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Chen YS, Lee CY, Wu CC, Kao PL, Chen TA, Huang Y, Chung WB, Kuo TY, Chen C. Efficacy evaluation of a bivalent subunit vaccine against classical swine fever virus and porcine circovirus type 2. Sci Rep 2024; 14:2997. [PMID: 38316873 PMCID: PMC10844208 DOI: 10.1038/s41598-024-53624-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/02/2024] [Indexed: 02/07/2024] Open
Abstract
Classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV2) are two of the most devastating and economically significant pathogens affecting pig populations worldwide. Administration of a combination of vaccines against swine pathogens has been demonstrated to be as efficacious as the administration of single vaccines. In this study, we developed and tested a novel bivalent subunit vaccine against CSFV and PCV2. The safety and efficacy of this vaccine were demonstrated in mice and specific pathogen-free (SPF) piglets. In addition to investigating the serological responses after immunization, challenge studies with both viruses were also conducted. The results showed that this CSFV/PCV2 bivalent vaccine elicited a high level of neutralizing antibodies against both viruses and provided protection in challenge studies. In conclusion, the CSFV/PCV2 bivalent vaccine is safe and effective against CSFV or PCV2 challenge.
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Affiliation(s)
- Yu-San Chen
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan
| | - Chang-Ye Lee
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan
| | - Chi-Chien Wu
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan
| | - Pei-Lun Kao
- Department of Biotechnology and Animal Science, National Ilan University, Yilan County, Taiwan
| | - Tai-An Chen
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan
| | - Yahui Huang
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan
| | - Wen-Bin Chung
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung County, Taiwan
| | - Tsun-Yung Kuo
- Department of Biotechnology and Animal Science, National Ilan University, Yilan County, Taiwan
| | - Charles Chen
- Schweitzer Biotech Company Ltd, Taipei City, Taiwan.
- Temple University, Philadelphia, PA, 19122, USA.
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Hinojosa Y, Liniger M, García-Nicolás O, Gerber M, Rajaratnam A, Muñoz-González S, Coronado L, Frías MT, Perera CL, Ganges L, Ruggli N. Evolutionary-Related High- and Low-Virulent Classical Swine Fever Virus Isolates Reveal Viral Determinants of Virulence. Viruses 2024; 16:147. [PMID: 38275957 PMCID: PMC10820463 DOI: 10.3390/v16010147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/13/2024] [Accepted: 01/15/2024] [Indexed: 01/27/2024] Open
Abstract
Classical swine fever (CSF) has been eradicated from Western and Central Europe but remains endemic in parts of Central and South America, Asia, and the Caribbean. CSF virus (CSFV) has been endemic in Cuba since 1993, most likely following an escape of the highly virulent Margarita/1958 strain. In recent years, chronic and persistent infections with low-virulent CSFV have been observed. Amino acid substitutions located in immunodominant epitopes of the envelope glycoprotein E2 of the attenuated isolates were attributed to positive selection due to suboptimal vaccination and control. To obtain a complete picture of the mutations involved in attenuation, we applied forward and reverse genetics using the evolutionary-related low-virulent CSFV/Pinar del Rio (CSF1058)/2010 (PdR) and highly virulent Margarita/1958 isolates. Sequence comparison of the two viruses recovered from experimental infections in pigs revealed 40 amino acid differences. Interestingly, the amino acid substitutions clustered in E2 and the NS5A and NS5B proteins. A long poly-uridine sequence was identified previously in the 3' untranslated region (UTR) of PdR. We constructed functional cDNA clones of the PdR and Margarita strains and generated eight recombinant viruses by introducing single or multiple gene fragments from Margarita into the PdR backbone. All chimeric viruses had comparable replication characteristics in porcine monocyte-derived macrophages. Recombinant PdR viruses carrying either E2 or NS5A/NS5B of Margarita, with 36 or 5 uridines in the 3'UTR, remained low virulent in 3-month-old pigs. The combination of these elements recovered the high-virulent Margarita phenotype. These results show that CSFV evolution towards attenuated variants in the field involved mutations in both structural and non-structural proteins and the UTRs, which act synergistically to determine virulence.
