrated no cross-reactivity with porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), classic swine fever virus (CSFV), porcine pseudorabies virus (PRV), porcine circovirus 2 (PCV2), porcine circovirus 3 (PCV3), highlighting its specificity. Sensitivity analysis revealed that the limits of detection (LODs) of this method were 2.95 × 10-1 copies/μL for the MGF_110-1L gene and 2.95 × 100 copies/μL for the O61R gene. The inter- and intra-group coefficients of variation were both <1%, indicating high reproducibility. In summary, the establishment of this duplex fluorescent quantitative PCR method not only addresses the identification of the ASFV recombinant strains but also allows for simultaneous identification of the three epidemic genotype strains.
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Affiliation(s)
- Zhiqiang Hu
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- College of Animal Science, Xichang University, Xichang, China
| | - Ranran Lai
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
| | - Xiaogang Tian
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
| | - Ran Guan
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- College of Animal Science, Xichang University, Xichang, China
| | - Xiaowen Li
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- China Agriculture Research System-Yangling Comprehensive Test Station, Yangling Besun Agricultural Industry Group Corporation Co., Ltd., Xianyang, China
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Wang Z, Wang Y, Zhang Y, Qin G, Sun W, Wang A, Wang Y, Zhang G, Zhao J. On-site detection and differentiation of African swine fever virus variants using an orthogonal CRISPR-Cas12b/Cas13a-based assay. iScience 2024; 27:109050. [PMID: 38571763 PMCID: PMC10987800 DOI: 10.1016/j.isci.2024.109050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/14/2023] [Accepted: 01/23/2024] [Indexed: 04/05/2024] Open
Abstract
The African swine fever virus (ASFV) and its variants have induced substantial economic losses in China, prompting a critical need for efficient detection methods. Several PCR-based methods have been developed to discriminate between wild-type ASFV and gene-deleted variants. However, the requirement for sophisticated equipment and skilled operators limits their use in field settings. Here, we developed a CRISPR-Cas12b/Cas13a-based detection assay that can identify ASFV variants with minimal equipment requirements and a short turnaround time. The assay utilizes the distinct DNA/RNA collateral cleavage preferences of Cas12b/Cas13a to detect two amplified targets from multiplex recombinase polymerase amplification (RPA) in a single tube, and the results can be visualized through fluorescent or lateral-flow readouts. When tested with clinical samples in field settings, our assay successfully detected all ASFV-positive samples in less than 60 min. This assay provides a rapid on-site surveillance tool for detecting ASFV and its emerging variants.
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Affiliation(s)
- Zhe Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Longhu Laboratory, Zhengzhou 450046, China
- Henan Key Laboratory of Immunobiology, Zhengzhou 450001, China
| | - Yu Wang
- Key Laboratory of Organ Regeneration and Reconstruction, Institute of Zoology, Chinese Academy of Science, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Zhang
- Key Laboratory of Organ Regeneration and Reconstruction, Institute of Zoology, Chinese Academy of Science, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Guosong Qin
- Key Laboratory of Organ Regeneration and Reconstruction, Institute of Zoology, Chinese Academy of Science, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenbo Sun
- Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Longhu Laboratory, Zhengzhou 450046, China
- Henan Key Laboratory of Immunobiology, Zhengzhou 450001, China
| | - Yanfang Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Longhu Laboratory, Zhengzhou 450046, China
- Henan Key Laboratory of Immunobiology, Zhengzhou 450001, China
- School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China
| | - Jianguo Zhao
- Key Laboratory of Organ Regeneration and Reconstruction, Institute of Zoology, Chinese Academy of Science, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
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Penrith ML, van Emmenes J, Hakizimana JN, Heath L, Kabuuka T, Misinzo G, Odoom T, Wade A, Zerbo HL, Luka PD. African Swine Fever Diagnosis in Africa: Challenges and Opportunities. Pathogens 2024; 13:296. [PMID: 38668251 PMCID: PMC11054189 DOI: 10.3390/pathogens13040296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/18/2024] [Accepted: 03/29/2024] [Indexed: 04/29/2024] Open
Abstract
