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Zhong D, Lu Z, Xia Y, Wu H, Zhang X, Li M, Song X, Wang Y, Moon A, Qiu HJ, Li Y, Sun Y. Ferritin Nanoparticle Delivery of the E2 Protein of Classical Swine Fever Virus Completely Protects Pigs from Lethal Challenge. Vaccines (Basel) 2024; 12:629. [PMID: 38932358 PMCID: PMC11209039 DOI: 10.3390/vaccines12060629] [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: 04/29/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
Classical swine fever (CSF), caused by the classical swine fever virus (CSFV), results in significant economic losses to the swine industry in many countries. Vaccination represents the primary strategy to control CSF and the CSFV E2 protein is known as the major protective antigen. However, the E2 protein expressed or presented by different systems elicits distinct immune responses. In this study, we established a stable CHO cell line to express the E2 protein and delivered it using self-assembled ferritin nanoparticles (NPs). Subsequently, we compared the adaptive immune responses induced by the E2-ferritin NPs and the monomeric E2 protein produced by the CHO cells or a baculovirus expression system. The results revealed that the NP-delivered E2 protein elicited higher titers of neutralizing antibodies than did the monomeric E2 protein in pigs. Importantly, only the NP-delivered E2 protein significantly induced CSFV-specific IFN-γ-secreting cells. Furthermore, all the pigs inoculated with the E2-ferritin NPs were completely protected from a lethal CSFV challenge infection. These findings demonstrate the ability of the E2-ferritin NPs to protect pigs against the lethal CSFV challenge by eliciting robust humoral and cellular immune responses.
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Affiliation(s)
- Dailang Zhong
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Zhanhao Lu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Yu Xia
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
- School of Animal Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Hongxia Wu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Xinyu Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Mingzhi Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
- School of Animal Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Xin Song
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Yanjin Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Assad Moon
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Hua-Ji Qiu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Yongfeng Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
| | - Yuan Sun
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (D.Z.); (Z.L.); (Y.X.); (H.W.); (X.Z.); (M.L.); (X.S.); (Y.W.); (A.M.); (H.-J.Q.)
- School of Animal Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
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Zhang H, Li C, Xu H, Gong B, Li W, Guo Z, Xiang L, Sun Q, Zhao J, Peng J, Wang Q, Zhou G, Tang YD, An T, Cai XH, Tian ZJ. Protective efficacy of a candidate live attenuated vaccine derived from the SD-R strain of lineage 1 porcine reproductive and respiratory syndrome virus against a lethal challenge with HP-PRRSV HuN4 in piglets. Microbiol Spectr 2023; 11:e0198423. [PMID: 37819126 PMCID: PMC10714764 DOI: 10.1128/spectrum.01984-23] [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: 05/13/2023] [Accepted: 08/19/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Both highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) and NADC30-like PRRSV have caused tremendous economic losses to the Chinese pig industry. In this study, a good challenge model was established to evaluate the protection afforded by the candidate SD-R vaccine against infection with a representative HP-PRRSV strain (HuN4). The control piglets in the challenge experiment displayed obvious clinical symptoms of PRRSV infection, with a mortality rate up to 40%. In contrast, all the piglets in the vaccinated challenged group survived, and only some pigs had transient fever. The daily gain of SD-R immunized group piglets was significantly increased, and the pathological changes were significantly reduced. In addition, the viral replication levels in the serum of the immunized group were significantly lower than those of the challenged control group. The live attenuated vaccine SD-R strain can provide protection against HP-PRRSV challenge, indicating that the SD-R strain is a promising vaccine candidate for use in the swine industry.
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Affiliation(s)
- Hongliang Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chao Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Hu Xu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Bangjun Gong
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Wansheng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhenyang Guo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Lirun Xiang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qi Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jing Zhao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jinmei Peng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qian Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guohui Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yan-Dong Tang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Tongqing An
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xue-Hui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhi-Jun Tian
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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Singh N, Batra K, Chaudhary D, Punia M, Kumar A, Maan NS, Maan S. Prevalence of porcine viral respiratory diseases in India. Anim Biotechnol 2023; 34:1642-1654. [PMID: 35112631 DOI: 10.1080/10495398.2022.2032117] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The pig industry is growing rapidly in India and contributes a major share of growth in the livestock sector. Over the last few years, there is a gradual increase in the adoption of pigs for production by economically weaker sections of the country. However, this production is affected by many respiratory diseases which are responsible for significant economic loss. The occurrence and impact of these diseases are still under-documented. The four important pathogens including porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza A viruses (SIV) and classical swine fever virus (CSFV) are documented here. These diseases are highly devastating in nature and frequent outbreaks have been reported from different parts of the country. The rapid and specific diagnosis, effective prevention and control measures are required for the eradication of these diseases which is urgently required for the growth of the pig industry. This review highlights the prevalence, epidemiology, diagnostics and information gaps on important respiratory viral pathogens of pigs reported from different parts of India. This review also emphasizes the importance of these viral diseases and the urgent need to develop vaccines and effective measures for the eradication of these diseases.