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Affiliation(s)
- Yoandry Hinojosa
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, 3012 Bern, Switzerland
- Centro Nacional de Sanidad Agropecuaria (CENSA), San José de las Lajas 32700, Cuba; (M.T.F.); (C.L.P.)
| | - Matthias Liniger
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
| | - Obdulio García-Nicolás
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
| | - Markus Gerber
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
| | - Anojen Rajaratnam
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
| | - Sara Muñoz-González
- WOAH Reference Laboratory for Classical Swine Fever, IRTA-CReSA, 08193 Barcelona, Spain; (S.M.-G.); (L.C.); (L.G.)
- Unitat Mixta d’Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), 08193 Barcelona, Spain
| | - Liani Coronado
- WOAH Reference Laboratory for Classical Swine Fever, IRTA-CReSA, 08193 Barcelona, Spain; (S.M.-G.); (L.C.); (L.G.)
- Unitat Mixta d’Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), 08193 Barcelona, Spain
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), 08193 Barcelona, Spain
| | - María Teresa Frías
- Centro Nacional de Sanidad Agropecuaria (CENSA), San José de las Lajas 32700, Cuba; (M.T.F.); (C.L.P.)
| | - Carmen Laura Perera
- Centro Nacional de Sanidad Agropecuaria (CENSA), San José de las Lajas 32700, Cuba; (M.T.F.); (C.L.P.)
| | - Llilianne Ganges
- WOAH Reference Laboratory for Classical Swine Fever, IRTA-CReSA, 08193 Barcelona, Spain; (S.M.-G.); (L.C.); (L.G.)
- Unitat Mixta d’Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), 08193 Barcelona, Spain
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), 08193 Barcelona, Spain
| | - Nicolas Ruggli
- Division of Virology, Institute of Virology and Immunology IVI, 3147 Mittelhäusern, Switzerland; (Y.H.); (M.L.); (O.G.-N.); (M.G.)
- Department of Infectious Diseases and Pathobiology (DIP), University of Bern, 3012 Bern, Switzerland
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Robert E, Goonewardene K, Lamboo L, Perez O, Goolia M, Lewis C, Erdelyan CNG, Lung O, Handel K, Moffat E, Embury-Hyatt C, Amaya NN, Parra CPC, Rueda DCG, Monroy MAR, Clavijo A, Ambagala A. Molecular and Pathological Characterization of Classical Swine Fever Virus Genotype 2 Strains Responsible for the 2013-2018 Outbreak in Colombia. Viruses 2023; 15:2308. [PMID: 38140549 PMCID: PMC10747092 DOI: 10.3390/v15122308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/07/2023] [Accepted: 11/16/2023] [Indexed: 12/24/2023] Open
Abstract
Classical swine fever (CSF) is a highly contagious transboundary viral disease of domestic and wild pigs. Despite mass vaccination and continuous eradication programs, CSF remains endemic in Asia, some countries in Europe, the Caribbean and South America. Since June 2013, Northern Colombia has reported 137 CSF outbreaks, mostly in backyard production systems with low vaccination coverage. The purpose of this study was to characterize the virus responsible for the outbreak. Phylogenetic analysis based on the full-length E2 sequence shows that the virus is closely related to CSF virus (CSFV) genotype 2.6 strains circulating in Southeast Asia. The pathotyping experiment suggests that the virus responsible is a moderately virulent strain. The 190 nucleotide stretch of the E2 hypervariable region of these isolates also shows high similarity to the CSFV isolates from Colombia in 2005 and 2006, suggesting a common origin for the CSF outbreaks caused by genotype 2.6 strains. The emergence of genotype 2.6 in Colombia suggests a potential transboundary spread of CSFV from Asia to the Americas, complicating the ongoing CSF eradication efforts in the Americas, and emphasizes the need for continuous surveillance in the region.
