1
|
Sirisereewan C, Nguyen TC, Janetanakit T, Kedkovid R, Thanawongnuwech R. Emergence of novel porcine circovirus 2d strains in Thailand, 2019-2020. Front Vet Sci 2023; 10:1170499. [PMID: 37408832 PMCID: PMC10318142 DOI: 10.3389/fvets.2023.1170499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/05/2023] [Indexed: 07/07/2023] Open
Abstract
Porcine circovirus 2 (PCV2) has been recognized as a causative agent of porcine circovirus diseases (PCVDs) affecting the global swine industry. In this study, the genetic diversity of PCV2 strains circulating in Thailand between 2019 and 2020 was investigated using 742 swine clinical samples from 145 farms. The results showed PCV2-positive rates of 54.2% (402/742) and 81.4% (118/145) at the sample and farm levels, respectively. Genetic analysis of 51 Thai PCV2 genomic sequences showed that 84.3% (43/51) was PCV2d, 13.7% (7/51) was PCV2b and 1.9% (1/51) was PCV2b/2d recombinant virus. Surprisingly, the majority of the Thai PCV2d sequences from this study (69.77%, 30/43) formed a novel cluster on a phylogenetic tree and contained a unique 133HDAM136 on the ORF2 deduced amino acid sequence, which is in one of the previously identified immunoreactive domains strongly involved in virus neutralization. The PCV2b/2d recombinant virus also carried 133HDAM136. The emergence of the novel PCV2d strains predominating in Thailand was discussed. This study highlights the need for further investigations on the spreading of these PCV2d strains in other regions and the efficacy of current commercial vaccines.
Collapse
Affiliation(s)
- Chaitawat Sirisereewan
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Thanh Che Nguyen
- The International Graduate Program of Veterinary Science and Technology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Taveesak Janetanakit
- Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals and One Health Research Cluster, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Roongtham Kedkovid
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Center of Excellence in Swine Reproduction, Chulalongkorn University, Bangkok, Thailand
| | - Roongroje Thanawongnuwech
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals and One Health Research Cluster, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| |
Collapse
|
2
|
Luka PD, Adedeji AJ, Jambol AR, Ifende IV, Luka HG, Choji ND, Weka R, Settypalli TBK, Achenbach JE, Cattoli G, Lamien CE, Molini U, Franzo G, Dundon WG. Coinfections of African swine fever virus, porcine circovirus 2 and 3, and porcine parvovirus 1 in swine in Nigeria. Arch Virol 2022; 167:2715-2722. [PMID: 36138234 DOI: 10.1007/s00705-022-05593-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/05/2022] [Indexed: 12/14/2022]
Abstract
As pig production increases in Africa, it is essential to identify the pathogens that are circulating in the swine population to assess pig welfare and implement targeted control measures. For this reason, DNA samples collected from pigs in Nigeria in the context of African swine fever monitoring were further screened by PCR for porcine circovirus 2 (PCV-2), porcine circovirus 3 (PCV-3), and porcine parvovirus 1 (PPV1). Forty-seven (45%) pigs were positive for two or more pathogens. Sequence analysis identified PCV-2 genotypes a, b, and d, while limited genetic heterogenicity was observed among PCV-3 strains. All except one of the PPV1 sequences were genetically distinct from those previously identified in other countries.
Collapse
Affiliation(s)
| | | | - Anvou R Jambol
- National Veterinary Institute, Vom, Plateau State, Nigeria
| | | | - Helen G Luka
- National Veterinary Institute, Vom, Plateau State, Nigeria
| | - Nyam D Choji
- National Veterinary Institute, Vom, Plateau State, Nigeria
| | - Rebecca Weka
- National Veterinary Institute, Vom, Plateau State, Nigeria
| | - Tirumala B K Settypalli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, PO Box 100, 1400, Vienna, Austria
| | | | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, PO Box 100, 1400, Vienna, Austria
| | - Charles E Lamien
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, PO Box 100, 1400, Vienna, Austria
| | - Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia.,Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek, Namibia
| | - Giovanni Franzo
- Dept. of Animal Medicine, Production and Health, University of Padova, Legnaro, viale dell'Università 16, 35020, Padova, Italy
| | - William G Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, PO Box 100, 1400, Vienna, Austria. .,Animal Production and Health Laboratory, IAEA, Friedenstrasse, 1, 2444, Seibersdorf, Austria.
| |
Collapse
|
3
|
Molecular Detection and Genetic Characterization of Porcine Circovirus 2 (PCV-2) in Black-Backed Jackal (Lupulella mesomelas) in Namibia. Animals (Basel) 2022; 12:ani12050620. [PMID: 35268189 PMCID: PMC8909721 DOI: 10.3390/ani12050620] [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: 02/07/2022] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 11/16/2022] Open
Abstract
Members of the genus Circovirus have been identified in several host species. While initially considered host-specific, there is growing evidence of their presence in unexpected hosts. Porcine circovirus 2 (PCV-2) is no exception, having been reported in animals belonging to different orders, including carnivores. Recently, PCV-2 was detected in domestic pigs, warthogs and antelopes in Namibia. Considering the potential contact between these populations and wild carnivores, the presence of PCV-2 was investigated in 32 black-backed jackals (Lupulella mesomelas) shot between February and July 2021 as part of predator control operations in Namibia. Two lung lymph nodes tested positive for PCV-2 by PCR, confirming the broader-than-expected PCV-2 host tropism and the susceptibility of canids. Sequence analysis demonstrated a close association between the PCV-2s identified in the jackals and PCV-2b strains collected from South African domestic pigs. Although several hypotheses regarding the source of the jackal’s infection are proposed, further studies should be performed to properly assess how PCV-2 is acquired and maintained in the wild and its potential impact on wild and domestic species.
Collapse
|
4
|
Molecular Epidemic Characteristics and Genetic Evolution of Porcine Circovirus Type 2 (PCV2) in Swine Herds of Shanghai, China. Viruses 2022; 14:v14020289. [PMID: 35215883 PMCID: PMC8879946 DOI: 10.3390/v14020289] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/17/2022] [Accepted: 01/26/2022] [Indexed: 02/07/2023] Open
Abstract
Porcine Circovirus 2 (PCV2) is a crucial swine pathogen and considered a primary causative agent of porcine circovirus-associated diseases (PCVADs), posing a serious economic threat to the swine industry across globe. The world’s biggest agricultural conglomerates have teamed up to create giant commercial pig farms across Shanghai due to the proximity of this region to more affluent lean-pork markets. Since its discovery, PCV2 has displayed extraordinary genetic diversity, and its genome is swiftly evolving through a series of mutations and recombinations. However, limited information on epidemiology, molecular characteristics, vaccine cross-protection, and the co-infection rate of PCV2 with other lethal swine diseases can adversely impact the pig production in the region. To investigate the molecular epidemic characteristics and genetic evolution of PCV2, pigs with doubtful symptoms of PCVADs were sampled from various commercial pig farms with a history of PWMS and/or PDNS across Shanghai from 2014 to 2018. Our results revealed the coexistence of multiple PCV2 genotypes (PCV2b, PCV2e, and PCV2d) among Shanghai pig herds and dominance of PCV2d among them. We also found critical amino acid substitutions in epitope regions of important capsid proteins in PCV2 isolates involved in viral replication and host immune escape. Spotted mutations may favor the prevalence and survival of various PCV2 genotypes despite availability of commercial vaccines. This study also provides insight into the co-infection status of PCV2 with major lethal swine viral diseases such as PPV and PPRSV. Collectively, these investigations will contribute to understanding the molecular epidemiology and evolution of PCV2 across the region.