The global spread of African swine fever (ASF) in recent decades has led to the need for technological advances in sampling and diagnostic techniques. The impetus for these has been the need to enable sampling by lay persons and to obtain at least a preliminary diagnosis in the field for early control measures to be put in place before final laboratory confirmation. In rural Africa, rapid diagnosis is hampered by challenges that include lack of infrastructure as well as human and financial resources. Lack of animal health personnel, access to affordable means to transport field samples to a laboratory, and lack of laboratories with the capacity to make the diagnosis result in severe under-reporting of ASF, especially in endemic areas. This review summarizes the challenges identified in gap analyses relevant to low- and middle-income countries, with a focus on Africa, and explore the opportunities provided by recent research to improve field diagnosis and quality of diagnostic samples used. Sampling techniques include invasive sampling techniques requiring trained personnel and non-invasive sampling requiring minimal training, sampling of decomposed carcass material, and preservation of samples in situations where cold chain maintenance cannot be guaranteed. Availability and efficacy of point-of-care (POC) tests for ASF has improved considerably in recent years and their application, as well as advantages and limitations, are discussed. The adequacy of existing laboratory diagnostic capacity is evaluated and opportunities for networking amongst reference and other laboratories offering diagnostic services are discussed. Maintaining laboratory diagnostic efficiency in the absence of samples during periods of quiescence is another issue that requires attention, and the role of improved laboratory networking is emphasized. Early diagnosis of ASF is key to managing the disease spread. Therefore, the establishment of the Africa Chapter of the Global African Swine Fever Research Alliance (GARA) increases opportunities for collaboration and networking among the veterinary diagnostic laboratories in the region.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa
| | - Juanita van Emmenes
- Transboundary Animal Diseases, Onderstepoort Veterinary Institute, Agricultural Research Council, Pretoria 0110, South Africa; (J.v.E.); (L.H.)
| | - Jean N. Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania; (J.N.H.); (G.M.)
| | - Livio Heath
- Transboundary Animal Diseases, Onderstepoort Veterinary Institute, Agricultural Research Council, Pretoria 0110, South Africa; (J.v.E.); (L.H.)
| | - Tonny Kabuuka
- National Livestock Resources Research Institute, National Agricultural Research Organization, Entebbe P.O. Box 295, Uganda;
| | - Gerald Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania; (J.N.H.); (G.M.)
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro P.O. Box 3019, Tanzania
| | - Theophilus Odoom
- Veterinary Services Directorate, Accra Veterinary Laboratory, Accra P.O. Box M161, Ghana;
| | - Abel Wade
- National Veterinary Laboratory (LANAVET), Garoua P.O. Box 503, Cameroon;
| | - Habibata L. Zerbo
- Ministry of Agriculture, Animal and Fisheries Resources, Ouagadougou 03 BP 907, Burkina Faso;
| | - Pam D. Luka
- Biotechnology Centre, National Veterinary Research Institute, PMB 1, Vom 930103, Nigeria
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Shi K, Qian X, Shi Y, Wei H, Pan Y, Long F, Zhou Q, Mo S, Hu L, Li Z. A triplex crystal digital PCR for the detection of genotypes I and II African swine fever virus. Front Vet Sci 2024; 11:1351596. [PMID: 38628942 PMCID: PMC11019002 DOI: 10.3389/fvets.2024.1351596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
African swine fever (ASF) is a highly contagious and lethal viral disease that causes severe hemorrhagic fever in pigs. It keeps spreading around the world, posing a severe socioeconomic risk and endangering biodiversity and domestic food security. ASF first outbroke in China in 2018, and has spread to most provinces nationwide. Genotypes I and II ASF virus (ASFV) as the etiological pathogens have been found in China. In this study, three pairs of specific primers and probes targeting the ASFV B646L gene, F1055L gene, and E183L gene were designed to detect universal, genotype I, and genotype II strains, respectively. A triplex crystal digital PCR (cdPCR) was established on the basis of optimizing various reaction conditions. The assay demonstrated remarkably sensitive with low limits of detection (LODs) of 5.120, 4.218, 4.588 copies/reaction for B646L, F1055L, and E183L gene, respectively; excellent repeatability with 1.24-2.01% intra-assay coefficients of variation (CVs) and 1.32-2.53% inter-assay CVs; good specificity for only detection of genotypes I and II ASFV, without cross-reactivity with PCV2, PRV, SIV, PRRSV, PEDV, FMDV, and CSFV. The triplex cdPCR was used to test 1,275 clinical samples from Guangxi province of China, and the positivity rates were 5.05, 3.22, and 1.02% for genotype I, genotype II, and co-infection of genotypes I and II, respectively. These 1,275 clinical samples were also detected using a reported reference triplex real-time quantitative PCR (qPCR), and the agreements of detection results between these two methods were more than 98.98%. In conclusion, the developed triplex cdPCR could be used as a rapid, sensitive, and accurate method to detect and differentiate genotypes I and II strains of ASFV.