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Affiliation(s)
- Erin Robert
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Kalhari Goonewardene
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Lindsey Lamboo
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Orlando Perez
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Melissa Goolia
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Charles Lewis
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Cassidy N. G. Erdelyan
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Oliver Lung
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Katherine Handel
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Estella Moffat
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Carissa Embury-Hyatt
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Nancy Naranjo Amaya
- National Veterinary Laboratory, Instituto Colombiano Agropecurio, Bogota 110911, DC, Colombia; (N.N.A.); (C.P.C.P.); (D.C.G.R.); (M.A.R.M.)
| | - Claudia Patricia Calderón Parra
- National Veterinary Laboratory, Instituto Colombiano Agropecurio, Bogota 110911, DC, Colombia; (N.N.A.); (C.P.C.P.); (D.C.G.R.); (M.A.R.M.)
| | - Diana Cristina Gómez Rueda
- National Veterinary Laboratory, Instituto Colombiano Agropecurio, Bogota 110911, DC, Colombia; (N.N.A.); (C.P.C.P.); (D.C.G.R.); (M.A.R.M.)
| | - Maria Antonia Rincón Monroy
- National Veterinary Laboratory, Instituto Colombiano Agropecurio, Bogota 110911, DC, Colombia; (N.N.A.); (C.P.C.P.); (D.C.G.R.); (M.A.R.M.)
| | - Alfonso Clavijo
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
| | - Aruna Ambagala
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3R2, Canada; (E.R.); (K.G.); (L.L.); (O.P.); (M.G.); (C.L.); (C.N.G.E.); (O.L.); (K.H.); (E.M.); (C.E.-H.); (A.C.)
- Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
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Lu X, Ward MP. Spatiotemporal analysis of reported classical swine fever outbreaks in China (2005-2018) and the influence of weather. Transbound Emerg Dis 2022; 69:e3183-e3195. [PMID: 35007396 PMCID: PMC9787383 DOI: 10.1111/tbed.14452] [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: 12/15/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 12/30/2022]
Abstract
Classical swine fever (CSF) is a viral disease that causes enormous economic losses in the swine industry in endemic countries including China. The aims of the current study were to describe the spatial distribution of annual CSF reports in China from 2005 to 2018, identify spatiotemporal clusters of annual CSF reports during this time period and to investigate the correlations between climate factors (rainfall, wind speed, temperature, vapour pressure and relative humidity) and the occurrence of CSF outbreaks. The strongest (Moran's index > 0.19), significant (p < .05) spatial clustering of reported outbreaks was observed during the first 4 years of the study period. This clustering was apparent in the four southern provinces of Guizhou, Guangxi, Guangdong and Yunnan. Five of the six significant (p ≤ .0001) spatiotemporal clusters occurred during the period 2005-2012. These were widely dispersed, with four clusters persisting for only 1 or 2 years, whereas two clusters (Jiangxi and Yunnan) persisted for 8 and 7 years, respectively. As a result of implementation of a national animal disease control plan and increasing coverage of vaccination, CSF outbreaks in China have generally been controlled and reduced, becoming sporadic in most provinces by 2018. We also confirmed that low relative humidity and high wind speed were significant weather variables associated with the occurrence of CSF. Furthermore, our study has confirmed that CSF is still endemic in some Chinese provinces, and we recommend that the national CSF control protocol be updated and standardized.
