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Mai TN, Sekiguchi S, Huynh TML, Cao TBP, Le VP, Dong VH, Vu VA, Wiratsudakul A. Dynamic Models of Within-Herd Transmission and Recommendation for Vaccination Coverage Requirement in the Case of African Swine Fever in Vietnam. Vet Sci 2022; 9:vetsci9060292. [PMID: 35737344 PMCID: PMC9228824 DOI: 10.3390/vetsci9060292] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/05/2022] [Accepted: 06/12/2022] [Indexed: 01/09/2023] Open
Abstract
African swine fever (ASF) is a highly contagious disease that is caused by the ASF virus (ASFV) with a high fatality rate in domestic pigs resulting in a high socio-economic impact. The pig business in Vietnam was recently affected by ASF for the first time. This study thus aimed to develop a disease dynamic model to explain how ASFV spreads in Vietnamese pig populations and suggest a protective vaccine coverage level required to prevent future outbreaks. The outbreak data were collected from ten private small-scale farms within the first wave of ASF outbreaks in Vietnam. Three methods were used to estimate the basic reproduction number (R0), including the exponential growth method, maximum likelihood method, and attack rate method. The average R0 values were estimated at 1.49 (95%CI: 1.05–2.21), 1.58 (95%CI: 0.92–2.56), and 1.46 (95%CI: 1.38–1.57), respectively. Based on the worst-case scenario, all pigs in a herd would be infected and removed within 50 days. We suggest vaccinating at least 80% of pigs on each farm once a commercially approved ASF vaccine is available. However, an improvement in biosecurity levels in small-scale farms is still greatly encouraged to prevent the introduction of the virus.
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Affiliation(s)
- Thi Ngan Mai
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam; (T.N.M.); (T.M.L.H.); (T.B.P.C.); (V.P.L.); (V.H.D.)
| | - Satoshi Sekiguchi
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan;
- Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Thi My Le Huynh
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam; (T.N.M.); (T.M.L.H.); (T.B.P.C.); (V.P.L.); (V.H.D.)
| | - Thi Bich Phuong Cao
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam; (T.N.M.); (T.M.L.H.); (T.B.P.C.); (V.P.L.); (V.H.D.)
| | - Van Phan Le
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam; (T.N.M.); (T.M.L.H.); (T.B.P.C.); (V.P.L.); (V.H.D.)
| | - Van Hieu Dong
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam; (T.N.M.); (T.M.L.H.); (T.B.P.C.); (V.P.L.); (V.H.D.)
| | - Viet Anh Vu
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi 100000, Vietnam;
| | - Anuwat Wiratsudakul
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom 73170, Thailand
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom 73170, Thailand
- Correspondence: ; Tel.: +662-441-5242
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Canter JA, Aponte T, Ramirez-Medina E, Pruitt S, Gladue DP, Borca MV, Zhu JJ. Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC. Viruses 2022; 14:v14061249. [PMID: 35746720 PMCID: PMC9229155 DOI: 10.3390/v14061249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 12/28/2022] Open
Abstract
African swine fever virus (ASFV) causes hemorrhagic fever with mortality rates of up to 100% in domestic pigs. Currently, there are no commercial vaccines for the disease. Only some live-attenuated viruses have been able to protect pigs from ASFV infection. The immune mechanisms involved in the protection are unclear. Immune sera can neutralize ASFV but incompletely. The mechanisms involved are not fully understood. Currently, there is no standardized protocol for ASFV neutralization assays. In this study, a flow cytometry-based ASFV neutralization assay was developed and tested in pig adherent PBMC using a virulent ASFV containing a fluorescent protein gene as a substrate for neutralization. As with previous studies, the percentage of infected macrophages was approximately five time higher than that of infected monocytes, and nearly all infected cells displayed no staining with anti-CD16 antibodies. Sera from naïve pigs and pigs immunized with a live-attenuated ASFV and fully protected against parental virus were used in the assay. The sera displayed incomplete neutralization with MOI-dependent neutralizing efficacies. Extracellular, but not intracellular, virions suspended in naïve serum were more infectious than those in the culture medium, as reported for some enveloped viruses, suggesting a novel mechanism of ASFV infection in macrophages. Both the intracellular and extracellular virions could not be completely neutralized.
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Affiliation(s)
- Jessica A. Canter
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Plum Island Animal Disease Center, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Theresa Aponte
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Plum Island Animal Disease Center, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Elizabeth Ramirez-Medina
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
| | - Sarah Pruitt
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
| | - Douglas P. Gladue
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
| | - Manuel V. Borca
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
| | - James J. Zhu
- Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USA; (J.A.C.); (T.A.); (E.R.-M.); (S.P.)
- Correspondence: (D.P.G.); (M.V.B.); (J.J.Z.); Tel.: +1-631-323-3131 (D.P.G.); +1-631-323-3035 (M.V.B.); +1-631-323-3186 (J.J.Z.)
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53
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Gladue DP, Borca MV. Recombinant ASF Live Attenuated Virus Strains as Experimental Vaccine Candidates. Viruses 2022; 14:v14050878. [PMID: 35632620 PMCID: PMC9146452 DOI: 10.3390/v14050878] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
African swine fever (ASF) is causing a pandemic affecting swine in a large geographical area of the Eastern Hemisphere, from Central Europe to East and Southeast Asia, and recently in the Americas, the Dominican Republic and Haiti. The etiological agent, ASF virus (ASFV), infects both domestic and wild swine and produces a variety of clinical presentations depending on the virus strain and the genetics of the pigs infected. No commercial vaccines are currently available, although experimental recombinant live attenuated vaccine candidates have been shown to be efficacious in protecting animals against disease when challenged with homologous virulent strains. This review attempts to systematically provide an overview of all the live attenuated strains that have been shown to be experimental vaccine candidates. Moreover, it aims to analyze the development of these vaccine candidates, obtained by deleting specific genes or group of genes, and their efficacy in preventing virus infection and clinical disease after being challenged with virulent isolates. This report summarizes all the experimental vaccine strains that have shown promise against the contemporary pandemic strain of African swine fever.
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Development of a p72 trimer-based colloidal gold strip for detection of antibodies against African swine fever virus. Appl Microbiol Biotechnol 2022; 106:2703-2714. [PMID: 35291024 PMCID: PMC8923092 DOI: 10.1007/s00253-022-11851-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/22/2022] [Accepted: 02/26/2022] [Indexed: 11/24/2022]
Abstract
Abstract African swine fever virus (ASFV) causes a highly contagious and often lethal swine viral disease, and leads to tremendous economic losses to the swine industry. Unfortunately, there are no vaccines and effective antiviral agents available to prevent and control ASFV outbreaks. Therefore, it is necessary to develop simple and rapid strategies to monitor ASFV-infected pigs to restrain its spread. In the current study, ASFV capsid protein p72 was expressed along with its chaperone pB602L to form trimers in human embryonic kidney 293 (HEK293) cells. The p72 trimers were subsequently labeled with colloidal gold to develop a immunochromatographic strip. The strip showed high specificity to ASFV-positive serum and no cross-reactivity to other swine virus positive sera. Importantly, the strip showed a higher sensitivity of detecting ASFV antibodies in both positive standard serum and clinical serum samples than a commercial enzyme-linked immunosorbent assay (ELISA) kit. Taken together, these results demonstrate the strip as a reliable diagnostic tool against ASFV infection, which will be appropriate for application in prevention and control of ASFV. Key points • ASFV p72 trimers were successfully generated. • A colloidal gold strip was developed based on ASFV p72 trimers. • The strip is appropriate for detecting ASFV antibodies in the field.