Collapse
|
5
|
Lim J, Jin M, Yoon I, Yoo HS. Efficacy of bivalent vaccines of porcine circovirus type 2 and Mycoplasma hyopneumoniae in specific pathogen-free pigs challenged with porcine circovirus type 2d. J Vet Sci 2022; 23:e49. [PMID: 35618321 PMCID: PMC9149493 DOI: 10.4142/jvs.21287] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/16/2022] [Accepted: 03/25/2022] [Indexed: 11/20/2022] Open
Abstract
Background Porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHP) are economically significant pathogens in the pig industry. The use of combined vaccines against PCV2 and MHP is one of the most effective ways of protecting pigs from both diseases, and it has become a part of general management. Objectives This study evaluated the efficacy of two new bivalent vaccines of PCV2 and MHP (Myco-X and Myco-XD) in SPF pigs. Myco-X and Myco-XD are a combined vaccine of MHP with PCV2b and PCV2d, respectively. Methods Sixteen pigs were divided into four groups: Myco-X-vaccinated challenged, Myco-XD-vaccinated challenged, unvaccinated challenged, and unvaccinated unchallenged. Two milliliters of Myco-X were administered intramuscularly, and 0.5 mL of Myco-XD was injected intradermally at 3 wk of age. The pigs were challenged with virulent PCV2d via the intramuscular and intranasal route 4 wk post-vaccination. Results All vaccinated pigs showed effective reduction of the clinical signs, the PCV2d load in the blood and nasal swab samples, as well as lung and lymphoid tissue lesions in the challenge test. Compared to unvaccinated challenged animals, the vaccinated challenged animals showed significantly higher (p < 0.05) levels of anti-PCV2 IgG, PCV2d-specific interferon-γ (IFN-γ), and anti-MHP IgG. Conclusions Based on clinical, microbiological, serological, and pathological assessments, this study confirmed that both combined vaccines could protect pigs against PCV2 infection caused by PCV2d. On the other hand, further research on the efficacy evaluation of these new vaccines against the MHP challenge and PCV2d/MHP co-challenge is needed.
Collapse
Affiliation(s)
- Jeonggyo Lim
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
- Choong Ang Vaccine Laboratories Co., Ltd., Daejeon 34055, Korea
| | - Myongha Jin
- Choong Ang Vaccine Laboratories Co., Ltd., Daejeon 34055, Korea
| | - Injoong Yoon
- Choong Ang Vaccine Laboratories Co., Ltd., Daejeon 34055, Korea
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
- BK21 FOUR Future Veterinary Medicine Leading Education and Research Center, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
6
|
Franzo G, Settypalli TBK, Agusi ER, Meseko C, Minoungou G, Ouoba BL, Habibata ZL, Wade A, de Barros JL, Tshilenge CG, Gelaye E, Yami M, Gizaw D, Chibssa TR, Anahory IV, Mapaco LP, Achá SJ, Ijomanta J, Jambol AR, Adedeji AJ, Luka PD, Shamaki D, Diop M, Bakhoum MT, Lo MM, Chang'a JS, Magidanga B, Mayenga C, Ziba MW, Dautu G, Masembe C, Achenbach J, Molini U, Cattoli G, Lamien CE, Dundon WG. Porcine circovirus-2 in Africa: Identification of continent-specific clusters and evidence of independent viral introductions from Europe, North America and Asia. Transbound Emerg Dis 2021; 69:e1142-e1152. [PMID: 34812571 DOI: 10.1111/tbed.14400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/02/2021] [Accepted: 11/11/2021] [Indexed: 01/16/2023]
Abstract
Porcine circovirus-2 (PCV-2) is associated with several disease syndromes in domestic pigs that have a significant impact on global pig production and health. Currently, little is known about the status of PCV-2 in Africa. In this study, a total of 408 archived DNA samples collected from pigs in Burkina Faso, Cameroon, Cape Verde, Ethiopia, the Democratic Republic of the Congo, Mozambique, Nigeria, Senegal, Tanzania and Zambia between 2000 and 2018 were screened by PCR for the presence of PCV-2. Positive amplicons of the gene encoding the viral capsid protein (ORF2) were sequenced to determine the genotypes circulating in each country. Four of the nine currently known genotypes of PCV-2 were identified (i.e. PCV-2a, PCV-2b, PCV-2d and PCV-2 g) with more than one genotype being identified in Burkina Faso, Ethiopia, Nigeria, Mozambique, Senegal and Zambia. Additionally, a phylogeographic analysis which included 38 additional ORF2 gene sequences of PCV-2s previously identified in Mozambique, Namibia and South Africa from 2014 to 2016 and 2019 to 2020 and available in public databases, demonstrated the existence of several African-specific clusters and estimated the approximate time of introduction of PCV-2s into Africa from other continents. This is the first in-depth study of PCV-2 in Africa and it has important implications for pig production at both the small-holder and commercial farm level on the continent.
Collapse
Affiliation(s)
- Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Legnaro, Italy
| | - Tirumala B K Settypalli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Centre, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | | | - Clement Meseko
- National Veterinary Research Institute, Vom, Plateau State, Nigeria
| | | | | | | | - Abel Wade
- National Veterinary Laboratory (LANAVET), Garoua, Cameroon
| | - José Luís de Barros
- Direction Génerale de l`Agriculture, Sylviculture et Élèvage, Direction des Services Vétérinaires, Cape Verde
| | | | - Esayas Gelaye
- National Veterinary Institute (NVI), Debre Zeit, Ethiopia
| | - Martha Yami
- National Veterinary Institute (NVI), Debre Zeit, Ethiopia
| | - Daniel Gizaw
- National Animal Health Diagnostic and Investigation Center (NAHDIC), Sebeta, Ethiopia
| | | | - Iolanda Vieira Anahory
- Directorate of Animal Science, Central Veterinary Laboratory, Agrarian Research Institute of Mozambique, Maputo, Mozambique
| | - Lourenço P Mapaco
- Directorate of Animal Science, Central Veterinary Laboratory, Agrarian Research Institute of Mozambique, Maputo, Mozambique
| | - Sara J Achá
- Directorate of Animal Science, Central Veterinary Laboratory, Agrarian Research Institute of Mozambique, Maputo, Mozambique
| | | | | | | | - Pam Dachung Luka
- National Veterinary Research Institute, Vom, Plateau State, Nigeria
| | - David Shamaki
- National Veterinary Research Institute, Vom, Plateau State, Nigeria
| | - Mariame Diop
- Laboratoire National de l'Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar, Sénégal
| | - Mame Thierno Bakhoum
- Laboratoire National de l'Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar, Sénégal
| | - Modou Moustapha Lo
- Laboratoire National de l'Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar, Sénégal
| | - Jelly S Chang'a
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dares Salaam, Tanzania
| | - Bishop Magidanga
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dares Salaam, Tanzania
| | - Charles Mayenga
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dares Salaam, Tanzania
| | - Maureen Wakwamba Ziba
- Department of Veterinary Services Ministry of Fisheries and Livestock, Central Veterinary Research Institute, Lusaka, Zambia
| | - George Dautu
- Department of Veterinary Services Ministry of Fisheries and Livestock, Central Veterinary Research Institute, Lusaka, Zambia
| | - Charles Masembe
- College of Natural Sciences, Makerere University, Kampala, Uganda
| | | | - Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia.,Central Veterinary Laboratory (CVL), Windhoek, Namibia
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Centre, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | - Charles E Lamien
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Centre, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | - William G Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Centre, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| |
Collapse
|
7
|
Molini U, Coetzee LM, Hemberger MY, Khaiseb S, Cattoli G, Dundon WG, Franzo G. The Oryx Antelope ( Oryx gazella): An Unexpected Host for Porcine Circovirus-2 (PCV-2). Pathogens 2021; 10:pathogens10111402. [PMID: 34832558 PMCID: PMC8621338 DOI: 10.3390/pathogens10111402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
For several years after its discovery, Porcine circovirus 2 (PCV-2) represented a major threat to the swine industry through economic losses due to the associated clinical syndromes, decreased production performances in both symptomatic and asymptomatic animals and disease management costs. Widespread vaccination administration has largely reduced the impact of this infection and represents the most effective control measure. The efficacy of vaccination is threatened by the emergence of novel (or uncommon) PCV-2 genotypes. In addition to domestic pigs, PCV-2 has been detected in several other species, a fact which could have an impact on new variant emergence and maintenance. Considering this, the present study assessed the distribution of the minor PCV-2c genotype in non-Suidae ungulates in Namibia. Red hartebeests (Alcelaphus buselaphus caama) (n = 44), kudus (Tragelaphus strepsiceros) (n = 10) and oryxes (Oryx gazella) (n = 54), whose mediastinal lymph nodes were sampled after slaughtering during the period 2019–2021, were included in the study. Two oryxes (3.7%; 95% CI = 0.45–12.75%) were PCV-2-positive by PCR. Complete genome sequence was obtained for the two samples identifying them as PCV-2c genotype. The sequences were identical and shared a high percentage of identity (~99.9%) with those recently obtained from warthogs living in the same area. The present study confirms the presence of the PCV-2c genotype (previously considered extinct) in Namibian wild animal populations and demonstrates greater than expected PCV-2 host plasticity. Because of the role these niches can have in the maintenance and evolution of minor PCV-2 genotypes, more extensive and dedicated studies should be performed to prepare authorities to promptly react to potential emerging threats from these viruses.