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Affiliation(s)
- Xiao Lu
- Sydney School of Veterinary ScienceThe University of SydneyCamdenAustralia
| | - Michael P. Ward
- Sydney School of Veterinary ScienceThe University of SydneyCamdenAustralia
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Wu K, Zhang Y, Zeng S, Liu X, Li Y, Li X, Chen W, Li Z, Qin Y, Chen J, Fan S. Development and Application of RAA Nucleic Acid Test Strip Assay and Double RAA Gel Electrophoresis Detection Methods for ASFV and CSFV. Front Mol Biosci 2022; 8:811824. [PMID: 35174210 PMCID: PMC8841470 DOI: 10.3389/fmolb.2021.811824] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
African swine fever (ASF) is an acute, severe and hemorrhagic infectious disease caused by African swine fever virus (ASFV) infecting domestic pigs and wild boars. Since the outbreak of the disease in China in 2018, it has brought a great impact on China’s pig industry. Classical swine fever (CSF) is an acute contact infectious disease of pigs caused by classical swine fever virus (CSFV) infection. Clinically, acute CSF usually shows persistent high fever, anorexia, extensive congestion and bleeding of the skin and mucosa, which are similar to ASF. It is of great significance to prevent, control and accurately detect ASF and CSF in pig farms. In this study, Recombinase aided amplification (RAA) technology combined with a nucleic acid test strip (RAA-strip) was established for simple and specific detection of ASFV/CSFV. The sensitivity and preliminary clinical application results showed that the RAA test strip established in this study could detect recombinant plasmids containing ASFV/CSFV gene fragments as low as 103 copies/µL. The minimum detection limits of virus DNA/cDNA were 10 and 12 pg respectively, and there was no cross-reaction with other porcine viruses. The specificity of the method was good. We used 37–42 clinical samples to evaluate the performance of our established method, and the positive concordance rates with conventional PCR were 94.1 and 57.1%, respectively. In addition, ASFV and CSFV double RAA agarose gel electrophoresis detection methods were established. The results showed that the method had good specificity. The detection limit of this method is 106 copies for ASFV p72 gene recombinant plasmid and 105 copies for CSFV NS5B Gene recombinant plasmid. The use of this method for clinical material detection was consistent with the PCR method. In summary, the developed method of RAA-strip assay for ASFV and CSFV realized the visual detection of pathogens, and the developed method of dual RAA agarose gel electrophoresis assay for ASFV and CSFV realized the simultaneous detection of two pathogens in one reaction, with good specificity, high sensitivity and rapid reaction rate, which was expected to be clinically feasible for the differential diagnosis of ASF and CSF provided technical support.
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Affiliation(s)
- Keke Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Yuanyuan Zhang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Sen Zeng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Xiaodi Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Yuwan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Xiaowen Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Wenxian Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Zhaoyao Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yuwei Qin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- *Correspondence: Jinding Chen, ; Shuangqi Fan,
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- *Correspondence: Jinding Chen, ; Shuangqi Fan,
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Genetic diversity and molecular characterization of classical swine fever virus envelope protein genes E2 and E rns circulating in Vietnam from 2017 to 2019. INFECTION GENETICS AND EVOLUTION 2021; 96:105140. [PMID: 34781037 DOI: 10.1016/j.meegid.2021.105140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 11/01/2021] [Accepted: 11/09/2021] [Indexed: 11/22/2022]
Abstract
Classical swine fever virus (CSFV) is an RNA virus that incurs severe economic costs to swine industries worldwide. This study was conducted to investigate the genetic diversity among CSFV strains circulating in Vietnam, with a focus on their genetic variants relative to four vaccine strains. Samples from clinical cases were collected from different provinces of Central and Southern Vietnam from 2017 to 2019. 21 CSFV-positive samples were selected for amplification and sequencing of the full-length Erns and E2 genes. Phylogenetic analyses of these two genes showed that most CSFV strains circulating in Central and Southern Vietnam from 2017 to 2019 belong to subgroup 2.1c, whereas the remaining strains cluster into subgroup 2.2. All CSFV field strains in this study were genetically distant from group 1 strains. Analysis of the E2 and Erns genes indicated that all CSFV field strains have low sequence identity with the vaccine strains (80-83.5% and 82.3-86% sequence identity for E2 and Erns, respectively). Likewise, amino acid-level sequence analysis showed 87.3-91.1% and 87.6-91.6% sequence identity for E2 and Erns, respectively. Together, our findings indicate that CSFV strains circulating in Vietnam belong to subtypes 2.2 and 2.1c, and we also provide novel insights into the epidemiology, molecular characteristics, genetic diversity, and evolution of these circulating CSFV strains.