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Affiliation(s)
- Kaichuang Shi
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
- College of Animal Science and Technology, Guangxi University, Nanning, China
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Xinxiu Qian
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Yuwen Shi
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Haina Wei
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Yi Pan
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Qingan Zhou
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Shenglan Mo
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Liping Hu
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Zongqiang Li
- College of Animal Science and Technology, Guangxi University, Nanning, China
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Hu Z, Tian X, Lai R, Wang X, Li X. Current detection methods of African swine fever virus. Front Vet Sci 2023; 10:1289676. [PMID: 38144466 PMCID: PMC10739333 DOI: 10.3389/fvets.2023.1289676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/24/2023] [Indexed: 12/26/2023] Open
Abstract
African swine fever (ASF), caused by the African swine fever virus (ASFV), is a highly contagious and notifiable animal disease in domestic pigs and wild boars, as designated by the World Organization for Animal Health (WOAH). The effective diagnosis of ASF holds great importance in promptly controlling its spread due to its increasing prevalence and the continuous emergence of variant strains. This paper offers a comprehensive review of the most common and up-to-date methods established for various genes/proteins associated with ASFV. The discussed methods primarily focus on the detection of viral genomes or particles, as well as the detection of ASFV associated antibodies. It is anticipated that this paper will serve as a reference for choosing appropriate diagnostic methods in diverse application scenarios, while also provide direction for the development of innovative technologies in the future.
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Affiliation(s)
- Zhiqiang Hu
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- Shandong New Hope Liuhe Co., Ltd., Qingdao, China
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd., (NHLH Academy of Swine Research), Dezhou, China
- China Agriculture Research System-Yangling Comprehensive Test Station, Xianyang, China
| | - Xiaogang Tian
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- Shandong New Hope Liuhe Co., Ltd., Qingdao, China
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd., (NHLH Academy of Swine Research), Dezhou, China
| | - Ranran Lai
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- Shandong New Hope Liuhe Co., Ltd., Qingdao, China
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd., (NHLH Academy of Swine Research), Dezhou, China
| | - Xinglong Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
| | - Xiaowen Li
- Shandong Engineering Laboratory of Pig and Poultry Healthy Breeding and Disease Diagnosis Technology, Xiajin New Hope Liuhe Agriculture and Animal Husbandry Co., Ltd., Dezhou, China
- Shandong New Hope Liuhe Co., Ltd., Qingdao, China
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd., (NHLH Academy of Swine Research), Dezhou, China
- China Agriculture Research System-Yangling Comprehensive Test Station, Xianyang, China
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Feed and Livestock and Poultry Products Quality and Safety Control, Ministry of Agriculture and Rural Affairs, New Hope Liuhe Co., Ltd., Chengdu, China
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Qian X, Hu L, Shi K, Wei H, Shi Y, Hu X, Zhou Q, Feng S, Long F, Mo S, Li Z. Development of a triplex real-time quantitative PCR for detection and differentiation of genotypes I and II African swine fever virus. Front Vet Sci 2023; 10:1278714. [PMID: 37929278 PMCID: PMC10620837 DOI: 10.3389/fvets.2023.1278714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/06/2023] [Indexed: 11/07/2023] Open
Abstract