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Ravilov RK, Rizvanov AA, Mingaleev DN, Galeeva AG, Zakirova EY, Shuralev EA, Rutland CS, Khammadov NI, Efimova MA. Viral Vector Vaccines Against ASF: Problems and Prospectives. Front Vet Sci 2022; 9:830244. [PMID: 35359666 PMCID: PMC8963494 DOI: 10.3389/fvets.2022.830244] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/11/2022] [Indexed: 11/13/2022] Open
Abstract
African swine fever (ASF) is a highly contagious viral disease affecting pigs, with mortality rates a primary focus as they can reach up to 100%. The widespread and colossal economic losses from ASF have impacts on the development of animal husbandry practices in most countries within Africa, Asia, and Europe. Currently, a variety of approaches toward the development of vaccines against ASF are being employed. A promising new concept centered around more economical and time-consuming vaccine production is based on the use of viral vectors to deliver selected immunogens. This review discusses the results obtained from testing various viral vectors as carriers of targeted ASF virus genes. The safety and prospects of viral vectors, the possibilities around modulating cellular and humoral immune responses by choosing genes expressing immunodominant antigens, and the degree of protection in experimental animals from infection with a lethal dose of virulent ASF virus strains have been shown and discussed.
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Affiliation(s)
- Rustam Kh. Ravilov
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
| | - Albert A. Rizvanov
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
- Kazan (Volga Region) Federal University, Kazan, Russia
| | - Danil N. Mingaleev
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
| | - Antonina G. Galeeva
- Kazan (Volga Region) Federal University, Kazan, Russia
- Federal Center for Toxicological, Radiation and Biological Safety, Kazan, Russia
- *Correspondence: Antonina G. Galeeva
| | - Elena Yu. Zakirova
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
- Kazan (Volga Region) Federal University, Kazan, Russia
| | - Eduard A. Shuralev
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
- Kazan (Volga Region) Federal University, Kazan, Russia
- Kazan State Medical Academy, Kazan, Russia
| | - Catrin S. Rutland
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Nottingham, United Kingdom
| | - Nail I. Khammadov
- Federal Center for Toxicological, Radiation and Biological Safety, Kazan, Russia
| | - Marina A. Efimova
- Kazan State Academy of Veterinary Medicine named after N. E. Bauman, Kazan, Russia
- Federal Center for Toxicological, Radiation and Biological Safety, Kazan, Russia
- Kazan State Medical Academy, Kazan, Russia
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Zou T, Deng J, Li X, Zhang S, Chen L, Hao L, Zhuang J, Wang H, Zhang G, Ge S, Tian K. Development of a fluorescent probe hydrolysis-insulated isothermal PCR for rapid and sensitive on-site detection of African swine fever virus. Virol Sin 2022; 37:462-464. [PMID: 35257964 PMCID: PMC9243616 DOI: 10.1016/j.virs.2022.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/01/2022] [Indexed: 12/22/2022] Open
Abstract
A probe-based insulated isothermal PCR (iiPCR) assay was developed for rapid and onsite detection of ASFV. The developed iiPCR showed similar sensitivity and specificity with OIE recommended real-time PCR. Blood samples could be directly applied as PCR template in iiPCR without DNA extraction.
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Affiliation(s)
- Tianli Zou
- Beijing Wantai Biopharmaceutical Co., Ltd, Beijing, 102206, China
| | - Junhua Deng
- Luoyang Putai Bio-Tech Co. Ltd, Luoyang, 471003, China
| | - Xiangdong Li
- National Research Center for Veterinary Medicine, Luoyang, 471003, China
| | - Shiyin Zhang
- School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Lingyan Chen
- Luoyang Putai Bio-Tech Co. Ltd, Luoyang, 471003, China
| | - Liying Hao
- Luoyang Putai Bio-Tech Co. Ltd, Luoyang, 471003, China
| | | | - Heng Wang
- ASFV Regional Reference Laboratory in Guangzhou, South China Agricultural University, Guangzhou, 510642, China
| | - Guihong Zhang
- ASFV Regional Reference Laboratory in Guangzhou, South China Agricultural University, Guangzhou, 510642, China
| | - Shengxiang Ge
- School of Public Health, Xiamen University, Xiamen, 361102, China.
| | - Kegong Tian
- Luoyang Putai Bio-Tech Co. Ltd, Luoyang, 471003, China; National Research Center for Veterinary Medicine, Luoyang, 471003, China.
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57
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Yin D, Geng R, Lv H, Bao C, Shao H, Ye J, Qian K, Qin A. Development of Real-Time PCR Based on A137R Gene for the Detection of African Swine Fever Virus. Front Vet Sci 2021; 8:753967. [PMID: 34912874 PMCID: PMC8666952 DOI: 10.3389/fvets.2021.753967] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
African swine fever virus (ASFV) can infect domestic pigs and wild boars and causes huge economic losses in global swine industry. Therefore, early diagnosis of ASFV is important for the control and eradication of African swine fever (ASF). In this study, a SYBR Green-based real-time polymerase chain reaction (PCR) assay targeting the viral encoded A137R gene was established for the detection of ASFV infection. For the evaluation of the established real-time PCR, 34 clinical samples were assessed by both the A137R gene-based real-time PCR and OIE-recommended TaqMan PCR. The results showed that 85.29% (29/34) were detected by A137R gene-based real-time PCR, but only 79.41% (27/34) positive using OIE-recommended TaqMan PCR. Moreover, no cross-reaction with other common swine pathogens was found in the A137R gene-based real-time PCR. These results demonstrated that the established real-time PCR assay in this study showed better performance than the OIE-recommended method in detecting ASFV from clinical samples, which could be applied for control and eradication programs of ASF.
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Affiliation(s)
- Dan Yin
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Renhao Geng
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Hui Lv
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Chunhui Bao
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Hongxia Shao
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Jianqiang Ye
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Kun Qian
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
| | - Aijian Qin
- The International Joint Laboratory for Cooperation in Agriculture and Agricultural Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
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Spatiotemporally Orchestrated Interactions between Viral and Cellular Proteins Involved in the Entry of African Swine Fever Virus. Viruses 2021; 13:v13122495. [PMID: 34960765 PMCID: PMC8703583 DOI: 10.3390/v13122495] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/27/2021] [Accepted: 12/09/2021] [Indexed: 12/11/2022] Open
Abstract
African swine fever (ASF) is a highly contagious hemorrhagic disease in domestic pigs and wild boars with a mortality of up to 100%. The causative agent, African swine fever virus (ASFV), is a member of the Asfarviridae family of the nucleocytoplasmic large DNA viruses. The genome size of ASFV ranges from 170 to 194 kb, encoding more than 50 structural and 100 nonstructural proteins. ASFV virions are 260–300 nm in diameter and composed of complex multilayered structures, leading to an intricate internalization pathway to enter host cells. Currently, no commercial vaccines or antivirals are available, due to the insufficient knowledge of the viral receptor(s), the molecular events of ASFV entry into host cells, and the functions of virulence-associated genes. During the early stage of ASFV infection, the fundamental aspects of virus-host interactions, including virus internalization, intracellular transport through the endolysosomal system, and membrane fusion with endosome, are precisely regulated and orchestrated via a series of molecular events. In this review, we summarize the currently available knowledge on the pathways of ASFV entry into host cells and the functions of viral proteins involved in virus entry. Furthermore, we conclude with future perspectives and highlight areas that require further investigation. This review is expected to provide unique insights for further understanding ASFV entry and facilitate the development of vaccines and antivirals.
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Njau EP, Machuka EM, Cleaveland S, Shirima GM, Kusiluka LJ, Okoth EA, Pelle R. African Swine Fever Virus (ASFV): Biology, Genomics and Genotypes Circulating in Sub-Saharan Africa. Viruses 2021; 13:2285. [PMID: 34835091 PMCID: PMC8623397 DOI: 10.3390/v13112285] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/17/2021] [Accepted: 11/03/2021] [Indexed: 12/22/2022] Open
Abstract
African swine fever (ASF) is a highly infectious and fatal haemorrhagic disease of pigs that is caused by a complex DNA virus of the genus Asfivirus and Asfarviridae African suids family. The disease is among the most devastating pig diseases worldwide including Africa. Although the disease was first reported in the 19th century, it has continued to spread in Africa and other parts of the world. Globally, the rising demand for pork and concomitant increase in transboundary movements of pigs and pork products is likely to increase the risk of transmission and spread of ASF and pose a major challenge to the pig industry. Different genotypes of the ASF virus (ASFV) with varying virulence have been associated with different outbreaks in several countries in sub-Saharan Africa (SSA) and worldwide, and understanding genotype circulation will be important for ASF prevention and control strategies. ASFV genotypes unique to Africa have also been reported in SSA. This review briefly recounts the biology, genomics and genotyping of ASFV and provides an account of the different genotypes circulating in SSA. The review also highlights prevention, control and progress on vaccine development and identifies gaps in knowledge of ASFV genotype circulation in SSA that need to be addressed.