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Zhu X, Liu M, Wu X, Ma W, Zhao X. Phylogenetic analysis of classical swine fever virus isolates from China. Arch Virol 2021; 166:2255-2261. [PMID: 34003359 DOI: 10.1007/s00705-021-05084-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 03/18/2021] [Indexed: 11/26/2022]
Abstract
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a severe disease that causes huge economic losses in the swine industry worldwide. In China, CSF has been under control due to extensive vaccination since 1954. However, there are still sporadic CSF outbreaks in China. Here, we isolated 27 CSFV strains from three Chinese provinces (Shaanxi, Gansu, and Ningxia) from 2011 to 2018. Phylogenetic analysis based on the full-length envelope glycoprotein E2 coding region revealed that 25 out of 27 CSFV isolates clustered within subgroups 2.1 and 2.2, while two strains from Gansu belonged to subgroup 1.1. The sequence identity among these 27 isolates varied from 79.3% to 99.8% (nucleotides) and from 83.1% to 99.7% (amino acids). Further analysis based on the E2 amino acid sequences showed that these new isolates have consistent amino acid substitutions, including R31K and N34S.
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Affiliation(s)
- Xiaofu Zhu
- Key Laboratory of Animal Epidemic Disease Diagnostic Laboratory of Molecular Biology in Xianyang City, Xianyang Vocational Technical College, Xianyang, 712000, Shaanxi, China.
| | - Mingjie Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xujin Wu
- Key Laboratory of Animal Epidemic Disease Diagnostic Laboratory of Molecular Biology in Xianyang City, Xianyang Vocational Technical College, Xianyang, 712000, Shaanxi, China
| | - Wentao Ma
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xuanduo Zhao
- Yangling Bodeyue Biotechnology Co., Ltd., Yangling, 712100, Shaanxi, China
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Lee HS, Bui VN, Dao DT, Bui NA, Le TD, Kieu MA, Nguyen QH, Tran LH, Roh JH, So KM, Hur TY, Oh SI. Pathogenicity of an African swine fever virus strain isolated in Vietnam and alternative diagnostic specimens for early detection of viral infection. Porcine Health Manag 2021; 7:36. [PMID: 33934707 PMCID: PMC8091783 DOI: 10.1186/s40813-021-00215-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Background African swine fever (ASF), caused by the ASF virus (ASFV), was first reported in Vietnam in 2019 and spread rapidly thereafter. Better insights into ASFV characteristics and early detection by surveillance could help control its spread. However, the pathogenicity and methods for early detection of ASFV isolates from Vietnam have not been established. Therefore, we investigated the pathogenicity of ASFV and explored alternative sampling methods for early detection. Results Ten pigs were intramuscularly inoculated with an ASFV strain from Vietnam (titer, 103.5 HAD50/mL), and their temperature, clinical signs, and virus excretion patterns were recorded. In addition, herd and environmental samples were collected daily. The pigs died 5–8 days-post-inoculation (dpi), and the incubation period was 3.7 ± 0.5 dpi. ASFV genome was first detected in the blood (2.2 ± 0.8) and then in rectal (3.1 ± 0.7), nasal (3.2 ± 0.4), and oral (3.6 ± 0.7 dpi) swab samples. ASFV was detected in oral fluid samples collected using a chewed rope from 3 dpi. The liver showed the highest viral loads, and ear tissue also exhibited high viral loads among 11 tissues obtained from dead pigs. Overall, ASFV from Vietnam was classified as peracute to acute form. The rope-based oral fluid collection method could be useful for early ASFV detection and allows successful ASF surveillance in large pig farms. Furthermore, ear tissue samples might be a simple alternative specimen for diagnosing ASF infection in dead pigs. Conclusions Our data provide valuable insights into the characteristics of a typical ASFV strain isolated in Vietnam and suggest an alternative, non-invasive specimen collection strategy for early detection.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Hanoi, Vietnam
| | - Vuong Nghia Bui
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Duy Tung Dao
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Ngoc Anh Bui
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Thanh Duy Le
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Minh Anh Kieu
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Quang Huy Nguyen
- International Livestock Research Institute (ILRI), Hanoi, Vietnam.,Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Long Hoang Tran
- Virology Department, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi, Vietnam
| | - Jae-Hee Roh
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Kyoung-Min So
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Tai-Young Hur
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea
| | - Sang-Ik Oh
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, 55365, Wanju, Republic of Korea.