African swine fever virus (ASFV) was first identified in 1921 and is extensively prevalent around the world nowadays, which has a significant negative impact on the swine industry. In China, genotype II ASFV was first discovered in 2018, and has spread quickly to different provinces in a very short time; genotype I ASFV was first found in 2020, and has been reported in several provinces since then. To establish an accurate method for detection and differentiation of genotypes I and II ASFV, three primers and probes were designed targeting the ASFV B646L gene for different genotypes, the F1055L gene for genotype I, and the E183L gene for genotype II, and a triplex real-time quantitative PCR (qPCR) for differential detection of genotypes I and II ASFV was developed after optimizing the reaction conditions. The assay showed high sensitivity, and the limits of detection (LOD) of the B646L, F1055L, and E183L genes were 399.647 copies/reaction, 374.409 copies/reaction, and 355.083 copies/reaction, respectively; the coefficients of variation (CVs) of the intra-assay and the inter-assay were 0.22-1.88% and 0.16-1.68%, respectively, showing that this method had good repeatability; the assay could detect only ASFV, without cross-reactivity with other swine viruses including PRRSV, PEDV, PDCoV, CSFV, PRV, and PCV2, showing excellent specificity of this method. A total of 3,519 clinical samples from Guangxi province, southern China, were tested by the developed assay, and 8.16% (287/3,519) samples were found to be positive for ASFV, of which 0.17% (6/3,519) samples were positive for genotype I, 7.19% (253/3,519) samples for genotype II, and 0.80% (28/3,519) samples for genotypes I and II. At the same time, these clinical samples were also tested by a previously reported multiplex qPCR, and the agreement between these two methods was more than 99.94%. In summary, the developed triplex qPCR provided a fast, specific and accurate method for detection and differentiation of genotypes I and II ASFV.
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Affiliation(s)
- Xinxiu Qian
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Liping Hu
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Kaichuang Shi
- College of Animal Science and Technology, Guangxi University, Nanning, China
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Haina Wei
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Yuwen Shi
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Xin Hu
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Qingan Zhou
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Shenglan Mo
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Zongqiang Li
- College of Animal Science and Technology, Guangxi University, Nanning, China
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Shi K, Zhao K, Wei H, Zhou Q, Shi Y, Mo S, Long F, Hu L, Feng S, Mo M. Triplex Crystal Digital PCR for the Detection and Differentiation of the Wild-Type Strain and the MGF505-2R and I177L Gene-Deleted Strain of African Swine Fever Virus. Pathogens 2023; 12:1092. [PMID: 37764900 PMCID: PMC10534775 DOI: 10.3390/pathogens12091092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
African swine fever (ASF) is a severe and highly contagious viral disease that affects domestic pigs and wild boars, characterized by a high fever and internal bleeding. The disease is caused by African swine fever virus (ASFV), which is prevalent worldwide and has led to significant economic losses in the global pig industry. In this study, three pairs of specific primers and TaqMan probes were designed for the ASFV B646L, MGF505-2R and I177L genes. After optimizing the reaction conditions of the annealing temperature, primer concentration and probe concentration, triplex crystal digital PCR (cdPCR) and triplex real-time quantitative PCR (qPCR) were developed for the detection and differentiation of the wild-type ASFV strain and the MGF505-2R and/or I177L gene-deleted ASFV strains. The results indicate that both triplex cdPCR and triplex qPCR were highly specific, sensitive and repeatable. The assays could detect only the B646L, MGF505-2R and I177L genes, without cross-reaction with other swine viruses (i.e., PRRSV, CSFV, PCV2, PCV3, PEDV, PDCoV and PRV). The limit of detection (LOD) of triplex cdPCR was 12 copies/reaction, and the LOD of triplex qPCR was 500 copies/reaction. The intra-assay and inter-assay coefficients of variation (CVs) for repeatability and reproducibility were less than 2.7% for triplex cdPCR and less than 1.8% for triplex qPCR. A total of 1510 clinical tissue samples were tested with both methods, and the positivity rates of ASFV were 14.17% (214/1510) with triplex cdPCR and 12.98% (196/1510) with triplex qPCR, with a coincidence rate of 98.81% between the two methods. The positivity rate for the MGF505-2R gene-deleted ASFV strains was 0.33% (5/1510), and no I177L gene-deleted ASFV strain was found. The results indicate that triplex cdPCR and triplex qPCR developed in this study can provide rapid, sensitive and accurate methods for the detection and differentiation of the ASFV B646L, MGF505-2R and I177L genes.
