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Dundon WG, Molini U, Franzo G. Six underreported viral diseases of domesticated and wild swine in Africa: Implications and perspectives. Vet Microbiol 2024; 294:110120. [PMID: 38749211 DOI: 10.1016/j.vetmic.2024.110120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 06/11/2024]
Abstract
Pig production is increasing annually in Africa as it is recognized as a significant source of income, livelihood and food security, particularly in rural communities. Understanding the circulating swine pathogens is crucial for the success of this emerging industry. Although there is extensive data available on the African swine fever virus due to its devastating impact on pig production, knowledge about the presence of other viral swine pathogens on the continent is still extremely limited. This review discusses what is currently known about six swine pathogens in Africa: classical swine fever virus, porcine reproductive and respiratory syndrome virus, porcine circovirus-2, porcine circovirus-3, porcine parvovirus-1, and pseudorabies virus. Gaps in our knowledge are identified and topics of future focus discussed.
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Affiliation(s)
- William G Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Center, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, Vienna 1400, Austria.
| | - Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia; Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek, Namibia
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Legnaro, viale dell'Università 16, 35020, Italy
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2
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Spinard E, Wade A, Unger H, Robert N, Mayega FJ, Sreenu VB, Da Silva Filpe A, Mair D, Borca MV, Gladue DP, Masembe C. Near-complete genome sequences of multiple genotype 1 African swine fever virus isolates from 2016 to 2018 in Cameroon. Microbiol Resour Announc 2024; 13:e0097823. [PMID: 38477459 PMCID: PMC11008206 DOI: 10.1128/mra.00978-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
African swine fever virus has been endemic in Cameroon since 1982. Here, we announce the sequences of Cameroon/2016/C1, Cameroon/2016/C5, Cameroon/2017/C-A2, Cameroon/2018/C02, and Cameroon/2018/CF3, five genotype 1 African swine fever virus genomes collected from domestic pigs between 2016 and 2018.
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Affiliation(s)
- Edward Spinard
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, New York, USA
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, Kansas, USA
| | - Abel Wade
- National Veterinary Laboratory (LANAVET), Garoua, Cameroon
| | - Hermann Unger
- Animal Production and Health Section, Joint FAO/IAEA Division for Nuclear Applications in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Vienna, Austria
| | - Nenkam Robert
- Laboratoire National Veterinaire (LANAVET), Garoua, Cameroon
| | | | | | - Ana Da Silva Filpe
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Daniel Mair
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Manuel V. Borca
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, New York, USA
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, Kansas, USA
| | - Douglas P. Gladue
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Orient, New York, USA
- U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, National Bio and Agro-Defense Facility, Unit Name, Manhattan, Kansas, USA
| | - Charles Masembe
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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Ogundijo OA, Omotosho OO, Al-Mustapha AI, Abiola JO, Awosanya EJ, Odukoya A, Owoicho S, Oyewo M, Ibrahim A, Orum TG, Nanven MB, Bolajoko MB, Luka P, Adeyemo OK. A multi-state survey of farm-level preparedness towards African swine fever outbreak in Nigeria. Acta Trop 2023; 246:106989. [PMID: 37507080 DOI: 10.1016/j.actatropica.2023.106989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/04/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023]
Abstract
Outbreaks of African Swine Fever (ASF) have severe economic implications for Nigeria and result in significant loss of livelihoods. The non-availability of vaccines makes biosecurity the reliable key to reducing ASF outbreaks. This study evaluated preparedness for ASF outbreaks at the farm level among 247 pig farmers randomly selected from Abia, Akwa-Ibom, Edo, Kwara, and Oyo states. We categorized each pig farmer's ASF preparedness rating (ASF - PR) as "poor", "moderate", and "satisfactory" based on their score on an 11-item scale. Finally, a multivariable logistic regression analysis was conducted to assess the association between the socio-demographic variables and farm-level ASF preparedness. The awareness of ASF among pig farmers was very high (87.9%, n = 217). Most farmers knew the clinical signs of the disease, the modes of transmission of ASF, and correctly identified the risk factors. They also considered the need for thorough cleaning and disinfection