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9
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Fan J, Liao Y, Zhang M, Liu C, Li Z, Li Y, Li X, Wu K, Yi L, Ding H, Zhao M, Fan S, Chen J. Anti-Classical Swine Fever Virus Strategies. Microorganisms 2021; 9:microorganisms9040761. [PMID: 33917361 PMCID: PMC8067343 DOI: 10.3390/microorganisms9040761] [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: 03/02/2021] [Revised: 03/24/2021] [Accepted: 04/02/2021] [Indexed: 12/23/2022] Open
Abstract
Classical swine fever (CSF), caused by CSF virus (CSFV), is a highly contagious swine disease with high morbidity and mortality, which has caused significant economic losses to the pig industry worldwide. Biosecurity measures and vaccination are the main methods for prevention and control of CSF since no specific drug is available for the effective treatment of CSF. Although a series of biosecurity and vaccination strategies have been developed to curb the outbreak events, it is still difficult to eliminate CSF in CSF-endemic and re-emerging areas. Thus, in addition to implementing enhanced biosecurity measures and exploring more effective CSF vaccines, other strategies are also needed for effectively controlling CSF. Currently, more and more research about anti-CSFV strategies was carried out by scientists, because of the great prospects and value of anti-CSFV strategies in the prevention and control of CSF. Additionally, studies on anti-CSFV strategies could be used as a reference for other viruses in the Flaviviridae family, such as hepatitis C virus, dengue virus, and Zika virus. In this review, we aim to summarize the research on anti-CSFV strategies. In detail, host proteins affecting CSFV replication, drug candidates with anti-CSFV effects, and RNA interference (RNAi) targeting CSFV viral genes were mentioned and the possible mechanisms related to anti-CSFV effects were also summarized.
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Affiliation(s)
- Jindai Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Yingxin Liao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Mengru Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Chenchen Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Zhaoyao Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Yuwan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Xiaowen Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Keke Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Lin Yi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Hongxing Ding
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
- Correspondence: (S.F.); (J.C.); Tel.: +86-20-8528-8017 (J.C.)
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (J.F.); (Y.L.); (M.Z.); (C.L.); (Z.L.); (Y.L.); (X.L.); (K.W.); (L.Y.); (H.D.); (M.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
- Correspondence: (S.F.); (J.C.); Tel.: +86-20-8528-8017 (J.C.)
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10
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Coronado L, Perera CL, Rios L, Frías MT, Pérez LJ. A Critical Review about Different Vaccines against Classical Swine Fever Virus and Their Repercussions in Endemic Regions. Vaccines (Basel) 2021; 9:154. [PMID: 33671909 PMCID: PMC7918945 DOI: 10.3390/vaccines9020154] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/31/2021] [Accepted: 02/09/2021] [Indexed: 12/24/2022] Open
Abstract
Classical swine fever (CSF) is, without any doubt, one of the most devasting viral infectious diseases affecting the members of Suidae family, which causes a severe impact on the global economy. The reemergence of CSF virus (CSFV) in several countries in America, Asia, and sporadic outbreaks in Europe, sheds light about the serious concern that a potential global reemergence of this disease represents. The negative aspects related with the application of mass stamping out policies, including elevated costs and ethical issues, point out vaccination as the main control measure against future outbreaks. Hence, it is imperative for the scientific community to continue with the active investigations for more effective vaccines against CSFV. The current review pursues to gather all the available information about the vaccines in use or under developing stages against CSFV. From the perspective concerning the evolutionary viral process, this review also discusses the current problematic in CSF-endemic countries.