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Affiliation(s)
- Kaichuang Shi
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China; (K.Z.); (Y.S.)
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Kang Zhao
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China; (K.Z.); (Y.S.)
| | - Haina Wei
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Qingan Zhou
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Yuwen Shi
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China; (K.Z.); (Y.S.)
| | - Shenglan Mo
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Liping Hu
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China; (H.W.); (Q.Z.); (S.M.); (F.L.); (L.H.); (S.F.)
| | - Meilan Mo
- College of Animal Science and Technology, Guangxi University, Nanning 530005, China; (K.Z.); (Y.S.)
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Zuo X, Peng G, Xia Y, Xu L, Zhao Q, Zhu Y, Wang C, Liu Y, Zhao J, Wang H, Zou X. A quadruple fluorescence quantitative PCR method for the identification of wild strains of african swine fever and gene-deficient strains. Virol J 2023; 20:150. [PMID: 37452402 PMCID: PMC10347796 DOI: 10.1186/s12985-023-02111-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Originating in Africa, African swine fever (ASF) was introduced to China in 2018. This acute and highly virulent infectious disease affects domestic pigs. The World Organization for Animal Health has listed it as a statutory reportable disease, and China has listed it as a category A infectious disease. METHODS Primers and probes were designed for four ASFV genes (B646L, EP402R, MGF505-3R, and A137R). The primers/probes were highly conserved compared with the gene sequences of 21 ASFV strains. RESULTS After optimization, the calibration curve showed good linearity (R2 > 0.99), the minimum concentration of positive plasmids that could be detected was 50 copies/µL, and the minimum viral load detection limit was 102 HAD50/mL. Furthermore, quadruple quantitative polymerase chain reaction (qPCR) with nucleic acids from three porcine-derived DNA viruses and cDNAs from eight RNA viruses did not show amplification curves, indicating that the method was specific. In addition, 1 × 106, 1 × 105, and 1 × 104 copies/µL of mixed plasmids were used for the quadruple qPCR; the coefficient of variation for triplicate determination between groups was < 2%, indicating the method was reproducible. CONCLUSIONS The results obtained by testing clinical samples containing detectable EP402R, MGF505-3R, and A137R strains with different combinations of gene deletions were as expected. Therefore, the established quadruple qPCR method was validated for the molecular diagnosis of ASF using gene-deleted ASFV strains.
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Affiliation(s)
- Xuezhi Zuo
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China
| | - Guorui Peng
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Yingju Xia
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Lu Xu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Qizu Zhao
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Yuanyuan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Cheng Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China
| | - Yebing Liu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Junjie Zhao
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Haidong Wang
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China.
| | - Xingqi Zou
- China/WOAH Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing, China.