Collapse
Affiliation(s)
- Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, Neudamm Campus, University of Namibia, Windhoek 13301, Namibia; (U.M.); (M.Y.H.)
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Windhoek 18137, Namibia; (L.M.C.); (S.K.)
| | - Lauren Michelle Coetzee
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Windhoek 18137, Namibia; (L.M.C.); (S.K.)
| | - Maria Yvonne Hemberger
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, Neudamm Campus, University of Namibia, Windhoek 13301, Namibia; (U.M.); (M.Y.H.)
| | - Siegfried Khaiseb
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Windhoek 18137, Namibia; (L.M.C.); (S.K.)
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria; (G.C.); (W.G.D.)
| | - William G. Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria; (G.C.); (W.G.D.)
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Viale dell’Università, 35020 Legnaro, Italy
- Correspondence:
| |
Collapse
|
8
|
Mutation of the sixth amino acid of the Rep protein has no effect on porcine circovirus 2b but enhances porcine circovirus 2d replication in vitro. Arch Virol 2021; 166:3189-3192. [PMID: 34524537 DOI: 10.1007/s00705-021-05217-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/27/2021] [Indexed: 11/26/2022]
Abstract
Porcine circovirus type 2 (PCV2) is the etiological agent of post-weaning multisystemic wasting syndrome (PMWS). The original prevalent genotype, PCV2a, has been replaced by genotypes 2b and 2d in the swine population worldwide. The Rep protein is critical for viral replication. Comparison of a large number of Rep protein amino acid (aa) sequences showed that three sites distinguish genotype 2b from genotype 2d. In order to analyze the effect of exchanging the amino acids (asparagine and serine) at position 6 in the Rep proteins of PCV2b and PCV2d, two wild-type and two mutant viruses were rescued. Real-time quantitative PCR and a one-step growth curve were used to determine the viral load to assess the replication ability of the rescued viruses. The results showed that there was no significant difference in in vitro performance between the wild-type PCV2b and the mutated virus, while the mutation of PCV2d enhanced viral replication.
Collapse
|
9
|
Molini U, Franzo G, Gous L, Moller S, Hemberger YM, Chiwome B, Marruchella G, Khaiseb S, Cattoli G, Dundon WG. Three different genotypes of porcine circovirus 2 (PCV-2) identified in pigs and warthogs in Namibia. Arch Virol 2021; 166:1723-1728. [PMID: 33721098 DOI: 10.1007/s00705-021-05035-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 01/24/2021] [Indexed: 01/31/2023]
Abstract
Porcine circovirus 2 (PCV-2) is the causative agent of porcine circovirus diseases (PCVD). A study was undertaken to determine whether PCV-2 was present in samples collected from commercial pigs (n = 46) and warthogs (n = 42) in Namibia between 2019 and 2020. Twenty-three of the collected samples were positive by PCR (13 from pigs and 10 from warthogs), and a phylogenetic analysis of ORF2 identified three genotypes (PCV-2b and PCV-2d in pigs and PCV-2c in warthogs). This is the first time that PCV-2 has been identified in warthogs and in Namibia. It is also the first report of PCV-2c in Africa.
Collapse
Affiliation(s)
- Umberto Molini
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia.,Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek, Namibia
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, viale dell'Università 16, 35020, Legnaro, Italy
| | - Lené Gous
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia
| | - Sjandré Moller
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia
| | - Yvonne Maria Hemberger
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia
| | - Bernard Chiwome
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia
| | - Giuseppe Marruchella
- Faculty of Veterinary Medicine, University of Teramo, Loc. Piano d'Accio S.P. 18, 64100, Teramo, Italy
| | - Siegfried Khaiseb
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek, Namibia
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Freidenstrasse, 1, Seibersdorf 2444, PO Box 100, 1400, Vienna, Austria
| | - William G Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Freidenstrasse, 1, Seibersdorf 2444, PO Box 100, 1400, Vienna, Austria.
| |
Collapse
|
10
|
Genetic and phylogenetic analysis of porcine circovirus type 2 on Jeju Island, South Korea, 2019-2020: evidence of a novel intergenotypic recombinant. Arch Virol 2021; 166:1093-1102. [PMID: 33570666 DOI: 10.1007/s00705-020-04948-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 12/17/2020] [Indexed: 10/22/2022]
Abstract
Porcine circovirus type 2 (PCV2) is the most ubiquitous viral pathogen of pigs and has persistently affected the global swine industry. Since first being identified in South Korea in 1999, the virus has undergone considerable genetic change and genotype shifts during the past two decades. These events have contributed to the coexistence of genotypes PCV2a, PCV2b, and PCV2d in Korean pig populations, which may promote viral recombination. The genotypic and phylogenetic characteristics of PCV2 strains circulating in pig herds on Jeju Island from 2019 to 2020 were the focus of this study. Genotype-specific PCR indicated that PCV2d is the dominant viral genotype and that coinfections with PCV2d and PCV2a (75%) or PCV2a and PCV2b (25%) are common in provincial pig herds. The complete genome sequences of 11 PCV2 strains, including three PCV2a, two PCV2b, and six PCV2d strains, were determined. A genomic comparison showed that all of the viruses had the highest nucleotide sequence identity to their corresponding genotypic reference strain. Notably, genetic and phylogenetic analysis revealed that one PCV2d strain, KNU-1931, exhibited nucleotide sequence variation in the ORF1 gene when compared to other PCV2d strains but showed a high degree of similarity to the PCV2b strains. Comprehensive recombination analysis suggested that KNU-1931 originated from natural recombination within ORF1 between PCV2b (the minor parent) and PCV2d (the major parent) strains. Our findings provide information about the frequency of genetic recombination between two different PCV2 genotypes circulating in the field domestically, illustrating the importance of continual intergenotypic recombination for viral fitness when multiple genotypes are present.