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Affiliation(s)
- Liani Coronado
- National Centre for Animal and Plant Health (CENSA), OIE Collaborating Centre for Disaster Risk Reduction in Animal Health, San José de las Lajas 32700, Cuba; (L.C.); (C.L.P.); (M.T.F.)
| | - Carmen L. Perera
- National Centre for Animal and Plant Health (CENSA), OIE Collaborating Centre for Disaster Risk Reduction in Animal Health, San José de las Lajas 32700, Cuba; (L.C.); (C.L.P.); (M.T.F.)
| | - Liliam Rios
- Reiman Cancer Research Laboratory, Faculty of Medicine, University of New Brunswick, Saint John, NB E2L 4L5, Canada;
| | - María T. Frías
- National Centre for Animal and Plant Health (CENSA), OIE Collaborating Centre for Disaster Risk Reduction in Animal Health, San José de las Lajas 32700, Cuba; (L.C.); (C.L.P.); (M.T.F.)
| | - Lester J. Pérez
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois at Urbana–Champaign, Champaign, IL 61802, USA
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11
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Hao G, Zhang H, Chen H, Qian P, Li X. Comparison of the Pathogenicity of Classical Swine Fever Virus Subgenotype 2.1c and 2.1d Strains from China. Pathogens 2020; 9:pathogens9100821. [PMID: 33036431 PMCID: PMC7600237 DOI: 10.3390/pathogens9100821] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 12/16/2022] Open
Abstract
Classical swine fever (CSF) caused by classical swine fever virus (CSFV) is a highly contagious and devastating disease. The traditional live attenuated C-strain vaccine is widely used to control disease outbreaks in China. Since 2000, subgenotype 2.1 has become dominant in China. Here, we isolated subgenotype 2.1c and 2.1d strains from CSF-suspected pigs. The genetic variations and pathogenesis of subgenotype 2.1c and 2.1d strains were investigated experimentally. We aimed to evaluate and compare the replication characteristics and clinical signs of subgenotype 2.1c and 2.1d strains with those of the typical highly virulent CSFV SM strain. In PK-15 cells, the three CSFV isolates exhibited similar replication levels but significantly lower replication levels compared with the CSFV SM strain. The experimental animal infection model showed that the pathogenicity of subgenotype 2.1c and 2.1d strains was less than that of the CSFV SM strain. According to the clinical scoring system, subgenotype 2.1c (GDGZ-2019) and 2.1d (HBXY-2019 and GXGG-2019) strains were moderately virulent. This study showed that the pathogenicity of CSFV field strains will aid in the understanding of CSFV biological characteristics and the related epidemiology.
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Affiliation(s)
- Genxi Hao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (G.H.); (H.Z.); (H.C.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Huawei Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (G.H.); (H.Z.); (H.C.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (G.H.); (H.Z.); (H.C.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Ping Qian
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (G.H.); (H.Z.); (H.C.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Correspondence: (P.Q.); (X.L.); Tel.: +86-27-87282608 (P.Q.)
| | - Xiangmin Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (G.H.); (H.Z.); (H.C.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Correspondence: (P.Q.); (X.L.); Tel.: +86-27-87282608 (P.Q.)
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12
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Izzati UZ, Inanaga M, Hoa NT, Nueangphuet P, Myint O, Truong QL, Lan NT, Norimine J, Hirai T, Yamaguchi R. Pathological investigation and viral antigen distribution of emerging African swine fever in Vietnam. Transbound Emerg Dis 2020; 68:2039-2050. [PMID: 32979250 PMCID: PMC8359366 DOI: 10.1111/tbed.13851] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/29/2020] [Accepted: 09/18/2020] [Indexed: 11/30/2022]
Abstract
African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the May to July 2019 outbreak of ASF was performed to determine the characteristic lesions. We analysed samples from eight ASFV‐infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
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Affiliation(s)
- Uda Zahli Izzati
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Minori Inanaga
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Nguyen Thi Hoa
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Phawut Nueangphuet
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Ohnmar Myint
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Quang Lam Truong
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Nguyen Thi Lan
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Junzo Norimine
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Takuya Hirai
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
| | - Ryoji Yamaguchi
- Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan
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13
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Atypical Porcine Pestivirus Circulation and Molecular Evolution within an Affected Swine Herd. Viruses 2020; 12:v12101080. [PMID: 32992946 PMCID: PMC7599615 DOI: 10.3390/v12101080] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 01/27/2023] Open
Abstract
Atypical porcine pestivirus (APPV) is a single-stranded RNA virus from the family Flaviviridae, which is linked to congenital tremor (CT) type A-II in newborn piglets. Here, we retrospectively investigated the molecular evolution of APPV on an affected herd between 2013 and 2019. Monitoring was done at regular intervals, and the same genotype of APPV was found during the entire study period, suggesting no introductions from outside the farm. The nucleotide substitutions over time did not show substantial amino acid variation in the structural glycoproteins. Furthermore, the evolution of the virus showed mainly purifying selection, and no positive selection. The limited pressure on the virus to change at immune-dominant regions suggested that the immune pressure at the farm might be low. In conclusion, farms can have circulation of APPV for years, and massive testing and removal of infected animals are not sufficient to clear the virus from affected farms.