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Affiliation(s)
- Neha Singh
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
| | - Kanisht Batra
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
| | - Deepika Chaudhary
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
| | - Monika Punia
- Department of Biotechnology, Ch. Devi Lal University, Sirsa, India
| | - Aman Kumar
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
| | - Narender Singh Maan
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
| | - Sushila Maan
- College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Science (LUVAS), Hisar, India
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Chen WT, Liu HM, Chang CY, Deng MC, Huang YL, Chang YC, Chang HW. Cross-reactivities and cross-neutralization of different envelope glycoproteins E2 antibodies against different genotypes of classical swine fever virus. Front Vet Sci 2023; 10:1169766. [PMID: 37180072 PMCID: PMC10172653 DOI: 10.3389/fvets.2023.1169766] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/10/2023] [Indexed: 05/15/2023] Open
Abstract
Classical swine fever (CSF) is a highly contagious swine disease caused by the classical swine fever virus (CSFV), wreaking havoc on global swine production. The virus is divided into three genotypes, each comprising 4-7 sub-genotypes. The major envelope glycoprotein E2 of CSFV plays an essential role in cell attachment, eliciting immune responses, and vaccine development. In this study, to study the cross-reaction and cross-neutralizing activities of antibodies against different genotypes (G) of E2 glycoproteins, ectodomains of G1.1, G2.1, G2.1d, and G3.4 CSFV E2 glycoproteins from a mammalian cell expression system were generated. The cross-reactivities of a panel of immunofluorescence assay-characterized serum derived from pigs with/without a commercial live attenuated G1.1 vaccination against different genotypes of E2 glycoproteins were detected by ELISA. Our result showed that serum against the LPCV cross-reacted with all genotypes of E2 glycoproteins. To evaluate cross-neutralizing activities, hyperimmune serum from different CSFV E2 glycoprotein-immunized mice was also generated. The result showed that mice anti-E2 hyperimmune serum exhibited better neutralizing abilities against homologous CSFV than heterogeneous viruses. In conclusion, the results provide information on the cross-reactivity of antibodies against different genogroups of CSFV E2 glycoproteins and suggest the importance of developing multi-covalent subunit vaccines for the complete protection of CSF.
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Affiliation(s)
- Wei-Tao Chen
- School of Veterinary Medicine National Taiwan University, Taipei, Taiwan
- School of Veterinary Medicine, Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan
| | - Hsin-Meng Liu
- School of Veterinary Medicine National Taiwan University, Taipei, Taiwan
- School of Veterinary Medicine, Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan
- College of Bioresources and Agriculture, Animal Health Research Institute, Tamsui, Taiwan
| | - Chia-Yi Chang
- School of Veterinary Medicine National Taiwan University, Taipei, Taiwan
| | - Ming-Chung Deng
- College of Bioresources and Agriculture, Animal Health Research Institute, Tamsui, Taiwan
| | - Yu-Liang Huang
- College of Bioresources and Agriculture, Animal Health Research Institute, Tamsui, Taiwan
| | - Yen-Chen Chang
- School of Veterinary Medicine National Taiwan University, Taipei, Taiwan
- School of Veterinary Medicine, Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan
| | - Hui-Wen Chang
- School of Veterinary Medicine National Taiwan University, Taipei, Taiwan
- School of Veterinary Medicine, Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan
- *Correspondence: Hui-Wen Chang,
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Liu Y, Bahoussi AN, Wang PH, Wu C, Xing L. Complete genome sequences of classical swine fever virus: Phylogenetic and evolutionary analyses. Front Microbiol 2022; 13:1021734. [PMID: 36225377 PMCID: PMC9549409 DOI: 10.3389/fmicb.2022.1021734] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 09/02/2022] [Indexed: 11/21/2022] Open
Abstract
The classical swine fever virus (CSFV) outbreaks cause colossal losses of pigs and drastic economic impacts. The current phylogenetic CSFV groups were determined mainly based on the partial genome. Herein, 203 complete genomic sequences of CSFVs collected worldwide between 1998 and 2018 available on the GenBank database were retrieved for re-genotyping and recombination analysis. The maximum likelihood phylogenetic tree determined two main groups, GI and GII, with multiple sub-genotypes. The “strain 39” (GenBank ID: AF407339), previously identified as belonging to sub-genotypes 1.1 or 2.2 based on the partial sequences, is found to be genetically distinct and independent, forming a new lineage depicted as GI-2.2b. Ten potential natural recombination events were identified, seven of which were collected in China and found involved in the genetic diversity of CSFVs. Importantly, the vaccine strains and highly virulent strains were all involved in the recombination events, which would induce extra challenges to vaccine development. These findings alarm that attenuated vaccines should be applied with discretion and recommend using subunit vaccines in parallel with other preventive strategies for better management of CSFVs.