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Affiliation(s)
- Emma P. Njau
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3015, Tanzania
| | - Eunice M. Machuka
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
| | - Sarah Cleaveland
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Gabriel M. Shirima
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
| | - Lughano J. Kusiluka
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3015, Tanzania
- Mzumbe University, Morogoro P.O. Box 1, Tanzania
| | - Edward A. Okoth
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
| | - Roger Pelle
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
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Sun W, Zhang H, Fan W, He L, Chen T, Zhou X, Qi Y, Sun L, Hu R, Luo T, Liu W, Li J. Evaluation of Cellular Immunity with ASFV Infection by Swine Leukocyte Antigen (SLA)-Peptide Tetramers. Viruses 2021; 13:v13112264. [PMID: 34835070 PMCID: PMC8617699 DOI: 10.3390/v13112264] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/05/2021] [Accepted: 11/10/2021] [Indexed: 12/27/2022] Open
Abstract
African swine fever virus (ASFV) causes acute hemorrhagic fever in domestic pigs and wild boars, resulting in incalculable economic losses to the pig industry. As the mechanism of viral infection is not clear, protective antigens have not been discovered or identified. In this study, we determined that the p30, pp62, p72, and CD2v proteins were all involved in the T cell immune response of live pigs infected with ASFV, among which p72 and pp62 proteins were the strongest. Panoramic scanning was performed on T cell epitopes of the p72 protein, and three high-frequency positive epitopes were selected to construct a swine leukocyte antigen (SLA)-tetramer, and ASFV-specific T cells were detected. Subsequently, the specific T cell and humoral immune responses of ASFV-infected pigs and surviving pigs were compared. The results demonstrate that the specific T cellular immunity responses gradually increased during the infection and were higher than that in the surviving pigs in the late stages of infection. The same trend was observed in specific humoral immune responses, which were highest in surviving pigs. In general, our study provides key information for the exploration of ASFV-specific immune responses and the development of an ASFV vaccine.
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Affiliation(s)
- Wenqiang Sun
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
| | - He Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
| | - Wenhui Fan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
| | - Lihong He
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Teng Chen
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Xintao Zhou
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Yu Qi
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
| | - Lei Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rongliang Hu
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun 130122, China; (T.C.); (X.Z.); (Y.Q.)
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Tingrong Luo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Wenjun Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Laboratory of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Guangxi University, Nanning 530004, China;
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
| | - Jing Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (H.Z.); (W.F.); (L.H.); (L.S.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (R.H.); (T.L.); (W.L.); (J.L.)
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Tran HTT, Truong AD, Ly DV, Hoang TV, Chu NT, Nguyen HT, Dang ATK, De Vos M, Lannoo K, Bruggeman G, Dang HV. The potential anti-African swine fever virus effects of medium chain fatty acids on in vitro feed model: An evaluation study using epidemic ASFV strain circulating in Vietnam. Open Vet J 2021; 11:346-355. [PMID: 34722195 PMCID: PMC8541713 DOI: 10.5455/ovj.2021.v11.i3.3] [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: 05/11/2021] [Accepted: 06/22/2021] [Indexed: 11/03/2022] Open
Abstract
Background African swine fever (ASF) is an important disease affecting swine and has a significant economic loss in both the developed and developing world. Aim In this study, we evaluated the potential effects of medium-chain fatty acids (MCFAs) in individual and synergistic forms to prevent and/or reduce ASF virus (ASFV) infection using in vitro feed model. Methods The cytotoxicity of MCFAs on porcine alveolar macrophages cells was evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The potential effects of MCFAs, including C8 (caprylic acid), C8-C6-C10 (caprylic acid-caproic acid-capric acid; 1:1:1 ratio) and C8-C10-C12 (caprylic acid-capric acid-lauric acid; 1:1:1 ratio) against a field ASFV strain isolated in the capital Hanoi of Vietnam, were further examined by real-time PCR and haemadsorption assays in in vitro feed model. Results Our results indicated that all tested products do not induce cytotoxicity at the dose of 100 μg/ml and are suitable for further in vitro examination. These products have shown a strong antiviral effect against ASFV infectivity at doses of 0.375% and 0.5%. Interestingly, the synergistic MCFAs have shown clearly their potential activities against ASFV in which at a lower dose of 0.25%, pre-treatment with product two and three induced significant increases at the level of Cq value when compared to positive control and/or product 1 (p < 0.05). However, the viral titre was not changed after 24 hours post-inoculation when compared to positive control. Our findings suggested that all tested products, both individual and synergistic forms of MCFAs, have possessed a strong anti-ASFV effect, and this effect is dose-dependence in in vitro feed model. Additionally, synergistic effects of MCFAs are more effective against ASFV when compared to individual forms. Conclusion Together, the findings in this study indicate that MCFAs, both individual and synergistic forms, inhibit against a field ASFV strain in the feed model, which may support minimizing the risk of ASF transmission in the pig population. Further studies focusing on in vivo anti-ASFV effects of MCFAs are important to bring new insight into the mode of ASFV-reduced action by these compounds in swine feed.
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Affiliation(s)
- Ha Thi Thanh Tran
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam.,These authors contributed equally to this work
| | - Anh Duc Truong
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam.,These authors contributed equally to this work
| | - Duc Viet Ly
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
| | - Tuan Van Hoang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
| | - Nhu Thi Chu
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
| | - Huyen Thi Nguyen
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
| | - Anh Thi Kieu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
| | | | - Kobe Lannoo
- Royal Agrifirm Group, Apeldoorn, The Netherlands
| | | | - Hoang Vu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research (NIVR), Hanoi, Vietnam
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Guo Z, Zhuo Y, Li K, Niu S, Dai H. Recent advances in cell homeostasis by African swine fever virus-host interactions. Res Vet Sci 2021; 141:4-13. [PMID: 34634684 DOI: 10.1016/j.rvsc.2021.10.003] [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: 12/09/2020] [Revised: 09/07/2021] [Accepted: 10/05/2021] [Indexed: 10/20/2022]
Abstract
African swine fever (ASF) is an acute hemorrhagic disease caused by the infection of domestic swine and wild boar by the African swine fever virus (ASFV), with a mortality rate close to 90-100%. ASFV has been spreading in the world and poses a severe economic threat to the swine industry. There is no high effective vaccine commercially available or drug for this disease. However, attenuated ASFV isolates may infect pigs by chronic infection, and the infected pigs will not be lethal, which may indicate that pigs can produce protective immunity to resistant ASFV. Immunity acquisition and virus clearances are the central pillars to maintain the host normal cell activities and animal survival dependent on virus-host interactions, which has offered insights into the biology of ASFV. This review is organized around general themes including native immunity, endoplasmic reticulum stress, cell apoptosis, ubiquitination, autophagy regarding the intricate relationship between ASFV protein-host. Elucidating the multifunctional role of ASFV proteins in virus-host interactions can provide more new insights on the initial virus sensing, clearance, and cell homeostasis, and contribute to understanding viral pathogenesis and developing novel antiviral therapeutics.
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Affiliation(s)
- Zeheng Guo
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei 430070, China
| | - Yisha Zhuo
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei 430070, China
| | - Keke Li
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei 430070, China
| | - Sai Niu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei 430070, China
| | - Hanchuan Dai
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan, Hubei 430070, China.