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14
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Classical Swine Fever: A Truly Classical Swine Disease. Pathogens 2020; 9:pathogens9090745. [PMID: 32927731 PMCID: PMC7560091 DOI: 10.3390/pathogens9090745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/09/2020] [Accepted: 09/09/2020] [Indexed: 11/26/2022] Open
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15
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Li YC, Chiou MT, Lin CN. Serodynamic Analysis of the Piglets Born from Sows Vaccinated with Modified Live Vaccine or E2 Subunit Vaccine for Classical Swine Fever. Pathogens 2020; 9:pathogens9060427. [PMID: 32485982 PMCID: PMC7350299 DOI: 10.3390/pathogens9060427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/23/2020] [Accepted: 05/27/2020] [Indexed: 02/03/2023] Open
Abstract
Classical swine fever (CSF) caused by the CSF virus (CSFV) is one of the most important swine diseases, resulting in huge economic losses to the pig industry worldwide. Systematic vaccination is one of the most effective strategies for the prevention and control of this disease. Two main CSFV vaccines, the modified live vaccine (MLV) and the subunit E2 vaccine, are recommended. In Taiwan, CSF cases have not been reported since 2006, although systemic vaccination has been practiced for 70 years. Here, we examined the sero-dynamics of the piglets born from sows that received either the CSFV MLV or the E2 vaccine and investigated in the field the correlation between the porcine reproductive and respiratory syndrome virus (PRRSV) loads and levels of CSFV antibody. A total of 1398 serum samples from 42 PRRSV-positive farms were evaluated to determine the PRRSV loads by real-time PCR and to detect CSFV antibody levels by commercial ELISA. Upon comparing the two sow vaccination protocols (CSFV MLV vaccination at 4 weeks post-farrowing versus E2 vaccination at 4-5 weeks pre-farrowing), the lowest levels of CSFV antibody were found in piglets at 5-8 and 9-12 weeks of age for the MLV and E2 groups, respectively. Meanwhile, the appropriate time window for CSFV vaccination of offspring was at 5-8 and 9-12 weeks of age in the MLV and E2 groups, respectively. There was a very highly significant negative correlation between the PRRSV load and the level of CSFV antibody in the CSFV MLV vaccination group (P < 0.0001). The PRRSV detection rate in the pigs from the MLV group (27.78%) was significantly higher than that in pigs from the E2 group (21.32%) (P = 0.011). In addition, there was a significant difference (P = 0.019) in the PRRSV detection rate at 5-8 weeks of age between the MLV (42.15%) and E2 groups (29.79%). Our findings indicate that the vaccination of CSFV MLV in piglets during the PRRSV susceptibility period at 5-8 weeks of age may be overloading the piglet's immune system and should be a critical concern for industrial pork production in the field.
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Affiliation(s)
- Yi-Chia Li
- Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Ming-Tang Chiou
- Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: (M.-T.C.); (C.-N.L.); Tel.: +886-8-7703202-5057 (M.-T.C.); +886-8-7703202-5047 (C.-N.L.)
| | - Chao-Nan Lin
- Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: (M.-T.C.); (C.-N.L.); Tel.: +886-8-7703202-5057 (M.-T.C.); +886-8-7703202-5047 (C.-N.L.)
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