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Affiliation(s)
- Yue Liu
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, China
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Shanxi University, Taiyuan, China
- Shanxi Provincial Key Laboratory for Prevention and Treatment of Major Infectious Diseases, Taiyuan, China
| | | | - Pei-Hua Wang
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, China
| | - Changxin Wu
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, China
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Shanxi University, Taiyuan, China
- Shanxi Provincial Key Laboratory for Prevention and Treatment of Major Infectious Diseases, Taiyuan, China
| | - Li Xing
- Institute of Biomedical Sciences, Shanxi University, Taiyuan, China
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Shanxi University, Taiyuan, China
- Shanxi Provincial Key Laboratory for Prevention and Treatment of Major Infectious Diseases, Taiyuan, China
- *Correspondence: Li Xing
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Yao J, Su L, Wang Q, Gao L, Xie J, He Y, Shu X, Song C, Chai J, Zhang Y, Yang S. Epidemiological investigation and phylogenetic analysis of Classical Swine Fever virus in Yunnan province from 2015 to 2021. J Vet Sci 2022; 23:e57. [PMID: 35920121 PMCID: PMC9346530 DOI: 10.4142/jvs.22042] [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: 02/15/2022] [Revised: 05/06/2022] [Accepted: 05/13/2022] [Indexed: 11/20/2022] Open
Abstract
Background Classical swine fever virus (CSFV), the causative agent of classical swine fever (CFS), is a highly contagious disease that poses a serious threat to Chinese pig populations. Objectives Many provinces of China, such as Shandong, Henan, Hebei, Heilongjiang, and Liaoning provinces, have reported epidemics of CSFV, while the references to the epidemic of CSFV in Yunnan province are rare. This study examined the epidemic characteristics of the CSFV in Yunnan province. Methods In this study, 326 tissue samples were collected from different regions in Yunnan province from 2015 to 2021. A reverse transcription-polymerase chain reaction (RT-PCR), sequences analysis, and phylogenetic analysis were performed for the pathogenic detection and analysis of these 326 clinical specimens. Results Approximately 3.37% (11/326) of specimens tested positive for the CSFV by RT-PCR, which is lower than that of other regions of China. Sequence analysis of the partial E2 sequences of eleven CSFV strains showed that they shared 89.0–100.0% nucleotide (nt) and 95.0–100.0% amino acid (aa) homology, respectively. Phylogenetic analysis showed that these novel isolates belonged to the subgenotypes 2.1c and 2.1d, with subgenotype 2.1c being predominant. Conclusions The CSFV was sporadic in China’s Yunnan province from 2015 to 2021. Both 2.1c and 2.1d subgenotypes were found in this region, but 2.1c was dominant.
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Affiliation(s)
- Jun Yao
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science & Veterinary Institute, Kunming 650224, China
| | - Linlin Su
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Qiaoping Wang
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Lin Gao
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science & Veterinary Institute, Kunming 650224, China
| | - Jiarui Xie
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science & Veterinary Institute, Kunming 650224, China
| | - Yuwen He
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science & Veterinary Institute, Kunming 650224, China
| | - Xianghua Shu
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Chunlian Song
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Jun Chai
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Yifang Zhang
- College of Animal Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Shibiao Yang
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science & Veterinary Institute, Kunming 650224, China
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Oki M, Ikezawa M, Nishi T, Fukai K, Yamada M. Immunohistochemical analysis of the distribution of classical swine fever (CSF) viral antigen in boar-pig hybrids and pigs four weeks after infection. J Vet Med Sci 2021; 84:48-52. [PMID: 34789589 PMCID: PMC8810325 DOI: 10.1292/jvms.21-0226] [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] [Indexed: 11/22/2022] Open
Abstract
We detected the classical swine fever virus (CSFV) antigen in three boar-pig hybrids (hybrids) and three pigs. All animals were experimentally infected with CSFV strain JPN/27/2019 to optimize diagnostic sampling and risk assessment of virus dissemination. Two hybrids died 17- and 19-days post-inoculation (dpi). The other animals were euthanized at 28 dpi. The detection of CSFV antigen at 28 dpi in epithelial cells of the apocrine sweat and sebaceous glands in the skin, salivary glands, mucosal epithelial cells in the rectum, and epithelial cells in the kidney and urinary bladder, suggests that CSFV persists in these tissues and spreads via sweat, saliva, feces, and urine for at least 4 weeks. These findings reveal that hybrids and pigs represent a high risk of virus dissemination four weeks after infection with CSFV strain JPN/27/2019. Prominent CSFV antigens were also detected in hair follicles of the skin. These results suggest that postmortem sampling of animal skin may be effective for CSF diagnosis and can be used to develop a rapid and easy diagnostic method using hair follicles.