Collapse
|
11
|
Evaluation of novel recombinant porcine circovirus type 2d (PCV2d) vaccine in pigs naturally infected with PCV2d. Vaccine 2020; 39:529-535. [PMID: 33342633 DOI: 10.1016/j.vaccine.2020.12.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 11/22/2022]
Abstract
INTRODUCTION The pathogenic porcine circovirus type 2 (PCV2) causes significant economic losses in pig production. Emergence of the PCV2d genotype has been linked with PCV2-associated disease (PCVAD) outbreaks. However, no study has been conducted efficacy of an experimental PCV2d-based subunit vaccine in pigs. Therefore, PCV2b- and PCV2d-based capsid (CP) proteins were generated using a baculovirus (Bac) expression system, and we evaluated the protective immune responses in a commercial pig farm where predominant PCV2d is circulating. METHODS Eighteen 3-week-old pigs with maternal antibodies were randomly divided into four groups, and were immunized with purified Bac-2dCP, mixed 1:1 ratio with purified Bac-2bCP and Bac-2dCP (Bac-mCP), a commercial PCV2a-based subunit vaccine (VAC) or phosphate-buffered saline (PBS) as controls. RESULTS The Bac-2dCP and Bac-mCP groups had significantly higher PCV2b- or PCV2d- specific IgG and neutralizing antibody without interference by maternal antibody compared to control group in pigs naturally infected with PCV2d. Interestingly, not only serum IL-4 level was significantly increased in the Bac-2dCP group, but also PCV2d viremia level was significantly reduced than the control group. CONCLUSIONS The recombinant Bac-2dCP subunit vaccine is a good candidate for the effective reduction against PCV2d infection.
Collapse
|
12
|
Wang Y, Noll L, Porter E, Stoy C, Dong J, Anderson J, Fu J, Pogranichniy R, Woodworth J, Peddireddi L, Bai J. Development of a differential multiplex real-time PCR assay for porcine circovirus type 2 (PCV2) genotypes PCV2a, PCV2b and PCV2d. J Virol Methods 2020; 286:113971. [PMID: 32926893 PMCID: PMC7486290 DOI: 10.1016/j.jviromet.2020.113971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 11/18/2022]
Abstract
A multiplex real-time PCR (mqPCR) is developed for PCV2a, 2b, and 2d differentiations. Sequencing of 74 strains confirmed genotyping results generated by the mqPCR. The mqPCR did not detect any non-target swine pathogens included in this study. This genotyping assay is recommended following a general PCV2 diagnostic testing.
A multiplex quantitative real-time polymerase chain reaction (mqPCR) assay was developed and validated for detection and differentiation of porcine circovirus type 2 (PCV2) genotypes, PCV2a, PCV2b and PCV2d. Single nucleotide polymorphism in primers or probes was deployed for different genotype detections, while conserved sequence in the 3' end of a primer and in the middle of a probe was used for the targeted genotype. In silico analysis of 2601 PCV2 ORF2 sequences showed that the predicted strain coverage of the assay was 93.4 % (409/438) for PCV2a, 95.1 % (1161/1221) for PCV2b and 93.6 % (882/942) for PCV2d strains. The PCR amplification efficiencies were 94.5 %, 100.2 %, and 99.2 % for PCV2a, PCV2b and PCV2d, respectively, with correlation coefficients >0.995 for all genotypes. The limits of detection (LOD) were 1.58 × 10−4 TCID50/mL for PCV2a, 5.62 × 10−4 TCID50/mL for PCV2b, and 3.16 × 10−3 TCID50/mL for PCV2d. Sanger sequencing of 74 randomly selected PCV2 positive clinical samples confirmed the genotypes of strains identified by the mqPCR. Validation with clinical samples co-positive for target and non-target pathogens demonstrated that the mqPCR assay specifically detected targeted viruses without cross reacting to each other or to other common porcine viruses.
Collapse
Affiliation(s)
- Yin Wang
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA; Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Lance Noll
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Elizabeth Porter
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Colin Stoy
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Junsheng Dong
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Joe Anderson
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Jinping Fu
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA
| | - Roman Pogranichniy
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA; Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jason Woodworth
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS, USA
| | - Lalitha Peddireddi
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA; Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Jianfa Bai
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, KS, USA; Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA.
| |
Collapse
|
13
|
Influence of the Fermented Feed and Vaccination and Their Interaction on Parameters of Large White/Norwegian Landrace Piglets. Animals (Basel) 2020; 10:ani10071201. [PMID: 32679752 PMCID: PMC7401620 DOI: 10.3390/ani10071201] [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: 06/02/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 12/18/2022] Open
Abstract
The aim of this study was to evaluate the influence of fermented with a newly isolated lactic acid bacteria (LAB) strains combination (Lactobacillus plantarum LUHS122, Lactobacillus casei LUHS210, Lactobacillus farraginis LUHS206, Pediococcus acidilactici LUHS29, Lactobacillus plantarum LUHS135 and Lactobacillus uvarum LUHS245) feed on non-vaccinated (NV) and vaccinated with Circovac porcine circovirus type 2 vaccine (QI09AA07, CEVA-PHYLAXIA Co. Ltd. Szállás u. 5. 1107 Budapest, Hungary) piglets' blood parameters, gut microbial composition, growth performance and ammonia emission. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets, which were randomly divided into four groups with 100 piglets each: SnonV-non-vaccinated piglets fed with control group compound feed; SV-vaccinated piglets fed with control group compound feed; RFnonV-non-vaccinated piglets fed with fermented compound feed; RFV-vaccinated piglets fed with fermented compound feed. Samples from 10 animals per group were collected at the beginning and end of the experiment. Metagenomic analysis showed that fermentation had a positive impact on the Lactobacillus prevalence during the post-weaning period of pigs, and vaccination had no negative impact on microbial communities. Although a higher amount of Lactobacillus was detected in vaccinated, compared with non-vaccinated groups. At the end of experiment, there was a significantly higher LAB count in the faeces of both vaccinated compared to non-vaccinated groups (26.6% for SV and 17.2% for RFV), with the highest LAB count in the SV group. At the end of experiment, the SV faeces also had the highest total bacteria count (TBC). The RFV group had a 13.2% increase in total enterobacteria count (TEC) at the end of experiment, and the SV group showed a 31.2% higher yeast/mould (Y/M) count. There were no significant differences in the average daily gain (ADG) among the groups; however, there were significant differences in the feed conversion ratios (FCR) between several groups: SV vs. SnonV (11.5% lower in the SV group), RFV vs. RFnonV (10.2% lower in the RFnonV group) and SV vs. RFV (21.6% lower in the SV group). Furthermore, there was a significant, very strong positive correlation between FCR and TEC in piglets' faeces (R = 0.919, p = 0.041). The lowest ammonia emission was in RFV group section (58.2, 23.8, and 47.33% lower compared with the SnonV, SV and RFnonV groups, respectively). Notably, there was lower ammonia emission in vaccinated groups (45.2% lower in SV vs. SnonV and 47.33% lower in RFV vs. RFnonV). There was also a significant, very strong positive correlation between ammonia emission and Y/M count in piglets' faeces at the end of the experiment (R = 0.974; p = 0.013). Vaccination as a separate factor did not significantly influence piglets' blood parameters. Overall, by changing from an extruded soya to cheaper rapeseed meal and applying the fermentation model with the selected LAB combination, it is possible to feed piglets without any undesirable changes in health and growth performance in a more sustainable manner. However, to evaluate the influence of vaccination and its interaction with other parameters (feed, piglets' age, breed, etc.) on piglets' parameters, additional studies should be performed and methods should be standardised to ensure the results may be compared.