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A QP509L/QP383R-deleted African swine fever virus is highly attenuated in swine but does not confer protection against parental virus challenge. J Virol 2021; 96:e0150021. [PMID: 34613824 PMCID: PMC8754219 DOI: 10.1128/jvi.01500-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
African swine fever (ASF), a devastating infectious disease in swine, severely threatens the global pig farming industry. Disease control has been hampered by the unavailability of vaccines. Here, we report that deletion of the QP509L and QP383R genes (ASFV-ΔQP509L/QP383R) from the highly virulent ASF virus (ASFV) CN/GS/2018 strain results in complete viral attenuation in swine. Animals inoculated with ASFV-ΔQP509L/QP383R at a 104 50% hemadsorbing dose (HAD50) remained clinically normal during the 17-day observational period. All ASFV-ΔQP509L/QP383R-infected animals had low viremia titers and developed a low-level p30-specific antibody response. However, ASFV-ΔQP509L/QP383R did not induce protection against challenge with the virulent parental ASFV CN/GS/2018 isolate. RNA-sequencing analysis revealed that innate immune-related genes (Ifnb, Traf2, Cxcl10, Isg15, Rantes, and Mx1) were significantly lower in ASFV-ΔQP509L/QP383R-infected than in ASFV-infected porcine alveolar macrophages. In addition, ASFV-ΔQP509L/QP383R-infected pigs had low levels of interferon-β (IFN-β) based on enzyme-linked immunosorbent assay (ELISA). These data suggest that deletion of ASFV QP509L/383R reduces virulence but does not induce protection against lethal ASFV challenge. IMPORTANCE African swine fever (ASF) is endemic to several parts of the word, with outbreaks of the disease devastating the swine farming industry; currently, no commercially available vaccine exists. Here, we report that deletion of the previously uncharacterized QP509L and QP383R viral genes completely attenuates virulence in the ASF virus (ASFV) CN/GS/2018 isolate. However, ASFV-ΔQP509L/QP383R-infected animals were not protected from developing an ASF infection after challenge with the virulent parental virus. ASFV-ΔQP509L/QP383R induced lower levels of innate immune-related genes and IFN-β than the parental virus. Our results increase our knowledge of developing an effective and live ASF attenuated vaccine.
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Chen XL, Wang JH, Zhao W, Shi CW, Yang KD, Niu TM, Yang GL, Cao X, Jiang YL, Wang JZ, Huang HB, Zeng Y, Wang N, Yang WT, Wang CF. Lactobacillus plantarum surface-displayed ASFV (p54) with porcine IL-21 generally stimulates protective immune responses in mice. AMB Express 2021; 11:114. [PMID: 34383171 PMCID: PMC8360262 DOI: 10.1186/s13568-021-01275-9] [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: 03/09/2021] [Accepted: 08/05/2021] [Indexed: 02/06/2023] Open
Abstract
African classical swine fever virus (ASFV) has spread seriously around the world and has dealt with a heavy blow to the pig breeding industry due to the lack of vaccines. In this study, we produced recombinant Lactobacillus plantarum (L. plantarum) expressing an ASFV p54 and porcine IL-21 (pIL-21) fusion protein and evaluated the immune effect of NC8-pSIP409-pgsA'-p54-pIL-21 in a mouse model. First, we verified that the ASFV p54 protein and p54-pIL-21 fusion protein were anchored on the surface of L. plantarum NC8 by flow cytometry, immunofluorescence and Western blotting. Then, the results were verified by flow cytometry, ELISA and MTT assays. Mouse-specific humoral immunity and mucosal and T cell-mediated immune responses were induced by recombinant L. plantarum. The results of feeding mice recombinant L. plantarum showed that the levels of serum IgG and mucosal secreted IgA (SIgA), the number of CD4 and CD8 T cells, and the expression of IFN-γ in CD4 and CD8 T cells increased significantly, and lymphocyte proliferation occurred under stimulation with the ASFV p54 protein. Our data lay a foundation for the development of oral vaccines against ASFV in the future.
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Clemmons EA, Alfson KJ, Dutton JW. Transboundary Animal Diseases, an Overview of 17 Diseases with Potential for Global Spread and Serious Consequences. Animals (Basel) 2021; 11:2039. [PMID: 34359167 PMCID: PMC8300273 DOI: 10.3390/ani11072039] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 12/21/2022] Open
Abstract
Animals provide food and other critical resources to most of the global population. As such, diseases of animals can cause dire consequences, especially disease with high rates of morbidity or mortality. Transboundary animal diseases (TADs) are highly contagious or transmissible, epidemic diseases, with the potential to spread rapidly across the globe and the potential to cause substantial socioeconomic and public health consequences. Transboundary animal diseases can threaten the global food supply, reduce the availability of non-food animal products, or cause the loss of human productivity or life. Further, TADs result in socioeconomic consequences from costs of control or preventative measures, and from trade restrictions. A greater understanding of the transmission, spread, and pathogenesis of these diseases is required. Further work is also needed to improve the efficacy and cost of both diagnostics and vaccines. This review aims to give a broad overview of 17 TADs, providing researchers and veterinarians with a current, succinct resource of salient details regarding these significant diseases. For each disease, we provide a synopsis of the disease and its status, species and geographic areas affected, a summary of in vitro or in vivo research models, and when available, information regarding prevention or treatment.
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Affiliation(s)
- Elizabeth A. Clemmons
- Southwest National Primate Research Center, Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA;
| | - Kendra J. Alfson
- Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA
| | - John W. Dutton
- Southwest National Primate Research Center, Texas Biomedical Research Institute, 8715 W. Military Drive, San Antonio, TX 78227, USA;
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African Swine Fever Virus as a Difficult Opponent in the Fight for a Vaccine-Current Data. Viruses 2021; 13:v13071212. [PMID: 34201761 PMCID: PMC8310326 DOI: 10.3390/v13071212] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/17/2021] [Accepted: 06/19/2021] [Indexed: 12/13/2022] Open
Abstract
Prevention and control of African swine fever virus (ASFV) in Europe, Asia, and Africa seem to be extremely difficult in view of the ease with which it spreads, its high resistance to environmental conditions, and the many obstacles related to the introduction of effective specific immunoprophylaxis. Biological properties of ASFV indicate that the African swine fever (ASF) pandemic will continue to develop and that only the implementation of an effective and safe vaccine will ensure a reduction in the spread of ASFV. At present, vaccines against ASF are not available. The latest approaches to the ASFV vaccine’s design concentrate on the development of either modified live vaccines by targeted gene deletion from different isolates or subunit vaccines. The construction of an effective vaccine is hindered by the complex structure of the virus, the lack of an effective continuous cell line for the isolation and propagation of ASFV, unpredictable and stain-specific phenotypes after the genetic modification of ASFV, a risk of reversion to virulence, and our current inability to differentiate infected animals from vaccinated ones. Moreover, the design of vaccines intended for wild boars and oral administration is desirable. Despite several obstacles, the design of a safe and effective vaccine against ASFV seems to be achievable.
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Development of a Blocking Enzyme-Linked Immunosorbent Assay for Detection of Antibodies against African Swine Fever Virus. Pathogens 2021; 10:pathogens10060760. [PMID: 34204199 PMCID: PMC8234086 DOI: 10.3390/pathogens10060760] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/12/2021] [Accepted: 06/13/2021] [Indexed: 11/16/2022] Open
Abstract
The incursion of African swine fever virus (ASFV) into Eurasia presents a threat to the world's swine industry. Highly sensitive and specific diagnostic assays are urgently needed for rapid detection during an outbreak, post-outbreak investigation, and disease surveillance. In this study, a highly specific and repeatable blocking ELISA (bELISA) was developed using a recombinant p30 protein as the antigen combined with biotinylated mAb against p30 as the detection antibody. Initial test validation included sera from 810 uninfected animals and 106 animals experimentally inoculated with ASFV or recombinant alphavirus/adenovirus expressing p30. Receiver operating characteristic (ROC) analysis of the data calculated an optimal percentage of inhibition (PI) cutoff value of 45.92%, giving a diagnostic sensitivity of 98.11% and diagnostic specificity of 99.42%. The coefficient of variation of an internal quality control serum was 6.81% for between runs, 6.71% for within run, and 6.14% for within plate. A time course study of infected pigs showed that bELISA was able to detect seroconversion as early as 7 days post-inoculation. Taken together, these results demonstrate that bELISA can be used as an alternative serological test for detecting ASFV infection.