of piggeries (87.1%, n = 189), tightened biosecurity (85.7%, n = 186), culling all ASF-affected pigs (77.9%, n = 169) as well as the ban on the transport of pigs and their products (49.8%, n = 108) as very important in ASF control. Conversely, 27.6%, (n = 60) of the farmers thought ASF could affect humans, 12% (n = 27) of them openly discarded the carcasses of dead pigs, and there was a high antibiotic usage. Most of the pig farmers used antibiotics as prophylaxis (63.6%, n = 157), chemotherapeutics (66.4%, n = 164), growth promoters (15.4%, n = 38), and wrongly so, 13% (n = 32) of them thought that antibiotics could be used to prevent and treat ASF. At the farm level, two-thirds (68.8%, n = 170) of the farmers had strict movement restrictions, and 48.6% (n = 120) routinely quarantine new pigs before introduction into their herd. Across the five states, 36% (n = 89) of the farmers had witnessed sudden death with signs consistent with ASF amongst their pigs and only 10.1% (n = 27) had confirmatory ASF diagnosis. The mean score for the farm-level ASF-PR was 6.95 ± 2.7. Approximately one-quarter of the 247 pig farmers had satisfactory ASF - PR that might help to prevent the incursion of ASF into their farms. Most farmers had moderate ASF - PR (59.5%, n = 147) whereas 17% (n = 42) had very poor ASF-PR and were most prone to an ASF outbreak. Of the sociodemographic variables, only age was significantly associated with farm-level ASF preparedness as older pig farmers especially those aged between 50 and 59 years (OR: 4.83; 95% CI: 1.10, 21.22; p = 0.037) were more likely to have satisfactory ASF - PR than the others. Our findings showed pig farmers were not adequately prepared and the next ASF outbreak could pose more significant threat to pig populations across Nigeria. Government should urgently establish minimum biosecurity measures and improve its ASF surveillance mechanisms for commercial and backyard pig production.
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Affiliation(s)
- Oluwaseun A Ogundijo
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria
| | - Oladipo O Omotosho
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria
| | - Ahmad I Al-Mustapha
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria; Department of Veterinary Services, Kwara State Ministry of Agriculture and Rural Development, Ilorin, Kwara State, Nigeria; Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Finland.
| | - John O Abiola
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria
| | - Emmanuel J Awosanya
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria
| | - Adesoji Odukoya
- Federal Ministry of Agriculture and Rural Development, Abuja, Nigeria; Nigerian Field Epidemiology and Laboratory Training program, Abuja, Nigeria
| | - Samuel Owoicho
- Federal Ministry of Agriculture and Rural Development, Abuja, Nigeria; Nigerian Field Epidemiology and Laboratory Training program, Abuja, Nigeria
| | - Muftau Oyewo
- Department of Veterinary Services, Kwara State Ministry of Agriculture and Rural Development, Ilorin, Kwara State, Nigeria; Nigerian Field Epidemiology and Laboratory Training program, Abuja, Nigeria
| | - Ahmed Ibrahim
- Department of Veterinary Services, Kwara State Ministry of Agriculture and Rural Development, Ilorin, Kwara State, Nigeria
| | - Terese G Orum
- Regional Disease Surveillance Systems Enhancement Project, Abuja, Nigeria
| | - Magdalene B Nanven
- Nigerian Field Epidemiology and Laboratory Training program, Abuja, Nigeria
| | | | - Pam Luka
- National Veterinary Research Institute, Vom, Plateau State, Nigeria
| | - Olanike K Adeyemo
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria
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Pakotiprapha D, Kuhaudomlarp S, Tinikul R, Chanarat S. Bridging the Gap: Can COVID-19 Research Help Combat African Swine Fever? Viruses 2023; 15:1925. [PMID: 37766331 PMCID: PMC10536364 DOI: 10.3390/v15091925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/12/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
African swine fever (ASF) is a highly contagious and economically devastating disease affecting domestic pigs and wild boar, caused by African swine fever virus (ASFV). Despite being harmless to humans, ASF poses significant challenges to the swine industry, due to sudden losses and trade restrictions. The ongoing COVID-19 pandemic has spurred an unparalleled global research effort, yielding remarkable advancements across scientific disciplines. In this review, we explore the potential technological spillover from COVID-19 research into ASF. Specifically, we assess the applicability of the diagnostic tools, vaccine development strategies, and biosecurity measures developed for COVID-19 for combating ASF. Additionally, we discuss the lessons learned from the pandemic in terms of surveillance systems and their implications for managing ASF. By bridging the gap between COVID-19 and ASF research, we highlight the potential for interdisciplinary collaboration and technological spillovers in the battle against ASF.