Collapse
|
14
|
Song S, Park GN, Choe S, Cha RM, Kim SY, Hyun BH, Park BK, An DJ. Genetic Diversity of Porcine Circovirus Isolated from Korean Wild Boars. Pathogens 2020; 9:pathogens9060457. [PMID: 32526932 PMCID: PMC7350290 DOI: 10.3390/pathogens9060457] [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: 04/28/2020] [Revised: 06/07/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
Abstract
In Korea, three genotypes of porcine circovirus type 2 (PCV2a, PCV2b, and PCV2d) have been identified on domestic pig farms, while two genotypes (PCV2a and PCV2b) have been identified in wild boar populations. Here, we investigated genotype diversity and genotypic shift in 91 PCV2 isolates from 1340 wild boars captured in South Korea between 2013 and 2017. Phylogenetic analyses based on the complete ORF2 showed that the 91 PCV2 strains were detected as four genotypes by qPCR screening assay: PCV2a (2.2%, 2/91), PCV2b (16.5%, 15/91), PCV2d (80.2%, 73/91), and PCV2h (1.1%, 1/91). Only one intergenotype recombinant event was detected between PCV2 ORF2 in wild boars (PCV2b) and domestic pigs (PCV2a). Amino acid positions 86–89 within ORF2, which distinguishes the different genotypes, were conserved in all PCV2 genotypes isolated from South Korean wild boars, including TNKI in PCV2a/PCV2h, SNPR in PCV2b, and SNPL in PCV2d. The estimated nucleotide substitution rates in the ORF2 region of viruses from South Korean wild boars and domestic pigs were 5.8145 × 10−4 and 4.5838 × 10−4 substitutions per site per year (s/s/y), respectively. The times to the most recent common ancestor (tMRCA) for South Korean domestic pig PCV2 were 1937 (PCV2a), 1972 (PCV2b), 1999 (PCV2d-1), and 2000 (PCV2d-2). By contrast, the tMRCA for South Korean wild boar PCV2b and PCV2d were 1989 and 2001, respectively. Thus, the PCV2d genotype is prevalent among South Korean wild boars and domestic pigs.
Collapse
Affiliation(s)
- Sok Song
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - Gyu-Nam Park
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - SeEun Choe
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - Ra Mi Cha
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - Song-Yi Kim
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - Bang-Hun Hyun
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
| | - Bong-Kyun Park
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
- College of Veterinary Medicine, Seoul University, Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
| | - Dong-Jun An
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimchen, Gyeongbuk-do 39660, Korea; (S.S.); (G.-N.P.); (S.C.); (R.M.C.); (S.-Y.K.); (B.-H.H.); (B.-K.P.)
- Correspondence: ; Tel.: +82-54-912-0795
| |
Collapse
|
15
|
Jiang Z, Wu J, Jiang M, Xie Y, Bu W, Liu C, Zhang G, Luo M. A Novel Technique for Constructing Infectious Cloning of Type 3 Porcine Circovirus. Front Microbiol 2020; 11:1067. [PMID: 32582064 PMCID: PMC7296095 DOI: 10.3389/fmicb.2020.01067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/29/2020] [Indexed: 11/17/2022] Open
Abstract
Porcine circovirus type 3 (PCV3), which currently lacks effective preventive measures, has caused tremendous economic losses to the pig husbandry. Obtaining the strain of PCV3 is the key to preparing related vaccines and developing corresponding antiviral drugs. In this study, according to the linear sequence of PCV3 DNA published on GenBank, the sequence was rearranged with SnapGene gene-editing software, and after rearrangement, the HindIII restriction endonuclease site was added to the end of the linear DNA, so that both ends have the same restriction endonuclease site. On this basis, the rearranged linear DNA is obtained by gene synthesis, PCR amplification, DNA purification, etc., and is digested and connected in vitro to obtain cyclized DNA. PCV3 infectious clones were obtained by transfecting 3D4/21 cell lines. The obtained PCV3 was identified by PCR, Western blotting, and indirect immunofluorescence tests. The results showed that this study successfully obtained the strain of PCV3 in vitro. To further evaluate the pathogenicity of the obtained PCV3 infectious clones, this study established an animal model of Kunming mice infected with PCV3. The results of RT-PCR, Western blotting and immunohistochemistry showed that PCV3 can infect myocardium and alveoli of Kunming mice, but no PCV3 was detected in other tissues. The above studies indicate that PCV3 circular DNA can be used to construct PCV3 infectious clones. This research will provide a new method for the construction of circular DNA viruses and lay the foundation for the research and pathogenesis of PCV3 vaccine.
Collapse
Affiliation(s)
- Zaixue Jiang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jiajun Wu
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Mei Jiang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yilun Xie
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Wandi Bu
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Canbin Liu
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Guihong Zhang
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Manlin Luo
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| |
Collapse
|
16
|
Ouyang T, Zhang X, Liu X, Ren L. Co-Infection of Swine with Porcine Circovirus Type 2 and Other Swine Viruses. Viruses 2019; 11:v11020185. [PMID: 30795620 PMCID: PMC6410029 DOI: 10.3390/v11020185] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 02/18/2019] [Accepted: 02/21/2019] [Indexed: 12/21/2022] Open
Abstract
Porcine circovirus 2 (PCV2) is the etiological agent that causes porcine circovirus diseases and porcine circovirus-associated diseases (PCVD/PCVAD), which are present in every major swine-producing country in the world. PCV2 infections may downregulate the host immune system and enhance the infection and replication of other pathogens. However, the exact mechanisms of PCVD/PCVAD are currently unknown. To date, many studies have reported that several cofactors, such as other swine viruses or bacteria, vaccination failure, and stress or crowding, in combination with PCV2, lead to PCVD/PCVAD. Among these cofactors, co-infection of PCV2 with other viruses, such as porcine reproductive and respiratory syndrome virus, porcine parvovirus, swine influenza virus and classical swine fever virus have been widely studied for decades. In this review, we focus on the current state of knowledge regarding swine co-infection with different PCV2 genotypes or strains, as well as with PCV2 and other swine viruses.
Collapse
Affiliation(s)
- Ting Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Xinwei Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Xiaohua Liu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
| | - Linzhu Ren
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, 5333 Xi'an Road, Changchun 130062, China.