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Thoughts on African Swine Fever Vaccines. Viruses 2021; 13:v13050943. [PMID: 34065425 PMCID: PMC8161283 DOI: 10.3390/v13050943] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 12/22/2022] Open
Abstract
African swine fever (ASF) is an acute viral hemorrhagic disease of domestic swine with mortality rates approaching 100%. Devastating ASF outbreaks and continuing epidemics starting in the Caucasus region and now in the Russian Federation, Europe, China, and other parts of Southeast Asia (2007 to date) highlight its significance. ASF strain Georgia-07 and its derivatives are now endemic in extensive regions of Europe and Asia and are "out of Africa" forever, a situation that poses a grave if not an existential threat to the swine industry worldwide. While our current concern is Georgia-07, other emerging ASFV strains will threaten for the indefinite future. Economic analysis indicates that an ASF outbreak in the U.S. would result in approximately $15 billion USD in losses, assuming the disease is rapidly controlled and the U.S. is able to reenter export markets within two years. ASF's potential to spread and become endemic in new regions, its rapid and efficient transmission among pigs, and the relative stability of the causative agent ASF virus (ASFV) in the environment all provide significant challenges for disease control. Effective and robust methods, including vaccines for ASF response and recovery, are needed immediately.
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Yang S, Zhang X, Cao Y, Li S, Shao J, Sun S, Guo H, Yin S. Identification of a new cell-penetrating peptide derived from the african swine fever virus CD2v protein. Drug Deliv 2021; 28:957-962. [PMID: 34006158 PMCID: PMC8143602 DOI: 10.1080/10717544.2021.1909178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The African swine fever virus (ASFV) is a huge and complex DNA virus that can lead to the acute death of pigs and cause huge losses to the global swine industry. The CD2v protein is a transmembrane protein encoded by the ASFV’s EP402R gene, which can effectively inhibit the bystander lymphocyte proliferation in response to mitogens and mediate the absorption of red blood cells to ASFV-infected cells. The CD2v protein contains repetitive amino acid sequences ([KPCPPP]3 labeled as RAAS), which is reported as a genetic marker and an epitope. However, the specific biological function of the RAAS is unknown. Here, we have found that the truncated CD2v protein with RAAS can enter Chinese hamster ovary cells, but the truncated CD2v protein without RAAS cannot enter the cells. Also, the RAAS can carry the macromolecular protein EGFP to enter various cells through multiple endocytic processes that are dependent on time, concentration, and location. Besides, the RAAS enter the cells via the macropinocytosis or the clathrin-mediated endocytosis. These results indicate that the RAAS can function as a cell-penetrating peptide that provides a new insight for ASFV research and has potential application value as a tool for drug delivery.
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Affiliation(s)
- Shunli Yang
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Xinming Zhang
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Yuying Cao
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Shuo Li
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Junjun Shao
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Shiqi Sun
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Huichen Guo
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China.,College of Animal Science, Yangtze University, Jingzhou, P. R. China
| | - Shuanghui Yin
- State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
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Application of portable real-time recombinase-aided amplification (rt-RAA) assay in the clinical diagnosis of ASFV and prospective DIVA diagnosis. Appl Microbiol Biotechnol 2021; 105:3249-3264. [PMID: 33835201 DOI: 10.1007/s00253-021-11196-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 02/08/2021] [Accepted: 02/24/2021] [Indexed: 10/21/2022]
Abstract
African swine fever, a serious infectious disease, has been found in many countries around the world over the last nearly 100 years, and causes untold damage to the economy wherever it occurs. Diagnosis is currently performed by real-time PCR, which is highly sensitive but can only be carried out in a diagnostic laboratory environment with sophisticated equipment and expertise. A sensitive, rapid diagnostic method that can be implemented in agricultural settings is thus urgently needed for the detection and control of African swine fever virus (ASFV) infection. In this study, we developed an isothermal amplification technology to achieve molecular diagnosis of ASFV in clinical samples, using recombinase-aided amplification (RAA) assay combined with a portable instrument. This assay method avoids the limitations of traditional real-time PCR and offers detection times within 20 min, enabling detection of as few as 10 copies of ASFV DNA molecules per reaction without cross-reaction with other common swine viruses. We evaluated clinical performance using 200 clinical blood samples. The coincidence rate of the detection results between rt-RAA and RT-qPCR was 96.94% positive, 100% negative, and 97.50% total. We have also developed an rt-RAA system for the detection of ASFV targeting the EP402R gene, with detection of as few as 10 copies of DNA per reaction; this offers the possibility of DIVA (differentiating infected from vaccinated animals) diagnosis, because CD2V gene-deleted ASFV could soon be approved to be the leading candidate for live attenuated vaccine in China. The rt-RAA assay is a reliable, rapid, highly sensitive method, and it offers a reasonable alternative to RT-qPCR for point-of-care detection of ASFV. KEY POINTS: • The RT-RAA assay can detect as few as 10 copies of ASFV genome per reaction within 20 min. • The rt-RAA assay system targeting different genes can achieve differentiating infected from vaccinated diagnosis.
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Liu K, Meng Y, Chai Y, Li L, Sun H, Gao GF, Tan S, Qi J. Crystal structure of the African swine fever virus core shell protein p15. BIOSAFETY AND HEALTH 2021. [DOI: 10.1016/j.bsheal.2020.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Wang A, Jiang M, Liu H, Liu Y, Zhou J, Chen Y, Ding P, Wang Y, Pang W, Qi Y, Zhang G. Development and characterization of monoclonal antibodies against the N-terminal domain of African swine fever virus structural protein, p54. Int J Biol Macromol 2021; 180:203-211. [PMID: 33737177 DOI: 10.1016/j.ijbiomac.2021.03.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/11/2021] [Accepted: 03/11/2021] [Indexed: 12/28/2022]
Abstract
African swine fever virus (ASFV), a re-emerging DNA virus, causes a highly contagious disease for domestic pigs. It is running rife worldwide and threatening the global swine industry. Protein p54 is an attractive candidate for ASFV diagnostic and vaccine design. In this work, we designed a peptide to mimic the N-terminal domain (NTD) of ASFV p54 and pretested it with sera from ASFV-infected pigs. The peptide could be well recognized by the sera, implying that the NTD of p54 contained some potential linear B cell epitopes. Then, the conjugates of the peptide with bovine serum albumin were used as the immunogen to generate monoclonal antibodies (mAbs). A total of six mAbs specific to the NTD of ASFV p54 protein were developed. Five of them well reacted with ASFV HLJ/18 strain and recognized a same linear B cell epitope 5FFQPV9. Furthermore, epitope 5FFQPV9 could be well recognized by ASFV-positive sera from natural infected pigs, suggesting that it was a natural linear B-cell epitope. Conservation analysis indicated that epitope 5FFQPV9 were highly conserved among ASFV epidemic isolates belonging to genotype I and II. Alanine-scanning mutagenesis further revealed that the residues (6F to 9V) of epitope 5FFQPV9 were the core binding sites for antibody recognition. This is the first research to characterize specific mAbs against NTD of p54 protein. These findings may help further understand the function of p54 protein and the improvement of ASFV diagnosis.
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Affiliation(s)
- Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Min Jiang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Hongliang Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yankai Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jingming Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Peiyang Ding
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yanwei Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Weisheng Pang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yanhua Qi
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China.
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High Doses of Inactivated African Swine Fever Virus Are Safe, but Do Not Confer Protection against a Virulent Challenge. Vaccines (Basel) 2021; 9:vaccines9030242. [PMID: 33802021 PMCID: PMC7999564 DOI: 10.3390/vaccines9030242] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/04/2021] [Accepted: 03/07/2021] [Indexed: 12/29/2022] Open
Abstract
African swine fever (ASF) is currently the major concern of the global swine industry, as a consequence of which a reconsideration of the containment and prevention measures taken to date is urgently required. A great interest in developing an effective and safe vaccine against ASF virus (ASFV) infection has, therefore, recently appeared. The objective of the present study is to test an inactivated ASFV preparation under a vaccination strategy that has not previously been tested in order to improve its protective effect. The following have been considered: (i) virus inactivation by using a low binary ethyleneimine (BEI) concentration at a low temperature, (ii) the use of new and strong adjuvants; (iii) the use of very high doses (6 × 109 haemadsorption in 50% of infected cultures (HAD50)), and (iv) simultaneous double inoculation by two different routes of administration: intradermal and intramuscular. Five groups of pigs were, therefore, inoculated with BEI- Pol16/DP/OUT21 in different adjuvant formulations, twice with a 4-week interval. Six weeks later, all groups were intramuscularly challenged with 10 HAD50 of the virulent Pol16/DP/OUT21 ASFV isolate. All the animals had clinical signs and pathological findings consistent with ASF. This lack of effectiveness supports the claim that an inactivated virus strategy may not be a viable vaccine option with which to fight ASF.