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Affiliation(s)
| | - Mitsutaka Ikezawa
- National Institute of Animal Health, National Agriculture and Food Research Organization
| | - Tatsuya Nishi
- National Institute of Animal Health, National Agriculture and Food Research Organization
| | - Katsuhiko Fukai
- National Institute of Animal Health, National Agriculture and Food Research Organization
| | - Manabu Yamada
- National Institute of Animal Health, National Agriculture and Food Research Organization
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Patil SS, Indrabalan UB, Suresh KP, Shome BR. Analysis of codon usage bias of classical swine fever virus. Vet World 2021; 14:1450-1458. [PMID: 34316191 PMCID: PMC8304411 DOI: 10.14202/vetworld.2021.1450-1458] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/21/2021] [Indexed: 11/22/2022] Open
Abstract
Background and Aim: Classical swine fever (CSF), caused by CSF virus (CSFV), is a highly contagious disease in pigs causing 100% mortality in susceptible adult pigs and piglets. High mortality rate in pigs causes huge economic loss to pig farmers. CSFV has a positive-sense RNA genome of 12.3 kb in length flanked by untranslated regions at 5’ and 3’ end. The genome codes for a large polyprotein of 3900 amino acids coding for 11 viral proteins. The 1300 codons in the polyprotein are coded by different combinations of three nucleotides which help the infectious agent to evolve itself and adapt to the host environment. This study performed and employed various methods/techniques to estimate the changes occurring in the process of CSFV evolution by analyzing the codon usage pattern. Materials and Methods: The evolution of viruses is widely studied by analyzing their nucleotides and coding regions/codons using various methods. A total of 115 complete coding regions of CSFVs including one complete genome from our laboratory (MH734359) were included in this study and analysis was carried out using various methods in estimating codon usage bias and evolution. This study elaborates on the factors that influence the codon usage pattern. Results: The effective number of codons (ENC) and relative synonymous codon usage showed the presence of codon usage bias. The mononucleotide (A) has a higher frequency compared to the other mononucleotides (G, C, and T). The dinucleotides CG and CC are underrepresented and overrepresented. The codons CGT was underrepresented and AGG was overrepresented. The codon adaptation index value of 0.71 was obtained indicating that there is a similarity in the codon usage bias. The principal component analysis, ENC-plot, Neutrality plot, and Parity Rule 2 plot produced in this article indicate that the CSFV is influenced by the codon usage bias. The mutational pressure and natural selection are the important factors that influence the codon usage bias. Conclusion: The study provides useful information on the codon usage analysis of CSFV and may be utilized to understand the host adaptation to virus environment and its evolution. Further, such findings help in new gene discovery, design of primers/probes, design of transgenes, determination of the origin of species, prediction of gene expression level, and gene function of CSFV. To the best of our knowledge, this is the first study on codon usage bias involving such a large number of complete CSFVs including one sequence of CSFV from India.