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Li Y, Niu JW, Zhou X, Chu PP, Zhang KL, Gou HC, Yang DX, Zhang JF, Li CL, Liao M, Zhai SL. Development of a multiplex qRT-PCR assay for the detection of porcine epidemic diarrhea virus, porcine transmissible gastroenteritis virus and porcine Deltacoronavirus. Front Vet Sci 2023; 10:1158585. [PMID: 37008344 PMCID: PMC10060962 DOI: 10.3389/fvets.2023.1158585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
Currently, porcine coronaviruses are prevalent in pigs, and due to the outbreak of COVID-19, porcine coronaviruses have become a research hotspot. porcine epidemic diarrhea virus (PEDV), Transmissible Gastroenteritis Virus (TGEV), and Porcine Deltacoronavirus (PDCoV) mentioned in this study mainly cause diarrhea in pigs. These viruses cause significant economic losses and pose a potential public health threat. In this study, specific primers and probes were designed according to the M gene of PEDV, the S gene of TGEV, and the M gene of PDCoV, respectively, and TaqMan probe-based multiplex real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was developed for the simultaneous detection of PEDV, TGEV, and PDCoV. This method has high sensitivity and specificity, and the detection limit of each virus can reach 2.95 × 100 copies/μl. An assay of 160 clinical samples from pigs with diarrhea showed that the positive rates of PEDV, TGEV, and PDCoV were 38.13, 1.88, and 5.00%; the coinfection rates of PEDV+TGEV, PEDV+PDCoV, TGEV+PDCoV, PEDV+TGEV+PDCoV were 1.25, 1.25, 0, 0.63%, respectively. The positive coincidence rates of the multiplex qRT-PCR and single-reaction qRT-PCR were 100%. This method is of great significance for clinical monitoring of the porcine enteric diarrhea virus and helps reduce the loss of the breeding industry and control the spread of the disease.
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Affiliation(s)
- Yan Li
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Jia-Wei Niu
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Xia Zhou
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Pin-Pin Chu
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Kun-Li Zhang
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Hong-Chao Gou
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Dong-Xia Yang
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Jian-Feng Zhang
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Chun-Ling Li
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
| | - Ming Liao
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
- Maoming Branch Center of Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology, Maoming, China
| | - Shao-Lun Zhai
- Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Institute of Animal Health Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Guangzhou, Guangdong, China
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Zhou J, Ni Y, Wang D, Fan B, Zhu X, Zhou J, Hu Y, Li L, Li B. Development of a Competitive Enzyme-Linked Immunosorbent Assay Targeting the-p30 Protein for Detection of Antibodies against African Swine Fever Virus. Viruses 2023; 15:154. [PMID: 36680193 PMCID: PMC9861063 DOI: 10.3390/v15010154] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 12/31/2022] [Accepted: 12/31/2022] [Indexed: 01/05/2023] Open
Abstract
African swine fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs of all breeds and ages, caused by African swine fever virus (ASFV). Due to the absence of a safe and efficacious vaccine, accurate laboratory diagnosis is critical for the control of ASF prevention. The p30 protein is immunogenic and stimulates a high level of antibody response to ASFV infection. We developed a panel of 4 monoclonal antibodies (mAbs) against p30 protein, and mAb-2B4 showed the highest percent of inhibition (PI) of 70% in the solid phase blocking ELISA (bELISA). Epitope mapping revealed the mAb-2B4 recognized the epitope of aa 12-18 of p30, which is conserved among various ASFV genotypes. Subsequently, a competitive enzyme-linked immunosorbent assay (cELISA) was established using HRP-labeled mAb-2B4. The cutoff for discrimination between 98 negative sera and 40 positive sera against ASFV was determined by plotting a receiver operating characteristic (ROC) curve. It yielded the area under the curve (AUC) of 0.998, and a diagnostic specificity of 97.96% and a sensitivity of 97.5% were achieved when the cutoff value was determined at 37.1%. Furthermore, the results showed an excellent repeatability of the established cELISA and no cross-reaction to antisera against six other pig pathogens. Additionally, the cELISA detected a titer of 1:256 in the positive standard serum. Overall, mAb-2B4 showed a conserved epitope and high ability to be inhibited by positive sera in ASFV antibody detection. The cELISA based on HRP-labeled mAb-2B4 offers an alternative to other assays for a broader diagnostic coverage of ASFV infection.
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Affiliation(s)
- Junming Zhou
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Yanxiu Ni
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Dandan Wang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Baochao Fan
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Xuejiao Zhu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Jinzhu Zhou
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Yiyi Hu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Li Li
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
| | - Bin Li
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing 210014, China
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China
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