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Affiliation(s)
| | | | | | - Sittinan Chanarat
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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Zajac MD, Trujillo JD, Yao J, Kumar R, Sangewar N, Lokhandwala S, Sang H, Mallen K, McCall J, Burton L, Kumar D, Heitmann E, Burnum T, Waghela SD, Almes K, Richt J, Kim T, Mwangi W. Immunization of pigs with replication-incompetent adenovirus-vectored African swine fever virus multi-antigens induced humoral immune responses but no protection following contact challenge. Front Vet Sci 2023; 10:1208275. [PMID: 37404778 PMCID: PMC10316028 DOI: 10.3389/fvets.2023.1208275] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/30/2023] [Indexed: 07/06/2023] Open
Abstract
Introduction African swine fever virus (ASFV) is a pathogen of great economic importance given that continues to threaten the pork industry worldwide, but there is no safe vaccine or treatment available. Development of a vaccine is feasible as immunization of pigs with some live attenuated ASFV vaccine candidates can confer protection, but safety concerns and virus scalability are challenges that must to be addressed. Identification of protective ASFV antigens is needed to inform the development of efficacious subunit vaccines. Methods In this study, replication-incompetent adenovirus-vectored multicistronic ASFV antigen expression constructs that covered nearly 100% of the ASFV proteome were generated and validated using ASFV convalescent serum. Swine were immunized with a cocktail of the expression constructs, designated Ad5-ASFV, alone or formulated with either Montanide ISA-201™ (ASFV-ISA-201) or BioMize® adjuvant (ASFV-BioMize). Results These constructs primed strong B cell responses as judged by anti-pp62-specific IgG responses. Notably, the Ad5-ASFV and the Ad5-ASFV ISA-201, but not the Ad5-ASFV BioMize®, immunogens primed significantly (p < 0.0001) higher anti-pp62-specific IgG responses compared with Ad5-Luciferase formulated with Montanide ISA-201™ adjuvant (Luc-ISA-201). The anti-pp62-specific IgG responses underwent significant (p < 0.0001) recall in all the vaccinees after boosting and the induced antibodies strongly recognized ASFV (Georgia 2007/1)-infected primary swine cells. However, following challenge by contact spreaders, only one pig nearly immunized with the Ad5-ASFV cocktail survived. The survivor had no typical clinical symptoms, but had viral loads and lesions consistent with chronic ASF. Discussion Besides the limited sample size used, the outcome suggests that in vivo antigen expression, but not the antigen content, might be the limitation of this immunization approach as the replication-incompetent adenovirus does not amplify in vivo to effectively prime and expand protective immunity or directly mimic the gene transcription mechanisms of attenuated ASFV. Addressing the in vivo antigen delivery limitations may yield promising outcomes.