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Affiliation(s)
- Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Yelahanka, Bengaluru, Karnataka, India
| | - Uma Bharathi Indrabalan
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Yelahanka, Bengaluru, Karnataka, India
| | | | - Bibek Ranjan Shome
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Yelahanka, Bengaluru, Karnataka, India
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Genotyping and Molecular Characterization of Classical Swine Fever Virus Isolated in China during 2016-2018. Viruses 2021; 13:v13040664. [PMID: 33921513 PMCID: PMC8069065 DOI: 10.3390/v13040664] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/17/2022] Open
Abstract
Classical swine fever (CSF) is a highly contagious disease of swine caused by classical swine fever virus (CSFV). For decades the disease has been controlled in China by a modified live vaccine (C-strain) of genotype 1. The emergent genotype 2 strains have become predominant in China in the past years that are genetically distant from the vaccine strain. Here, we aimed to evaluate the current infectious status of CSF, and for this purpose 24 isolates of CSFV were identified from different areas of China during 2016–2018. Phylogenetic analysis of NS5B, E2 and full genome revealed that the new isolates were clustered into subgenotype 2.1d and 2.1b, while subgenotype 2.1d was predominant. Moreover, E2 and Erns displayed multiple variations in neutralizing epitope regions. Furthermore, the new isolates exhibited capacity to escape C-strain-derived antibody neutralization compared with the Shimen strain (genotype 1). Potential positive selection sites were identified in antigenic regions of E2 and Erns, which are related with antibody binding affinity. Recombination events were predicted in the new isolates with vaccine strains in the E2 gene region. In conclusion, the new isolates showed molecular variations and antigenic alterations, which provide evidence for the emergence of vaccine-escaping mutants and emphasize the need of updated strategies for CSF control.
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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: 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: 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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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: 29] [Impact Index Per Article: 9.7] [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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Wang Q, Liu H, Xu L, Li J, Wu H, Yang C, Chen X, Deng Y, Sun Y, Tu C, Chen N, Gong W, Chen G. Different clinical presentations of subgenotype 2.1 strain of classical swine fever infection in weaned piglets and adults, and long-term cross-protection conferred by a C-strain vaccine. Vet Microbiol 2020; 253:108915. [PMID: 33309157 DOI: 10.1016/j.vetmic.2020.108915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022]
Abstract
Classical swine fever is an important swine disease in China, and sporadic outbreaks with mild clinical signs despite compulsory vaccination have raised questions about the virulence and pathogenicity of prevalent subgenotype 2.1 strains, and the ability of C-strain vaccines to cross-protect against them. To investigate this, three field isolates were evaluated in experimentally infected piglets and compared with the highly virulent reference Shimen strain. Clinical signs for the field strains ranged from mild to severe, and mortality ranged from 0 to 80 %. These data show differences in virulence among the subgenotype 2.1 field isolates and support the use of field strain GD191 as a genotype 2 challenge virus to assess efficacy of C-strain vaccines. In contrast to the historical genotype 1 strain, which caused acute infection with significant virus shedding in non-vaccinated animals, the subgenotype 2.1 GD191 strain produced different clinical manifestations in weaned piglets and adults. Adult pigs showed subclinical infection with viral shedding, whereas weaned piglets showed overt signs of infection. Efficacy of, and duration of immunity conferred by a C-strain vaccine were assessed using the reference Shimen strain and field isolate GD191 at 12 and 15 months after vaccination. A robust antibody response and sterilising protection were seen in all vaccinated animals and lasted up to 15 months post-vaccination. This study confirms that C-strain vaccines confer both clinical and virological protection against the historical genotype 1 Shimen strain and cross-protection against the prevalent genotype 2 field strain.
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Affiliation(s)
- Qin Wang
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Huanhuan Liu
- Boehringer Ingelheim Vetmedica (China) Co. Ltd., Taizhou 225300, People's Republic of China
| | - Lu Xu
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Junping Li
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Huawei Wu
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Chenghuai Yang
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Xiaochun Chen
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Yong Deng
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China
| | - Yanyong Sun
- Boehringer Ingelheim Vetmedica (China) Co. Ltd., Taizhou 225300, People's Republic of China
| | - Changchun Tu
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun 130122, People's Republic of China
| | - Ning Chen
- Boehringer Ingelheim Vetmedica (China) Co. Ltd., Taizhou 225300, People's Republic of China.
| | - Wenjie Gong
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun 130122, People's Republic of China; Key Laboratory of Zoonoses Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, People's Republic of China.
| | - Guanghua Chen
- Office International des Epizooties/National Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, People's Republic of China.
