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Sheykhi A, Sheikhi N, Charkhkar S, Brujeni GN. Detection and Characterization of Circovirus in Canary Flocks. Avian Dis 2018; 62:137-142. [PMID: 29944404 DOI: 10.1637/11776-120417-regr] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Circovirus infections have been documented in adult and nestling canaries (Fringillidae) but the distribution of the virus in the world is not yet known. In captive canary flocks, Circovirus infections have been reported based on the clinical observations. In this study, the presence of both canary circovirus (CaCV) and chicken anemia virus (CAV) in canary flocks was investigated. Virus strains were detected by PCR and direct sequencing of amplified products. Nucleotide sequences were aligned and compared with existing data in GenBank. PCR identified CaCV-positive birds, giving an overall positivity rate of 25%, but all samples were negative for CAV. According to the sequencing data, three distinct strains were identified. Our results indicated a relationship between genetic variation in the replicase gene ( rep) and the geographic regions as well as the feasibility of using the rep gene for virus detection and molecular epidemiology investigations. We are reporting detection and characterization of canary circovirus based on the rep gene. Sequencing results and sequence identity analysis revealed that the rep gene could be used for detecting and discriminating the members of family Circoviridae. This manuscript is the first report of canary circovirus in Iran and of three new strains in the world.
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Affiliation(s)
- Abdulmajid Sheykhi
- A Department of Clinical Science, College of Veterinary, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran, Post code: 1477893855
| | - Nariman Sheikhi
- A Department of Clinical Science, College of Veterinary, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran, Post code: 1477893855
| | - Saeid Charkhkar
- A Department of Clinical Science, College of Veterinary, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran, Post code: 1477893855
| | - Gholamreza Nikbakht Brujeni
- B Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran: 1417614418
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Liu X, Ouyang T, Ma T, Ouyang H, Pang D, Ren L. Immunogenicity evaluation of inactivated virus and purified proteins of porcine circovirus type 2 in mice. BMC Vet Res 2018; 14:137. [PMID: 29685143 PMCID: PMC5913788 DOI: 10.1186/s12917-018-1461-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/16/2018] [Indexed: 01/08/2023] Open
Abstract
Background Vaccination is considered as an effective and economical way to against PCV2 infection. However, some of commercial available vaccines are based on inactivated viruses, while the others are based on purified protein of PCV2. In the present study, we aimed to compare the immunogenicity of inactivated virus and purified proteins of porcine circovirus type 2 in mice. Results The results showed that positive antiserum titers were significantly increased after second, third and fourth immunization using inactivated PCV2 or purified proteins as coating antigen. Moreover, the inactivated PCV2 induced significantly higher levels of PCV2-specific antibodies than that of PCV2 subunit proteins. After PCV2 wild strain challenged, the average daily gain was comparable with that of mice in the mock group, and the sera from both inactivated PCV2-immunized animals and subunit protein Cap+ORF3 + Rep immunized animals had significantly higher neutralizing antibody titers than that of the PBS group. As expected, the neutralizing antibody in the inactivated PCV2 group was significantly higher than that of the subunit protein group. These results indicated that positive antiserum induced by the inactivated PCV2 had a better reactivity and specificity than that of the positive antiserum induced by the purified proteins. Conclusions The results in the present study demonstrated inactivated PCV2 is more effective than PCV2 subunit proteins in stimulating immune response to against PCV2 infection.
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Affiliation(s)
- Xiaohui Liu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China
| | - Ting Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China
| | - Teng Ma
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China
| | - Hongsheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China
| | - Daxin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China
| | - Linzhu Ren
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, China.
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Peng Z, Ma T, Pang D, Su D, Chen F, Chen X, Guo N, Ouyang T, Ouyang H, Ren L. Expression, purification and antibody preparation of PCV2 Rep and ORF3 proteins. Int J Biol Macromol 2016; 86:277-81. [PMID: 26812108 DOI: 10.1016/j.ijbiomac.2016.01.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 12/27/2015] [Accepted: 01/21/2016] [Indexed: 11/18/2022]
Abstract
Rep and ORF3 proteins are important functional proteins of porcine circovirus 2 (PCV2). Here, Rep and ORF3 genes were cloned, expressed and used to raise polyclonal antibodies. The result showed the recombinant plasmids of Rep and ORF3 genes constructed in this study were expressed efficiently in the prokaryotic system, and the recombinant proteins had antigenicity and immunogenicity. Furthermore, reactivity and specificity of the antiserums were characterized by western blot and indirect immunofluorescent assays. The results elucidated that polyclonal antiserum prepared with Rep or ORF3 had good reactivity and specificity against PCV2, or the Rep and ORF3 expressed in PK-15 cells, respectively. The Rep protein is promising for PCV2 antibody and vaccine development. These results will be helpful for further studies focusing on pathogenesis of PCV2 and serology diagnostic test or vaccine development against PCV2.
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Affiliation(s)
- Zhiyuan Peng
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Teng Ma
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Daxin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Dan Su
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Fuwang Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Xinrong Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Ning Guo
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Ting Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Hongsheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China
| | - Linzhu Ren
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, Jilin 130062, China.
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Constans M, Ssemadaali M, Kolyvushko O, Ramamoorthy S. Antigenic Determinants of Possible Vaccine Escape by Porcine Circovirus Subtype 2b Viruses. Bioinform Biol Insights 2015; 9:1-12. [PMID: 26339187 PMCID: PMC4550186 DOI: 10.4137/bbi.s30226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/05/2015] [Accepted: 07/07/2015] [Indexed: 12/20/2022] Open
Abstract
Currently available commercial vaccines against porcine circovirus strain 2 (PCV2) solely target the PCV2a genotype. While PCV2 vaccines are highly effective in preventing clinical signs, PCV2b has dominated over the PCV2a genotype in prevalence, corresponding with the introduction of PCV2a vaccines. A recently emerged PCV2b recombinant with an additional amino acid in the capsid protein, designated the mutant PCV2b (mPCV2b), is cause for concern due to its increased virulence and rapid spread. The accumulation of recent evidence for the increased genetic diversity in PCV2 suggests that current vaccines against PCV2a may be inducing selection pressure and driving viral evolution. In this study, the hypothesis that differences in key immune epitopes between the PCV2a vaccine strains, a classical PCV2b strain called PCV2b 41513 obtained from a vaccine-failure case, and mPCV2b strains could promote vaccine escape was tested using immuno-informatic tools. In the major viral proteins, 9 of the 18 predicted swine leukocyte antigens (SLA) class-I epitopes, 8 of the 22 predicted SLA class-II epitopes, and 7 of the 25 predicted B cell epitopes varied between the vaccine and field strains. A majority of the substitutions in both the T- and B-cell epitopes were located in the capsid protein. Some B- and T-cell epitopes that were identified as immunogenic in the vaccine strain were not identified as epitopes in the field strains, indicating a subtle shift in the antigenic profile of the field strains. Several nonconserved epitopes had both predicted B- and T-cell functions. Therefore, substitutions in the dual epitopes could affect both arms of the immune response simultaneously, causing immune escape. Our findings support further rational design of PCV2 vaccines to increase the current threshold of protection.
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Affiliation(s)
- Megan Constans
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Marvin Ssemadaali
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Oleksandr Kolyvushko
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND, USA
| | - Sheela Ramamoorthy
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND, USA
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