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74
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Jia R, Zhang G, Liu H, Chen Y, Zhou J, Liu Y, Ding P, Wang Y, Zang W, Wang A. Novel Application of Nanofluidic Chip Digital PCR for Detection of African Swine Fever Virus. Front Vet Sci 2021; 7:621840. [PMID: 33614757 PMCID: PMC7894257 DOI: 10.3389/fvets.2020.621840] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 01/06/2023] Open
Abstract
African swine fever virus (ASFV) gives rise to a grievous transboundary and infectious disease, African swine fever (ASF), which has caused a great economic loss in the swine industry. To prevent and control ASF, once suspicious symptoms have presented, the movement of animal and pork products should be stopped, and then, laboratory testing should be adopted to diagnose ASF. A method for ASFV DNA quantification is presented in this research, which utilizes the next-generation PCR platform, nanofluidic chip digital PCR (cdPCR). The cdPCR detection showed good linearity and repeatability. The limit of detection for cdPCR is 30.1995 copies per reaction, whereas no non-specific amplification curve was found with other swine viruses. In the detection of 69 clinical samples, the cdPCR showed significant consistency [91.30% (63/69)] to the Office International des Epizooties-approved quantitative PCR. Compared with the commercial quantitative PCR kit, the sensitivity of the cdPCR assay was 86.27% (44/50), and the specificity was 94.44% (17/18). The positive coincidence rate of the cdPCR assay was 88% (44/50). The total coincidence rate of the cdPCR and kit was 89.86% (62/69), and the kappa value reached 0.800 (P < 0.0001). This is the first time that cdPCR has been applied to detecting ASFV successfully.
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Affiliation(s)
- Rui Jia
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Hongliang Liu
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou, China.,Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Jingming Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Yankai Liu
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Peiyang Ding
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Yanwei Wang
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Weimin Zang
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
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75
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Development of A Super-Sensitive Diagnostic Method for African Swine Fever Using CRISPR Techniques. Virol Sin 2021; 36:220-230. [PMID: 33411169 DOI: 10.1007/s12250-020-00323-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 10/20/2020] [Indexed: 11/27/2022] Open
Abstract
African swine fever (ASF) is an infectious disease caused by African swine fever virus (ASFV) with clinical symptoms of high fever, hemorrhages and high mortality rate, posing a threat to the global swine industry and food security. Quarantine and control of ASFV is crucial for preventing swine industry from ASFV infection. In this study, a recombinase polymerase amplification (RPA)-CRISPR-based nucleic acid detection method was developed for diagnosing ASF. As a highly sensitive method, RPA-CRISPR can detect even a single copy of ASFV plasmid and genomic DNA by determining fluorescence signal induced by collateral cleavage of CRISPR-lwCas13a (previously known as C2c2) through quantitative real-time PCR (qPCR) and has the same or even higher sensitivity than the traditional qPCR method. A lateral flow strip was developed and used in combination with RPA-CRISPR for ASFV detection with the same level of sensitivity of TaqMan qPCR. Likewise, RPA-CRISPR is capable of distinguishing ASFV genomic DNA from viral DNA/RNA of other porcine viruses without any cross-reactivity. This diagnostic method is also available for diagnosing ASFV clinical DNA samples with coincidence rate of 100% for both ASFV positive and negative samples. RPA-CRISPR has great potential for clinical quarantine of ASFV in swine industry and food security.
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76
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Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble. Pathogens 2020; 9:pathogens9121078. [PMID: 33371523 PMCID: PMC7767518 DOI: 10.3390/pathogens9121078] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/12/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022] Open
Abstract
African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.
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77
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Assessment of Risk Factors of African Swine Fever in India: Perspectives on Future Outbreaks and Control Strategies. Pathogens 2020; 9:pathogens9121044. [PMID: 33322760 PMCID: PMC7763524 DOI: 10.3390/pathogens9121044] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/27/2020] [Accepted: 12/03/2020] [Indexed: 01/02/2023] Open
Abstract
African swine fever (ASF) is one of the most important transboundary diseases of pigs. ASF has been identified in India for the first time in domestic pigs from outbreaks reported in two of the northeastern states, Arunachal Pradesh and Assam in 2020. A total of 11 ASF outbreaks in different regions killed over 3700 pigs and devastated the economy of small-scale livestock owners of both the states. Considering the first outbreak of ASF in India, a generic risk assessment framework was determined to identify potential risk factors that might favor future emergence of the disease. Based on the Indian scenario, we considered population density of host, farming practice, availability of biological vectors and wildlife reservoirs, epidemiological cycles, and international trade to analyze the possibility of future outbreaks of ASF and chances of establishment of endemism. On critical analysis of the identified risk factors associated with ASFV transmission, we observed that the risk factors are well preserved in the Indian geography and might participate in future outbreaks, further disseminating the disease to nearby countries. Since no vaccine is currently available against ASF, the domestic and the wild pigs (wild boars and the endangered pygmy hogs native to India) of this region are under constant threat of infection. For the near future, this region will have to continue to rely on the implementation of preventive measures to avoid the devastating losses that outbreaks can cause. The various adaptive control strategies to minimize the risks associated with the transmission of ASF, keeping our views to Indian settings, have been described. The risk-analysis framework presented in the study will give a further understanding of the dynamics of disease transmission and will help to design control strategies and corresponding measures to minimize the catastrophic consequences of ASF disease.
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78
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Feng Z, Chen J, Liang W, Chen W, Li Z, Chen Q, Cai S. The recombinant pseudorabies virus expressing African swine fever virus CD2v protein is safe and effective in mice. Virol J 2020; 17:180. [PMID: 33198749 PMCID: PMC7668019 DOI: 10.1186/s12985-020-01450-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 11/05/2020] [Indexed: 12/14/2022] Open
Abstract
Background African swine fever (ASF) leads to high mortality in domestic pigs and wild boar and is caused by the African swine fever virus (ASFV). Currently, no vaccine is commercially available for prevention, and the epidemic is still spreading. Here, we constructed a recombinant pseudorabies virus (PRV) (PRV-ΔgE/ΔgI/ΔTK-(CD2v)) that expresses the CD2v protein of ASFV and evaluated its effectiveness and safety as a vaccine candidate in mice. Methods A homologous recombination fragment containing ASFV CD2v was synthesized and co-transfected into HEK 293 T cells, a knockout vector targeting the PRV TK gene. The transfected cells were infected with PRV-ΔgE/ΔgI, and the recombinant strain (PRV-ΔgE/ΔgI/ΔTK-(CD2v)) was obtained by plaque purification in Vero cells. The expression of ASFV CD2v in the recombinant virus was confirmed by sequencing, Western blotting, and immunofluorescence analysis, and the genetic stability was tested in Vero cells over 20 passages. The virulence, immunogenicity and protective ability of the recombinant virus were further tested in a mouse model. Results The PRV-ΔgE/ΔgI/ΔTK-(CD2v) recombinant strain is stable in Vero cells, and the processing of CD2v does not depend on ASFV infection. The vaccination of PRV-ΔgE/ΔgI/ΔTK-(CD2v) causes neither pruritus, not a systemic infection and inflammation (with the high expression of interleukin-6 (IL6)). Besides, the virus vaccination can produce anti-CD2v specific antibody and activate a specific cellular immune response, and 100% protect mice from the challenge of the virulent strain (PRV-Fa). The detoxification occurs much earlier upon the recombinant virus vaccination and the amount of detoxification is much lower as well. Conclusions The PRV-ΔgE/ΔgI/ΔTK-(CD2v) recombinant strain has strong immunogenicity, is safe and effective, and maybe a potential vaccine candidate for the prevention of ASF and Pseudorabies.