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13
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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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Shimizu Y, Hayama Y, Murato Y, Sawai K, Yamaguchi E, Yamamoto T. Epidemiology of Classical Swine Fever in Japan-A Descriptive Analysis of the Outbreaks in 2018-2019. Front Vet Sci 2020; 7:573480. [PMID: 33195567 PMCID: PMC7536261 DOI: 10.3389/fvets.2020.573480] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/18/2020] [Indexed: 11/13/2022] Open
Abstract
This study describes the epidemiological characteristics of classical swine fever (CSF) outbreaks in Japan. The first case was confirmed in September 2018, 26 years after the last known case. Outbreaks occurred on 39 farms, 34 commercial farms, and 5 non-commercial farms, between September 2018 and August 2019. In this study, a descriptive analysis was conducted of the epidemiological data on the characteristics of the affected farms, clinical manifestations, intra-farm transmission, association with infected wild boars, and control measures implemented on the farms. Twenty-eight of the 34 affected commercial farms were farrow-to-finish farms. It was assumed that the major risk factors were frequent human-pig interactions and the movement of pigs between farms. Fever and leukopenia were commonly observed in infected pigs. In 12 out of 18 farms where clinical manifestations among fattening pigs was the reason for notification, death was the most frequent clinical manifestation, but the proportion of dead animals did not exceed 0.5% of the total number of animals at most of the affected farms. Therefore, the clinical form of CSF in Japan was considered to be sub-acute. Twenty-three of the 29 farms (79%) with pigs at multiple stages (i.e., piglets, fattening pigs, and sows), had infection across the multiple stages. Many of these farms were within 5 km of the site where the first infected wild boars had been discovered, suggesting that infected wild boars were the source of infection. Infections still occurred at farms that had implemented measures at their farm boundaries to prevent the introduction of the virus into their farms, such as disinfection of vehicles and people, changing boots of the workers, and installation of perimeter fences. It is necessary to continue to strengthen biosecurity measures for farms located in areas with infected wild boars and to continue monitoring the distribution of infected wild boars so that any abnormalities can be reported and inspected at an early stage.
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Affiliation(s)
- Yumiko Shimizu
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Yoko Hayama
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Yoshinori Murato
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Kotaro Sawai
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Emi Yamaguchi
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Takehisa Yamamoto
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
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Fukai K, Nishi T, Yamada M, Ikezawa M. Toward better control of classical swine fever in wild boars: susceptibility of boar-pig hybrids to a recent Japanese isolate and effectiveness of a bait vaccine. Vet Res 2020; 51:96. [PMID: 32736657 PMCID: PMC7393845 DOI: 10.1186/s13567-020-00821-w] [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: 05/18/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
We analyzed the pathogenicity of a recent Japanese classical swine fever virus (CSFV) to wild boars via an experimental infection using boar-pig hybrids as an alternative to wild boars. We also investigated the effectiveness of a bait vaccine against the CSFV. Naïve boar-pig hybrids and pigs showed clinical signs such as fever, leucopenia, anorexia and conjunctivitis following the experimental infection. In contrast, the boar-pig hybrids administered the bait vaccine did not show any clinical signs. Our data indicated that boar-pig hybrids and domestic pigs have similar susceptibility to the recent Japanese CSFV. Additionally, the bait vaccine is effective against the CSFV.
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Affiliation(s)
- Katsuhiko Fukai
- Exotic Disease Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, 6-20-1 Josui-honcho, Kodaira, Tokyo, 187-0022, Japan.
| | - Tatsuya Nishi
- Exotic Disease Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, 6-20-1 Josui-honcho, Kodaira, Tokyo, 187-0022, Japan
| | - Manabu Yamada
- National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan
| | - Mitsutaka Ikezawa
- National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan
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A Polyuridine Insertion in the 3' Untranslated Region of Classical Swine Fever Virus Activates Immunity and Reduces Viral Virulence in Piglets. J Virol 2020; 94:JVI.01214-19. [PMID: 31645448 PMCID: PMC6955259 DOI: 10.1128/jvi.01214-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/11/2019] [Indexed: 01/15/2023] Open
Abstract