- College of Life Sciences, Shandong Normal University, Jinan 250014, China.
| |
Collapse
|
17
|
Jäckel S, Muluneh A, Pöhle D, Ulber C, Dähnert L, Vina-Rodriguez A, Groschup MH, Eiden M. Co-infection of pigs with Hepatitis E and porcine circovirus 2, Saxony 2016. Res Vet Sci 2018; 123:35-38. [PMID: 30583230 DOI: 10.1016/j.rvsc.2018.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/17/2018] [Accepted: 12/17/2018] [Indexed: 11/16/2022]
Abstract
Hepatitis E virus (HEV) is a recognized zoonotic disease; autochthonous infections in Europe are caused to a great extent by HEV genotype 3. Pigs and wild boar are the main reservoirs for this genotype and normally they develop no or only subclinical symptoms with mild histopathological lesions. However, co-infections with other pig pathogens can lead to severe cases in pigs, including liver hemorrhage and necrosis. During a monitoring program 2016 in Saxony, Germany, farmed pigs with various clinical outcomes including fatalities were analysed for HEV and concurrent infections. We could detect eight HEV infected pigs from which six were co-infected with porcine circovirus 2 (PCV2). Phylogenetic analysis revealed HEV sub-genotypes 3e and 3f as well as PCV2 genotypes 2b and 2d. A direct correlation of the co-infection to the course of disease could not be determined, but the results provide hints that the immune modulatory effects of PCV2 combined with HEV influence the disease pattern in pigs.
Collapse
Affiliation(s)
- Susanne Jäckel
- Saxon State Laboratory of Health and Veterinary Affairs, Jägerstraße 8/10, 01099 Dresden, Germany
| | - Aemero Muluneh
- Saxon State Laboratory of Health and Veterinary Affairs, Jägerstraße 8/10, 01099 Dresden, Germany
| | - Dietrich Pöhle
- Saxon State Laboratory of Health and Veterinary Affairs, Jägerstraße 8/10, 01099 Dresden, Germany
| | - Claudia Ulber
- Saxon State Laboratory of Health and Veterinary Affairs, Jägerstraße 8/10, 01099 Dresden, Germany
| | - Lisa Dähnert
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Ariel Vina-Rodriguez
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Martin H Groschup
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Martin Eiden
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany.
| |
Collapse
|
18
|
Afolabi KO, Iweriebor BC, Obi CL, Okoh AI. Genetic characterization and diversity of porcine circovirus type 2 in non-vaccinated South African swine herds. Transbound Emerg Dis 2018; 66:412-421. [PMID: 30291727 DOI: 10.1111/tbed.13036] [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] [Received: 02/21/2018] [Revised: 07/14/2018] [Accepted: 09/27/2018] [Indexed: 02/01/2023]
Abstract
The porcine circovirus type 2 (PCV2) is a swine infectious viral pathogen of great significance in global swine herds. It was recently detected at another Province of South Africa sequel to the first detection of North American-like strain (PCV2a) at Gauteng about two decades ago, but there is a dearth of information about the genomic features and diversity of the viral strains in circulation within the country and the entire sub-Saharan Africa region. To date, only one complete genome of the virus from South Africa is available on global data base. This current effort is therefore geared towards the full-genome characterization of the circulating PCV2 strains in the pigs of Eastern Cape Province. With the use of conventional polymerase chain reaction method, fifteen complete PCV2 genomes were successfully amplified, sequenced and assembled from field samples obtained from non-vaccinated pigs in the region. Neighbor Joining and Maximum Likelihood phylogenetic analyses of the ORF2 gene and full genomes unanimously showed that most of the assembled genomes (11) belong to genotype PCV2b. Furthermore, three of the characterized sequences formed clade with other reference mutant PCV2b and PCV2b subtype 1C (i.e. PCV2d) strains from the USA, China and South Korea. The last sequence, however, clustered with other reference strains belonging to PCV2 intermediate clade 2 (PCV2-IM2), recently identified in a global PCV2 strains phylogenetic analysis. This study reports the first complete genome sequences of PCV2b, PCV2d and PCV2-IM2 in pigs from South Africa, and it gives a possible insight into the genetic characteristics and variability of the viral strains presently in circulation within the country. It further emphasizes the need for more stringent measures in curtailing the introduction and spread of transboundary swine pathogens in the country and entire Southern African region.
Collapse
Affiliation(s)
- Kayode Olayinka Afolabi
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, Eastern Cape, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, Eastern Cape, South Africa
| | - Benson Chuks Iweriebor
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, Eastern Cape, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, Eastern Cape, South Africa
| | - Chikwelu Lawrence Obi
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, Eastern Cape, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, Eastern Cape, South Africa
| | - Anthony Ifeanyi Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, Eastern Cape, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, Eastern Cape, South Africa
| |
Collapse
|
19
|
Wang D, Zhang S, Zou Y, Yu W, Jiang Y, Zhan Y, Wang N, Dong Y, Yang Y. Structure-Based Design of Porcine Circovirus Type 2 Chimeric VLPs (cVLPs) Displays Foreign Peptides on the Capsid Surface. Front Cell Infect Microbiol 2018; 8:232. [PMID: 30038901 PMCID: PMC6046401 DOI: 10.3389/fcimb.2018.00232] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/19/2018] [Indexed: 11/13/2022] Open
Abstract
Although porcine circovirus-like particles can function as a vector to carry foreign peptides into host cells, displaying foreign peptides on the surface of virus-like particles (VLPs) remains challenging. In this study, a plateau, consisting of the middle portion of Loop CD (MP-Lcd) from two neighboring subunits of PCV2 capsid protein (Cap), was identified as an ideal site to insert various foreign peptides or epitopes and display them on the surface of PCV2 VLPs. One of the goals of this work is to determine if the surface pattern of this plateau can be altered without compromising the neutralizing activity against PCV2 infections. Therefore, biological roles of MP-Lcd regarding VLPs assembly, cell entry, and antigenicity were investigated to determine whether this was a universal site for insertion of foreign functional peptides. Three-dimensional (3D) structure simulations and mutation assays revealed MP-Lcd was dispensable for PCV2 Cap assembly into VLPs and their entry into host cells. Notably, substitution of MP-Lcd with a foreign peptide, caused surface pattern changes around two-fold axes of PCV2 VLPs based on 3D structure simulation, but was not detrimental to VLPs assembly and cell entry. Moreover, this substitution had no adverse effect on eliciting neutralizing antibodies (NAbs) against PCV2 infection in pigs. In conclusion, MP-Lcd of the PCV2 Cap was a promising site to accommodate and display foreign epitopes or functional peptides on the surface of PCV2 VLPs. Furthermore, chimeric VLPs (cVLPs) would have potential as bivalent or multivalent vaccines and carriers to deliver functional peptides to target cells.