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Affiliation(s)
- Michelle D. Zajac
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Jessie D. Trujillo
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Jianxiu Yao
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Rakshith Kumar
- 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
| | - Shehnaz Lokhandwala
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Huldah Sang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Kylynn Mallen
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Jayden McCall
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Leeanna Burton
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Deepak Kumar
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Emily Heitmann
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Tristan Burnum
- 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
| | - Kelli Almes
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Juergen Richt
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Tae Kim
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Waithaka Mwangi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
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Penrith ML, Van Heerden J, Heath L, Abworo EO, Bastos ADS. Review of the Pig-Adapted African Swine Fever Viruses in and Outside Africa. Pathogens 2022; 11:pathogens11101190. [PMID: 36297247 PMCID: PMC9609104 DOI: 10.3390/pathogens11101190] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/08/2022] [Accepted: 10/11/2022] [Indexed: 12/04/2022] Open
Abstract
The region in eastern, central and southern Africa (ECSA) where African swine fever (ASF) originated in a sylvatic cycle is home to all the p72 genotypes of ASF virus identified so far. While 20 of the 24 genotypes have been isolated from outbreaks in domestic pigs in the region, only five of the genotypes (I, II, VIII, IX, X) have an extended field presence associated with domestic pigs. Of the genotypes that appear to be strongly adapted to domestic pigs, two have spread beyond the African continent and have been the focus of efforts to develop vaccines against ASF. Most of the experimental ASF vaccines described do not protect against a wider spectrum of viruses and may be less useful in the event of incursions of different strains or where multiple genotypes co-exist. The other three pig-adapted strains that are currently restricted to the ECSA region might spread, and priority should be given to understanding not only the genetic and antigenic characteristics of these viruses but also their history. We review historic and current knowledge of the distribution of these five virus genotypes, and note that as was the case for genotype II, some pig-associated viruses have the propensity for geographical range expansion. These features are valuable for prioritizing vaccine-development efforts to ensure a swift response to virus escape. However, whilst ASF vaccines are critical for high-production systems, global food security relies on parallel efforts to improve biosecurity and pig production in Africa and on continued ASFV surveillance and characterisation in the ECSA region.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa
- Correspondence: or
| | - Juanita Van Heerden
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
| | - Livio Heath
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
| | - Edward Okoth Abworo
- Biosciences, Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi 00100, Kenya
| | - Armanda D. S. Bastos
- Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa
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Nga BTT, Padungtod P, Depner K, Chuong VD, Duy DT, Anh ND, Dietze K. Implications of partial culling on African swine fever control effectiveness in Vietnam. Front Vet Sci 2022; 9:957918. [PMID: 36118335 PMCID: PMC9479321 DOI: 10.3389/fvets.2022.957918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/08/2022] [Indexed: 11/25/2022] Open
Abstract
The introduction of the African swine fever (ASF) into previously unaffected countries often overwhelms veterinary authorities with the resource demanding control efforts that need to be undertaken. The approach of implementing total stamping out of affected herds is taken as “default” control measure in many countries, regardless of the transboundary animal disease addressed, leading to a variety of challenges when implemented. Apart from the organizational challenges and high demand for human and financial resources, the total stamping out approach puts a high burden on the livelihoods of the affected farmers. After the spread of ASF throughout the country in 2019, Vietnam changed the culling approach enabling partial culling of only affected animals in the herd, in order to save resources, and reduce the environmental impact because of the carcass disposal and allow farmers to protect valuable assets. Until now, field data comparing these disease control options in their performance during implementation has not been evaluated scientifically. Analyzing the effect of the change in a control policy, the present study concludes that partial culling can on average save over 50% of total stock with an 8-day prolongation of the implementation of control measures. With 58% of farms undergoing partial culling scoring high on a time-livelihoods matrix, while total stamping out fails to score on livelihoods, much-needed clarity on the livelihood-protecting effects of alternative culling strategies is given. In the future, this will allow veterinary authorities to adjust control measures according to differing priorities, targeting peculiarities of ASF and acknowledging resource constraints faced.