Classical swine fever (CSF), a highly contagious viral disease of pigs, is still endemic in some countries of Asia and Central and South America. Considering that the 3′ untranslated region (3′ UTR) plays an important role in flavivirus replication, the present study showed for the first time that a long polyuridine sequence acquired in the 3′ UTR by an endemic CSFV isolate can activate immunity, control viral replication, and modulate disease in piglets. Our findings provide new avenues for the development of novel vaccines against infections with CSF virus and other flaviviruses. Knowledge of molecular virulence determinants is also relevant for future development of rapid and efficient diagnostic tools for the prediction of the virulence of field isolates and for efficient CSF control. Low-virulence classical swine fever virus (CSFV) strains make CSF eradication particularly difficult. Few data are available on the molecular determinants of CSFV virulence. The aim of the present study was to assess a possible role for CSFV virulence of a unique, uninterrupted 36-uridine (poly-U) sequence found in the 3′ untranslated region (3′ UTR) of the low-virulence CSFV isolate Pinar de Rio (PdR). To this end, a pair of cDNA-derived viruses based on the PdR backbone were generated, one carrying the long poly-U insertion in the 3′ UTR (vPdR-36U) and the other harboring the standard 5 uridines at this position (vPdR-5U). Two groups of 20 5-day-old piglets were infected with vPdR-36U and vPdR-5U. Ten contact piglets were added to each group. Disease progression, virus replication, and immune responses were monitored for 5 weeks. The vPdR-5U virus was significantly more virulent than the vPdR-36U virus, with more severe disease, higher mortality, and significantly higher viral loads in serum and body secretions, despite similar replication characteristics in cell culture. The two viruses were transmitted to all contact piglets. Ninety percent of the piglets infected with vPdR-36U seroconverted, while only one vPdR-5U-infected piglet developed antibodies. The vPdR-5U-infected piglets showed only transient alpha interferon (IFN-α) responses in serum after 1 week of infection, while the vPdR-36U-infected piglets showed sustained IFN-α levels during the first 2 weeks. Taken together, these data show that the 3′ UTR poly-U insertion acquired by the PdR isolate reduces viral virulence and activates the innate and humoral immune responses without affecting viral transmission. IMPORTANCE Classical swine fever (CSF), a highly contagious viral disease of pigs, is still endemic in some countries of Asia and Central and South America. Considering that the 3′ untranslated region (3′ UTR) plays an important role in flavivirus replication, the present study showed for the first time that a long polyuridine sequence acquired in the 3′ UTR by an endemic CSFV isolate can activate immunity, control viral replication, and modulate disease in piglets. Our findings provide new avenues for the development of novel vaccines against infections with CSF virus and other flaviviruses. Knowledge of molecular virulence determinants is also relevant for future development of rapid and efficient diagnostic tools for the prediction of the virulence of field isolates and for efficient CSF control.
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Coronado L, Rios L, Frías MT, Amarán L, Naranjo P, Percedo MI, Perera CL, Prieto F, Fonseca-Rodriguez O, Perez LJ. Positive selection pressure on E2 protein of classical swine fever virus drives variations in virulence, pathogenesis and antigenicity: Implication for epidemiological surveillance in endemic areas. Transbound Emerg Dis 2019; 66:2362-2382. [PMID: 31306567 DOI: 10.1111/tbed.13293] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/08/2019] [Accepted: 07/07/2019] [Indexed: 12/14/2022]
Abstract
Classical swine fever (CSF), caused by CSF virus (CSFV), is considered one of the most important infectious diseases with devasting consequences for the pig industry. Recent reports describe the emergence of new CSFV strains resulting from the action of positive selection pressure, due mainly to the bottleneck effect generated by ineffective vaccination. Even though a decrease in the genetic diversity of the positively selected CSFV strains has been observed by several research groups, there is little information about the effect of this selective force on the virulence degree, antigenicity and pathogenicity of this type of strains. Hence, the aim of the current study was to determine the effect of the positive selection pressure on these three parameters of CSFV strains, emerged as result of the bottleneck effects induced by improper vaccination in a CSF-endemic area. Moreover, the effect of the positively selected strains on the epidemiological surveillance system was assessed. By the combination of in vitro, in vivo and immunoinformatic approaches, we revealed that the action of the positive selection pressure induces a decrease in virulence and alteration in pathogenicity and antigenicity. However, we also noted that the evolutionary process of CSFV, especially in segregated microenvironments, could contribute to the gain-fitness event, restoring the highly virulent pattern of the circulating strains. Besides, we denoted that the presence of low virulent strains selected by bottleneck effect after inefficient vaccination can lead to a relevant challenge for the epidemiological surveillance of CSF, contributing to under-reports of the disease, favouring the perpetuation of the virus in the field. In this study, B-cell and CTL epitopes on the E2 3D-structure model were also identified. Thus, the current study provides novel and significant insights into variation in virulence, pathogenesis and antigenicity experienced by CSFV strains after the positive selection pressure effect.