Collapse
Affiliation(s)
- Dongliang Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Sujiao Zhang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yawen Zou
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Wanting Yu
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yifan Jiang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yang Zhan
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Naidong Wang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Yanpeng Dong
- Jiangsu Nannong Hi-Tech Co., Ltd, Jiangyin, China
| | - Yi Yang
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Laboratory of Functional Proteomics, Research Center of Reverse Vaccinology, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| |
Collapse
|
20
|
Gan F, Zhou Y, Qian G, Huang D, Hou L, Liu D, Chen X, Wang T, Jiang P, Lei X, Huang K. PCV2 infection aggravates ochratoxin A-induced nephrotoxicity via autophagy involving p38 signaling pathway in vivo and in vitro. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:656-662. [PMID: 29614475 DOI: 10.1016/j.envpol.2018.03.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 03/02/2018] [Accepted: 03/11/2018] [Indexed: 06/08/2023]
Abstract
Ochratoxin A (OTA) is reported to induce nephrotoxicity in animals and humans. Porcine circovirus type 2 (PCV2) could induce porcine dermatitis and nephropathy syndrome. To date, little is known whether virus infection aggravates mycotoxin-induced toxicity. This work aimed to study the effects of PCV2 infection on OTA-induced nephrotoxicity and its mechanism in vivo and vitro. The results in vivo showed that PCV2 infection aggravated OTA-induced poor growth performance, nephrotoxicity, p38 phosphorylation and autophagy as demonstrated by Atg5, LC3 II and p62 protein expressions in kidney of pigs. The results in vitro indicated that PCV2 infection significantly aggravated OTA-induced nephrotoxicity as demonstrated by cell viabilities, annexin V/PI binding and caspase 3 activities, and induced p38 phosphorylation and autophagy in PK15 cells. p38 inhibitor decreased Atg5 and LC3 protein expression induced by PCV2 infection and OTA combined treatment. Adding autophagy inhibitor 3-MA or CQ alleviated the aggravating effects of PCV2 infection on OTA-induced nephrotoxicity. Atg5-specific siRNA eliminated the aggravating effects of PCV2 infection on OTA-induced nephrotoxicity. Taken together, these data indicate that in vivo and in vitro PCV2 infection aggravated OTA-induced nephrotoxicity via p38-mediated autophagy.
Collapse
Affiliation(s)
- Fang Gan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Yajiao Zhou
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Gang Qian
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Da Huang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Lili Hou
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Dandan Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Xingxiang Chen
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Tian Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Ping Jiang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Xingen Lei
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
| | - Kehe Huang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China.
| |
Collapse
|
21
|
Cruz TF, Magro AJ, de Castro AMMG, Pedraza-Ordoñez FJ, Tsunemi MH, Perahia D, Araujo JP. In vitro and in silico studies reveal capsid-mutant Porcine circovirus 2b with novel cytopathogenic and structural characteristics. Virus Res 2018; 251:22-33. [PMID: 29730308 DOI: 10.1016/j.virusres.2018.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Abstract
Porcine circovirus 2 (PCV2) is an icosahedral, non-enveloped, and single-stranded circular DNA virus that belongs to the family Circoviridae, genus Circovirus, and is responsible for a complex of different diseases defined as porcine circovirus diseases (PCVDs). These diseases - including postweaning multisystemic wasting syndrome (PMWS), enteric disease, respiratory disease, porcine dermatitis and nephropathy syndrome (PDNS), and reproductive failure - are responsible for large economic losses in the pig industry. After serial passages in swine testicle (ST) cells of a wild-type virus isolated from an animal with PMWS, we identified three PCV2b viruses with capsid protein (known as Cap protein) cumulative mutations, including two novel mutants. The mutant viruses were introduced into new ST cell cultures for reisolation and showed, in comparison to the wild-type PCV2b, remarkable viral replication efficiency (> 1011 DNA copies/ml) and cell death via necrosis, which were clearly related to the accretion of capsid protein mutations. The analysis of a Cap protein/capsid model showed that the mutated residues were located in solvent-accessible positions on the external PCV2b surface. Additionally, the mutated residues were found in linear epitopes and participated in pockets on the capsid surface, indicating that these residues could also be involved in antibody recognition. Taking into account the likely natural emergence of PCV2b variants, it is possible to consider that the results of this work increase knowledge of Circovirus biology and could help to prevent future serious cases of vaccine failure that could lead to heavy losses to the swine industry.
Collapse
Affiliation(s)
- Taís Fukuta Cruz
- Departamento de Microbiologia e Imunologia, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
| | - Angelo José Magro
- Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Departamento de Bioprocessos e Biotecnologia, Faculdade de Ciências Agronômicas (FCA), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
| | - Alessandra M M G de Castro
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade de São Paulo (USP), São Paulo, São Paulo, Brazil
| | | | - Miriam Harumi Tsunemi
- Departamento de Bioestatística, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil
| | - David Perahia
- Laboratoire de Biologie et de Pharmacologie Appliquée, ENS Cachan/Université Paris-Saclay, Cachan, France.
| | - João Pessoa Araujo
- Departamento de Microbiologia e Imunologia, Instituto de Biociências (IB), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil; Instituto de Biotecnologia (IBTEC), Universidade Estadual Paulista (Unesp), Botucatu, São Paulo, Brazil.
| |
Collapse
|
22
|
Ouyang T, Liu X, Ouyang H, Ren L. Mouse models of porcine circovirus 2 infection. Animal Model Exp Med 2018; 1:23-28. [PMID: 30891543 PMCID: PMC6357427 DOI: 10.1002/ame2.12009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/16/2018] [Indexed: 12/23/2022] Open
Abstract
PCV2 is considered the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases (PCVD/PCVAD). However, the exact mechanism underlying PCVD/PCVAD is currently unknown. Mouse models of PCV2 are valuable experimental tools that can shed light on the pathogenesis of infection and will enable the evaluation of antiviral agents and vaccine candidates. In this review, we discuss the current state of knowledge of mouse models used in PCV2 research that has been performed to date, highlighting their strengths and limitations, as well as prospects for future PCV2 studies.
Collapse
Affiliation(s)
- Ting Ouyang
- Science and Technology Innovation Center for Animal Genome Editing of Jilin ProvinceCollege of Animal SciencesJilin UniversityChangchunJilinChina
| | - Xiao‐hui Liu
- Science and Technology Innovation Center for Animal Genome Editing of Jilin ProvinceCollege of Animal SciencesJilin UniversityChangchunJilinChina
| | - Hong‐sheng Ouyang
- Science and Technology Innovation Center for Animal Genome Editing of Jilin ProvinceCollege of Animal SciencesJilin UniversityChangchunJilinChina
| | - Lin‐zhu Ren
- Science and Technology Innovation Center for Animal Genome Editing of Jilin ProvinceCollege of Animal SciencesJilin UniversityChangchunJilinChina
| |
Collapse
|
23
|
Afolabi KO, Iweriebor BC, Obi LC, Okoh AI. Molecular detection of Porcine circovirus type 2 in swine herds of Eastern Cape Province South Africa. BMC Microbiol 2017; 17:212. [PMID: 29096613 PMCID: PMC5669008 DOI: 10.1186/s12866-017-1121-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 10/23/2017] [Indexed: 12/18/2022] Open
Abstract
Background Porcine circovirus type 2 (PCV2) remains the main causative viral pathogen of porcine circovirus-associated diseases (PCVAD) of great economic importance in pig industry globally. This present study aims at determining the occurrence of the viral pathogen in swine herds of the Province. Results The data obtained revealed that 15.93% of the screened samples (54/339) from the swine herds of the studied areas were positive for PCV2; while the severity of occurrence of the viral pathogen as observed at farm level ranges from approximately 5.6 to 60% in the studied farms. The majority (15 out of 17 = 88%) of the analyzed sequences were found clustering with other PCV2b strains in the phylogenetic analysis. More interestingly, two other sequences obtained were also found clustering within PCV2d genogroup, which is presently another fast-spreading genotype with observable higher virulence in global swine herds. Conclusion This is the first report of PCV2 in swine herds of the Province and the first detection of PCV2b and PCV2d in South African swine herds. It follows the first reported case of PCV2a in an outbreak of porcine multisystemic wasting syndrome (PMWS) in Gauteng Province, South Africa more than one decade ago. This finding confirmed the presence of this all-important viral pathogen in pigs of the region; which could result in a serious outbreak of PCVAD and huge economic loss at the instances of triggering factors if no appropriate measures are taken to effectively curb its spread. Electronic supplementary material The online version of this article (10.1186/s12866-017-1121-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kayode Olayinka Afolabi
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa. .,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa.