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Affiliation(s)
- Zhihua Feng
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China
| | - Jianghua Chen
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China
| | - Wangwang Liang
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China
| | - Wenzhi Chen
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China
| | - Zhaolong Li
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China. .,Institute of Animal Husbandry and Veterinary Medicine, Fujian Province, Fujian Academy of Agricultural Sciences, Pudang, Jin-an District, Fuzhou, 350117, People's Republic of China.
| | - Qi Chen
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China.
| | - Shaoli Cai
- Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, Fujian Province, Fujian Normal University Qishan Campus, College Town, Fuzhou, 350117, People's Republic of China.
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79
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Wang T, Sun Y, Huang S, Qiu HJ. Multifaceted Immune Responses to African Swine Fever Virus: Implications for Vaccine Development. Vet Microbiol 2020; 249:108832. [PMID: 32932135 DOI: 10.1016/j.vetmic.2020.108832] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/23/2020] [Indexed: 12/13/2022]
Abstract
African swine fever (ASF) is a highly contagious, often fatal viral disease caused by African swine fever virus (ASFV), leading to high fever, severe hemorrhages with high lethality in domestic pigs and wild boar. In 2007, ASF was reintroduced into Europe. Since then, ASF has spread to many European and Asian countries and now becomes a major concern to the swine industry worldwide. There have been various vaccine attempts, but no commercial ASF vaccines are available so far. A key hurdle in developing a safe and efficacious ASF vaccine is the limited understanding of innate and adaptive immune responses elicited by ASFV infection. Though several promising vaccine candidates have been described, more key scientific challenges remain unsolved. Here, we provide an overview of the current knowledge in innate and adaptive immune responses elicited by ASFV infection and different kinds of vaccine candidates. Additionally, the applications and prospects of vaccine candidates are discussed. Finally, we highlight the implications of these mechanisms for rational design of ASF vaccines.
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Affiliation(s)
- Tao Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Shujian Huang
- School of Life Engineering, Foshan University, Foshan 528231, China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; School of Life Engineering, Foshan University, Foshan 528231, China.
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80
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Yoo D, Kim H, Lee JY, Yoo HS. African swine fever: Etiology, epidemiological status in Korea, and perspective on control. J Vet Sci 2020; 21:e38. [PMID: 32233141 PMCID: PMC7113569 DOI: 10.4142/jvs.2020.21.e38] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 12/22/2022] Open
Abstract
African swine fever (ASF), caused by the ASF virus, a member of the Asfarviridae family, is one of the most important diseases in the swine industry due to its clinical and economic impacts. Since the first report of ASF a century ago, ample information has become available, but prevention and treatment measures are still inadequate. Two waves of epizootic outbreaks have occurred worldwide. While the first wave of the epizootic outbreak was controlled in most of the infected areas, the second wave is currently active in the European and Asian continents, causing severe economic losses to the pig industry. There are different patterns of spreading in the outbreaks between those in European and Asian countries. Prevention and control of ASF are very difficult due to the lack of available vaccines and effective therapeutic measures. However, recent outbreaks in South Korea have been successfully controlled on swine farms, although feral pigs are periodically being found to be positive for the ASF virus. Therefore, we would like to share our story regarding the preparation and application of control measures. The success in controlling ASF on farms in South Korea is largely due to the awareness and education of swine farmers and practitioners, the early detection of infected animals, the implementation of strict control policies by the government, and widespread sharing of information among stakeholders. Based on the experience gained from the outbreaks in South Korea, this review describes the current understanding of the ASF virus and its pathogenic mechanisms, epidemiology, and control.
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Affiliation(s)
- Dongwan Yoo
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois-Urbana-Champaign, Urbana, IL 61802, USA.,Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | | | - Joo Young Lee
- Choong Ang Vaccine Laboratories Co. (Ltd.), Daejeon 34055, Korea
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
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81
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Wu K, Liu J, Wang L, Fan S, Li Z, Li Y, Yi L, Ding H, Zhao M, Chen J. Current State of Global African Swine Fever Vaccine Development under the Prevalence and Transmission of ASF in China. Vaccines (Basel) 2020; 8:vaccines8030531. [PMID: 32942741 PMCID: PMC7564663 DOI: 10.3390/vaccines8030531] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 11/29/2022] Open
Abstract
African swine fever (ASF) is a highly lethal contagious disease of swine caused by African swine fever virus (ASFV). At present, it is listed as a notifiable disease reported to the World Organization for Animal Health (OIE) and a class one animal disease ruled by Chinese government. ASF has brought significant economic losses to the pig industry since its outbreak in China in August 2018. In this review, we recapitulated the epidemic situation of ASF in China as of July 2020 and analyzed the influencing factors during its transmission. Since the situation facing the prevention, control, and eradication of ASF in China is not optimistic, safe and effective vaccines are urgently needed. In light of the continuous development of ASF vaccines in the world, the current scenarios and evolving trends of ASF vaccines are emphatically analyzed in the latter part of the review. The latest research outcomes showed that attempts on ASF gene-deleted vaccines and virus-vectored vaccines have proven to provide complete homologous protection with promising efficacy. Moreover, gaps and future research directions of ASF vaccine are also discussed.
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Affiliation(s)
- Keke Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Jiameng Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Lianxiang Wang
- Hog Production Division, Guangdong Wen2019s Foodstuffs Group Co, Ltd., Xinxing 527439, China;
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Zhaoyao Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Yuwan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Lin Yi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Hongxing Ding
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (K.W.); (J.L.); (S.F.); (Z.L.); (Y.L.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Correspondence: ; Fax: +86-20-8528-0245
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82
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Flannery J, Moore R, Marsella L, Harris K, Ashby M, Rajko-Nenow P, Roberts H, Gubbins S, Batten C. Towards a Sampling Rationale for African Swine Fever Virus Detection in Pork Products. Foods 2020; 9:E1148. [PMID: 32825271 PMCID: PMC7554881 DOI: 10.3390/foods9091148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 12/02/2022] Open
Abstract
African swine fever (ASF) is a highly lethal disease of pigs caused by the ASF virus (ASFV), which presents a serious threat to global food security. The movement of contaminated pork products has previously been postulated as contributing to the introduction of ASF into new areas. To evaluate the performance of ASFV detection systems in multi-component pork products, we spiked sausage meat with four different ASFV-containing materials (ASFV cell culture, pork loin, meat juice and bone marrow). DNA was extracted using two manual systems (MagMAX CORE, Qiagen) and one automated (MagMAX CORE) one, and three qPCR assays (VetMAX, King, UPL) were used. The performance of the DNA extraction systems was as follows; automated MagMAX > manual MagMAX > manual Qiagen. The commercial VetMAX qPCR assay yielded significantly lower CT values (p < 0.001), showing greater sensitivity than the World Organization for Animal Health (OIE)-prescribed assays (King, UPL). Detection probability was the highest for matrices contaminated with bone marrow compared with pork loin or meat juice. An estimated minimum sample size of one 1-g sample is sufficient to detect ASFV in a homogenous pork product if bone marrow from infected pigs comprises 1 part in 10,000. We demonstrated that existing ASFV detection systems are appropriate for use in a food-testing capacity, which can provide an additional control measure for ASF.
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Affiliation(s)
- John Flannery
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Rebecca Moore
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Laura Marsella
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Katie Harris
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Martin Ashby
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Paulina Rajko-Nenow
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Helen Roberts
- Defra, Nobel House, 17 Smith Square, London SW1P 3JR, UK;
| | - Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
| | - Carrie Batten
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK; (R.M.); (L.M.); (K.H.); (M.A.); (P.R.-N.); (S.G.); (C.B.)