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Affiliation(s)
- Liani Coronado
- Centro Nacional de Sanidad Agropecuaria (CENSA), OIE Collaborating Centre for Diagnosis and Risk Analysis of the Caribbean Region, La Habana, Cuba
| | - Liliam Rios
- Reiman Cancer Research Laboratory, Faculty of Medicine, University of New Brunswick, Saint John, New Brunswick, Canada
| | - María Teresa Frías
- Centro Nacional de Sanidad Agropecuaria (CENSA), OIE Collaborating Centre for Diagnosis and Risk Analysis of the Caribbean Region, La Habana, Cuba
| | - Laymara Amarán
- National Laboratory for Veterinary Diagnostic (NLVD), La Habana, Cuba
| | | | - María Irian Percedo
- Centro Nacional de Sanidad Agropecuaria (CENSA), OIE Collaborating Centre for Diagnosis and Risk Analysis of the Caribbean Region, La Habana, Cuba
| | - Carmen Laura Perera
- Centro Nacional de Sanidad Agropecuaria (CENSA), OIE Collaborating Centre for Diagnosis and Risk Analysis of the Caribbean Region, La Habana, Cuba
| | - Felix Prieto
- National Laboratory for Veterinary Diagnostic (NLVD), La Habana, Cuba
| | | | - Lester J Perez
- Department of Clinical Veterinary Medicine, College of Veterinary Science, University of Illinois, Urbana, IL, USA.,College of Veterinary Science, Veterinary Diagnostic Laboratory (VDL), University of Illinois, Urbana, IL, USA
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18
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Complete Genome Sequences of Classical Swine Fever Virus Subgenotype 2.1 and 2.2 Strains Isolated from Vietnamese Pigs. Microbiol Resour Announc 2019; 8:8/22/e01634-18. [PMID: 31147435 PMCID: PMC6544192 DOI: 10.1128/mra.01634-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Classical swine fever virus (CSFV) strains ND20 and HY78 were detected from infected pigs in the Xuan Truong-Nam Dinh and Hung Yen provinces in North Vietnam in 2014 and 2015, respectively. The most prevalent CSFV subgenotypes in Vietnam are 2.1 and 2.2, and these two complete genome sequences will help the CSFV prevention policy in Vietnam. Classical swine fever virus (CSFV) strains ND20 and HY78 were detected from infected pigs in the Xuan Truong-Nam Dinh and Hung Yen provinces in North Vietnam in 2014 and 2015, respectively. The most prevalent CSFV subgenotypes in Vietnam are 2.1 and 2.2, and these two complete genome sequences will help the CSFV prevention policy in Vietnam. In particular, subgenotype 2.2 (ND20 strain) has been reported less worldwide, so it is worth sharing information about this subgenotype.
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19
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Gong W, Li J, Wang Z, Sun J, Mi S, Lu Z, Cao J, Dou Z, Sun Y, Wang P, Yuan K, Zhang L, Zhou X, He S, Tu C. Virulence evaluation of classical swine fever virus subgenotype 2.1 and 2.2 isolates circulating in China. Vet Microbiol 2019; 232:114-120. [PMID: 31030834 DOI: 10.1016/j.vetmic.2019.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/31/2019] [Accepted: 04/02/2019] [Indexed: 01/01/2023]
Abstract
Classical swine fever (CSF) remains an important pig disease in China, where it usually presents with mild or atypical clinical manifestations, with large scale outbreaks rarely seen. This has led to speculation about the possible circulation of viral strains of low virulence. To investigate this possibility, five field isolates within the predominant genotype 2 (2.1b, 2.1c, 2.1 h and 2.2) were evaluated and compared by experimental infection of naturally farrowed but colostrum-deprived piglets. All infected piglets displayed clinical signs, including persistent high fever, depression, anorexia, dyspnea, conjunctivitis, constipation, and hesitant gait. Typical pathological lesions, including pulmonary edema, hemorrhagic or cellulosic exudation, and swelling and hemorrhage of lymph nodes, were observed. Viremia and Erns protein expression in the blood of all infected animals were detectable from 3 to 5 days post infection (DPI), their presence correlating with the onset of fever, clinical signs and leukopenia. E2 antibody did not develop in any of the field CSFV-infected piglets during the disease course, while Erns antibody was detectable in 4-56% of infected animals at various time points. Mortalities ranged from 20 to 80% within 21 DPI, progressing to 100% by 43 DPI. Based on clinical scores and fatalities within 21 DPI, 2 of the 5 field isolates were classified as of moderate virulence and 3 of high virulence; i.e., no field isolates of low virulence were identified. The study has provided data supporting the use of these isolates as challenge viruses to evaluate the efficacy of current CSF vaccines.
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Affiliation(s)
- Wenjie Gong
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun, PR China
| | - Junhui Li
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Zunbao Wang
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Jiumeng Sun
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun, PR China
| | - Shijiang Mi
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun, PR China
| | - Zongji Lu
- College of Life Sciences and Engineering, Foshan University, Foshan, PR China
| | - Jian Cao
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Zhihua Dou
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Yanjun Sun
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Pengjiang Wang
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Ke Yuan
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Liying Zhang
- College of Animal Sciences, Jilin University, Changchun, PR China
| | - Xubin Zhou
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China
| | - Sun He
- Tecon Biology Joint Stock Company Limited, Urumqi, PR China.
| | - Changchun Tu
- Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun, PR China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
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