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Affiliation(s)
- Bui Thi To Nga
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Pawin Padungtod
- Food and Agriculture Organization of the United Nations (FAO), Country Office for Vietnam, Hanoi, Vietnam
| | - Klaus Depner
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Vo Dinh Chuong
- Department of Animal Health, Ministry of Agriculture and Rural Development, Hanoi, Vietnam
| | - Do Tien Duy
- Department of Infectious Diseases and Veterinary Public Health, Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam
| | - Nguyen Duc Anh
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Klaas Dietze
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Greifswald, Germany
- *Correspondence: Klaas Dietze
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Shi K, Liu H, Yin Y, Si H, Long F, Feng S. Molecular Characterization of African Swine Fever Virus From 2019-2020 Outbreaks in Guangxi Province, Southern China. Front Vet Sci 2022; 9:912224. [PMID: 35782548 PMCID: PMC9240437 DOI: 10.3389/fvets.2022.912224] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
African swine fever virus (ASFV) causes contagious hemorrhagic disease of pigs with high morbidity and mortality. To identify the molecular characteristics of ASFV strains circulating in Guangxi province, southern China, a total of 336 tissue samples collected from 336 domestic pigs that died as a result of severe hemorrhagic disease during 2019–2020 were tested for ASFV. Furthermore, 66 ASFV strains were genetically characterized by sequence analysis of the C-terminal region of B646L (p72) gene, the complete E183L (p54) gene, the variable region of EP402R (CD2v) gene, the central variable region (CVR) of B602L gene, the full MGF505-2R gene, and the tandem repeat sequence (TRS) within intergenic region (IGR) between the I73R and I329L (I73R/I329L) genes. Phylogenetic analysis revealed that the ASFV strains from Guangxi province belonged to genotypes I and II based on the B646L (p72) and E183L (p54) genes, and there were eight different tetrameric TRS variants based on the CVR of B602L gene. Phylogenetic analysis of the EP402R (CD2v) gene revealed that these ASFV strains belonged to serogroups 4 and 8. Eight of the 66 strains belonged to genotype I and serogroup 4, and showed deletion of whole MGF505-2R gene. The sequence analysis of the IGR between the I73R/I329L genes showed that IGR II and III variants were co-circulating in Guangxi province. The results indicated that ASFV strains circulating in Guangxi province during 2019–2020 outbreaks showed high genetic diversity, of which genotypes I and II, as well as serogroups 4 and 8, were simultaneously circulating in Guangxi province, and there existed wild-type and naturally gene-deleted strains in the field. This is the first detailed report on the molecular characterization of the ASFV strains circulating in southern China, and serogroup 4 in China.
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Affiliation(s)
- Kaichuang Shi
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
- College of Animal Science and Technology, Guangxi University, Nanning, China
- *Correspondence: Kaichuang Shi
| | - Huixin Liu
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Yanwen Yin
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Hongbin Si
- College of Animal Science and Technology, Guangxi University, Nanning, China
- Hongbin Si
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
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Zajac MD, Sangewar N, Lokhandwala S, Bray J, Sang H, McCall J, Bishop RP, Waghela SD, Kumar R, Kim T, Mwangi W. Adenovirus-Vectored African Swine Fever Virus pp220 Induces Robust Antibody, IFN-γ, and CTL Responses in Pigs. Front Vet Sci 2022; 9:921481. [PMID: 35711803 PMCID: PMC9195138 DOI: 10.3389/fvets.2022.921481] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
African Swine Fever Virus (ASFV) poses a serious threat to the pork industry worldwide; however, there is no safe vaccine or treatment available. The development of an efficacious subunit vaccine will require the identification of protective antigens. The ASFV pp220 polyprotein is essential for virus structural integrity. This polyprotein is processed to generate p5, p34, p14, p37, and p150 individual proteins. Immunization of pigs with a cocktail of adenoviruses expressing the proteins induced significant IgG, IFN-γ-secreting cells, and cytotoxic T lymphocyte responses. Four predicted SLA-I binding nonamer peptides, namely p34161−169, p37859−867, p1501363−1371, and p1501463−1471, recalled strong IFN-γ+ PBMC and splenocyte responses. Notably, peptide p34161−169 was recognized by PBMCs isolated from 7/10 pigs and by splenocytes isolated from 8/10 pigs. Peptides p37859−867 and p1501363−1371 stimulated recall IFN-γ+ responses in PBMCs and splenocytes isolated from 8/10 pigs, whereas peptide p1501463−1471 recalled responses in PBMCs and splenocytes isolated from 7/10 to 9/10 pigs, respectively. The results demonstrate that the pp220 polyprotein contains multiple epitopes that induce robust immune responses in pigs. Importantly, these epitopes are 100% conserved among different ASFV genotypes and were predicted to bind multiple SLA-I alleles. The outcomes suggest that pp220 is a promising candidate for inclusion in a prototype subunit vaccine.
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Affiliation(s)
- Michelle D. Zajac
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
- *Correspondence: Michelle D. Zajac
| | - Neha Sangewar
- 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
| | - Jocelyne Bray
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, United States
| | - Huldah Sang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Jayden McCall
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Richard P. Bishop
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Suryakant D. Waghela
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, United States
| | - Rakshith Kumar
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Tae Kim
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Waithaka Mwangi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
- Waithaka Mwangi
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