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83
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Goatley LC, Reis AL, Portugal R, Goldswain H, Shimmon GL, Hargreaves Z, Ho CS, Montoya M, Sánchez-Cordón PJ, Taylor G, Dixon LK, Netherton CL. A Pool of Eight Virally Vectored African Swine Fever Antigens Protect Pigs Against Fatal Disease. Vaccines (Basel) 2020; 8:E234. [PMID: 32443536 PMCID: PMC7349991 DOI: 10.3390/vaccines8020234] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/01/2020] [Accepted: 05/14/2020] [Indexed: 01/08/2023] Open
Abstract
Classical approaches to African swine fever virus (ASFV) vaccine development have not been successful; inactivated virus does not provide protection and use of live attenuated viruses generated by passage in tissue culture had a poor safety profile. Current African swine fever (ASF) vaccine research focuses on the development of modified live viruses by targeted gene deletion or subunit vaccines. The latter approach would be differentiation of vaccinated from infected animals (DIVA)-compliant, but information on which viral proteins to include in a subunit vaccine is lacking. Our previous work used DNA-prime/vaccinia-virus boost to screen 40 ASFV genes for immunogenicity, however this immunization regime did not protect animals after challenge. Here we describe the induction of both antigen and ASFV-specific antibody and cellular immune responses by different viral-vectored pools of antigens selected based on their immunogenicity in pigs. Immunization with one of these pools, comprising eight viral-vectored ASFV genes, protected 100% of pigs from fatal disease after challenge with a normally lethal dose of virulent ASFV. This data provide the basis for the further development of a subunit vaccine against this devastating disease.
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Affiliation(s)
- Lynnette C. Goatley
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Ana Luisa Reis
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Raquel Portugal
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Hannah Goldswain
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Gareth L. Shimmon
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Zoe Hargreaves
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Chak-Sum Ho
- Gift of Hope Organ and Tissue Donor Network, Itasca, IL 60143, USA;
| | - María Montoya
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Pedro J. Sánchez-Cordón
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Geraldine Taylor
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Linda K. Dixon
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
| | - Christopher L. Netherton
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; (L.C.G.); (A.L.R.); (R.P.); (H.G.); (G.L.S.); (Z.H.); (M.M.); (P.J.S.-C.); (G.T.); (L.K.D.)
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84
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Gaudreault NN, Madden DW, Wilson WC, Trujillo JD, Richt JA. African Swine Fever Virus: An Emerging DNA Arbovirus. Front Vet Sci 2020; 7:215. [PMID: 32478103 PMCID: PMC7237725 DOI: 10.3389/fvets.2020.00215] [Citation(s) in RCA: 191] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
African swine fever virus (ASFV) is the sole member of the family Asfarviridae, and the only known DNA arbovirus. Since its identification in Kenya in 1921, ASFV has remained endemic in Africa, maintained in a sylvatic cycle between Ornithodoros soft ticks and warthogs (Phacochoerus africanus) which do not develop clinical disease with ASFV infection. However, ASFV causes a devastating and economically significant disease of domestic (Sus scrofa domesticus) and feral (Sus scrofa ferus) swine. There is no ASFV vaccine available, and current control measures consist of strict animal quarantine and culling procedures. The virus is highly stable and easily spreads by infected swine, contaminated pork products and fomites, or via transmission by the Ornithodoros vector. Competent Ornithodoros argasid soft tick vectors are known to exist not only in Africa, but also in parts of Europe and the Americas. Once ASFV is established in the argasid soft tick vector, eradication can be difficult due to the long lifespan of Ornithodoros ticks and their proclivity to inhabit the burrows of warthogs or pens and shelters of domestic pigs. Establishment of endemic ASFV infections in wild boar populations further complicates the control of ASF. Between the late 1950s and early 1980s, ASFV emerged in Europe, Russia and South America, but was mostly eradicated by the mid-1990s. In 2007, a highly virulent genotype II ASFV strain emerged in the Caucasus region and subsequently spread into the Russian Federation and Europe, where it has continued to circulate and spread. Most recently, ASFV emerged in China and has now spread to several neighboring countries in Southeast Asia. The high morbidity and mortality associated with ASFV, the lack of an efficacious vaccine, and the complex makeup of the ASFV virion and genome as well as its lifecycle, make this pathogen a serious threat to the global swine industry and national economies. Topics covered by this review include factors important for ASFV infection, replication, maintenance, and transmission, with attention to the role of the argasid tick vector and the sylvatic transmission cycle, current and future control strategies for ASF, and knowledge gaps regarding the virus itself, its vector and host species.
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Affiliation(s)
- Natasha N. Gaudreault
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Daniel W. Madden
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - William C. Wilson
- Arthropod Borne Animal Diseases Research Unit, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, United States
| | - Jessie D. Trujillo
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Juergen A. Richt
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
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85
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Sang H, Miller G, Lokhandwala S, Sangewar N, Waghela SD, Bishop RP, Mwangi W. Progress Toward Development of Effective and Safe African Swine Fever Virus Vaccines. Front Vet Sci 2020; 7:84. [PMID: 32154279 PMCID: PMC7047163 DOI: 10.3389/fvets.2020.00084] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 02/03/2020] [Indexed: 12/18/2022] Open
Abstract
African swine fever is a major concern due to its negative impact on pork production in affected regions. Due to lack of treatment and a safe vaccine, it has been extremely difficult to control this devastating disease. The mechanisms of virus entry, replication within the host cells, immune evasion mechanisms, correlates of protection, and antigens that are effective at inducing host immune response, are now gradually being identified. This information is required for rational design of novel disease control strategies. Pigs which recover from infection with less virulent ASFV isolates can be protected from challenge with related virulent isolates. This strongly indicates that an effective vaccine against ASFV could be developed. Nonetheless, it is clear that effective immunity depends on both antibody and cellular immune responses. This review paper summarizes the key studies that have evaluated three major approaches for development of African Swine Fever virus vaccines. Recent immunization strategies have involved development and in vivo evaluation of live attenuated virus, and recombinant protein- and DNA-based and virus-vectored subunit vaccine candidates. The limitations of challenge models for evaluating ASFV vaccine candidates are also discussed.
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Affiliation(s)
- Huldah Sang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Gabrielle Miller
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Shehnaz Lokhandwala
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Neha Sangewar
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Suryakant D. Waghela
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, United States
| | - Richard P. Bishop
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Waithaka Mwangi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
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86
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Wang A, Jia R, Liu Y, Zhou J, Qi Y, Chen Y, Liu D, Zhao J, Shi H, Zhang J, Zhang G. Development of a novel quantitative real-time PCR assay with lyophilized powder reagent to detect African swine fever virus in blood samples of domestic pigs in China. Transbound Emerg Dis 2019; 67:284-297. [PMID: 31483566 DOI: 10.1111/tbed.13350] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 08/23/2019] [Accepted: 08/24/2019] [Indexed: 12/17/2022]
Abstract
African swine fever (ASF) is a devastating disease, which is causing huge economic losses in China. Therefore, it is urgent to provide a rapid, highly specific and sensitive diagnostic method for the detection of African swine fever virus (ASFV), the ASF infectious agent. In this study, a novel quantitative real-time polymerase chain reaction (qPCR) assay with lyophilized powder reagents (LPR), targeting the major structural protein p72 gene, was established for the detection of ASFV. This assay had many advantages, such as saving time and money, good sensitivity and repeatability. The sensitivity of this assay was 100 copies/μl of ASFV plasmid templates, and the assay showed 10-fold greater sensitivity than a qPCR assay recommended by OIE. Furthermore, specificity analysis showed that qPCR with LPR for ASFV had no cross-reactivity with other important swine pathogens. In clinical diagnoses of 218 blood samples of domestic pigs in China, the positive rate of the diagnosis of ASFV by qPCR with the LPR and commercial kit reached 80.73% (176/218) and 76.61% (167/218) respectively. The coincidence rate between the two assays is 92.20% (201/218), and kappa value is 0.768 (p < .0001) by SPSS analysis. The overall agreement between the two assays was 95.87% (209/218). Further Pearson correlation and linear regression analysis showed a significant correlation between the two assays with an R2 value of 0.9438. The entire procedure, from specimen processing to result reporting, can be completed within 2 hr. Our results demonstrated that the qPCR-LPR assay is a good laboratory diagnostic tool for sensitive and efficient detection of ASFV.
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Affiliation(s)
- Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Rui Jia
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Yunchao Liu
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Jingming Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Yuanming Qi
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Dongmin Liu
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Jianguo Zhao
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Haining Shi
- Henan Zhongze Biological Engineering Co. LTD, Zhengzhou, China
| | - Jing Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
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