| | - Benson Chuks Iweriebor
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa
| | - Larry Chikwelu Obi
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa.,Academic and Research Division, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, South Africa
| | - Anthony Ifeanyi Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape Province, 5700, South Africa
| |
Collapse
|
24
|
Global Status of Porcine circovirus Type 2 and Its Associated Diseases in Sub-Saharan Africa. Adv Virol 2017; 2017:6807964. [PMID: 28386278 PMCID: PMC5366187 DOI: 10.1155/2017/6807964] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/13/2017] [Accepted: 02/23/2017] [Indexed: 12/27/2022] Open
Abstract
Globally, Porcine circovirus type 2 (PCV2) is a recognized viral pathogen of great economic value in pig farming. It is the major cause of ravaging postweaning multisystemic wasting syndrome (PMWS) and many other disease syndromes generally regarded as Porcine circovirus associated diseases (PCVAD) in Europe. PCV2 infections, specifically PMWS, had impacted huge economic loss on swine production at different regions of the world. It has been studied and reported at different parts of the globe including: North and South America, Europe, Asia, Oceania, Middle East, and the Caribbean. However, till date, this virus and its associated diseases have been grossly understudied in sub-Sahara African region and the entire continent at large. Two out of forty-nine, representing just about 4% of countries that make up sub-Sahara Africa presently, have limited records on reported cases and occurrence of the viral pathogen despite the ubiquitous nature of the virus. This review presents an overview of the discovery of Porcine circovirus and its associated diseases in global pig herds and emphasizes the latest trends in PCV2 vaccines and antiviral drugs development and the information gaps that exist on the occurrence of this important viral pathogen in swine herds of sub-Saharan Africa countries. This will serve as wake-up call for immediate and relevant actions by stakeholders in the region.
Collapse
|
25
|
Evidence of natural co-infection with PCV2b subtypes in vivo. Arch Virol 2017; 162:2015-2020. [PMID: 28260141 DOI: 10.1007/s00705-017-3303-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/05/2017] [Indexed: 01/04/2023]
Abstract
Porcine circovirus type 2 (PCV2) is the causative pathogen of porcine circovirus-associated diseases (PCVAD). This virus evolves mostly through point mutations and genome recombination between different PCV2 genotypes (e.g. PCV2a and PCV2b), as has been confirmed in swine herds. In the current work, the complete PCV2 genome sequences of 69 clones derived from various tissues (lymph node, spleen and lung,) of an infected individual, were subjected to phylogenetic and alignment analyses. The results not only demonstrate co-infection with distinct PCV2b subtypes (e.g. 1B and 1C) in the same animal, but also highlight another mechanism of evolution - diverse point mutations acquired during immune evasion by this virus.
Collapse
|
26
|
Genotypic diversity of porcine circovirus type 2 (PCV2) and genotype shift to PCV2d in Korean pig population. Virus Res 2017; 228:24-29. [DOI: 10.1016/j.virusres.2016.11.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 11/23/2022]
|
27
|
Wang N, Zhan Y, Wang A, Zhang L, Khayat R, Yang Y. In silico analysis of surface structure variation of PCV2 capsid resulting from loop mutations of its capsid protein (Cap). J Gen Virol 2016; 97:3331-3344. [PMID: 27902320 DOI: 10.1099/jgv.0.000634] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Outbreaks of porcine circovirus (PCV) type 2 (PCV2)-associated diseases have caused substantial economic losses worldwide in the last 20 years. The PCV capsid protein (Cap) is the sole structural protein and main antigenic determinant of this virus. In this study, not only were phylogenetic trees reconstructed, but variations of surface structure of the PCV capsid were analysed in the course of evolution. Unique surface patterns of the icosahedral fivefold axes of the PCV2 capsid were identified and characterized, all of which were absent in PCV type 1 (PCV1). Icosahedral fivefold axes, decorated with Loops BC, HI and DE, were distinctly different between PCV2 and PCV1. Loops BC, determining the outermost surface around the fivefold axes of PCV capsids, had limited homology between Caps of PCV1 and PCV2. A conserved tyrosine phosphorylation motif in Loop HI that might be recognized by non-receptor tyrosine kinase(s) in vivo was present only in PCV2. Particularly, the concurrent presence of 60 pairs of the conserved tyrosine and a canonical PXXP motif on the PCV2 capsid surface could be a mechanism for PXXP motif binding to and activation of an SH3-domain-containing tyrosine kinase in host cells. Additionally, a conserved cysteine in Loop DE of the PCV2 Cap was substituted by an arginine in PCV1, indicating potentially distinct assembly mechanisms of the capsid in vitro between PCV1 and PCV2. Therefore, these unique patterns on the PCV2 capsid surface, absent in PCV1 isolates, might be related to cell entry, virus function and pathogenesis.
Collapse
Affiliation(s)
- Naidong Wang
- Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan, PR China
| | - Yang Zhan
- Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan, PR China
| | - Aibing Wang
- Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan, PR China
| | | | - Reza Khayat
- Department of Chemistry, City College of New York, NY, USA
- PhD Programs in Biochemistry and Chemistry, The Graduate Center, City University of New York, NY, USA
| | - Yi Yang
- Laboratory of Functional Proteomics (LFP) and Research Center of Reverse Vaccinology (RCRV), College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan, PR China
| |
Collapse
|
28
|
Ren L, Chen X, Ouyang H. Interactions of porcine circovirus 2 with its hosts. Virus Genes 2016; 52:437-44. [DOI: 10.1007/s11262-016-1326-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/19/2016] [Indexed: 12/11/2022]
|
29
|
Zhan Y, Wang N, Zhu Z, Wang Z, Wang A, Deng Z, Yang Y. In silico analyses of antigenicity and surface structure variation of an emerging porcine circovirus genotype 2b mutant, prevalent in southern China from 2013 to 2015. J Gen Virol 2016; 97:922-933. [PMID: 26758466 DOI: 10.1099/jgv.0.000398] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the pivotal pathogen causing porcine circovirus-associated diseases. In this study, 62 PCV2 isolates were identified from seven farms in southern China from 2013 to 2015 and phylogenetic trees were reconstructed based on whole-genome sequences or the cap gene. In this investigation, PCV2b was the main genotype in circulation throughout these farms. Furthermore, an emerging mutant (PCV2b-1C), isolated from PCV2-vaccinated farms, was the predominant strain prevalent on these farms. In addition, we isolated a new cluster that may represent evolution of the virus through recombination of PCV2b-1A/1B and PCV2b-1C. Finally, we discuss evidence that antigenicity and surface structure variation of the capsid resulted from mutation of the C-terminal loop (Loop CT) of the PCV2b-1C Cap in silico.
Collapse
Affiliation(s)
- Yang Zhan
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Naidong Wang
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Zhe Zhu
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Zhanfeng Wang
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Aibing Wang
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Zhibang Deng
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| | - Yi Yang
- Research Center of Functional Proteomics, College of Veterinary Medicine, Hunan Agricultural University, Changsha, PRChina
| |
Collapse
|
30
|
Zhang D, He K, Wen L, Fan H. Genetic and phylogenetic analysis of a new porcine circovirus type 2 (PCV2) strain in China. Arch Virol 2015; 160:3149-51. [PMID: 26395090 DOI: 10.1007/s00705-015-2615-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/14/2015] [Indexed: 11/26/2022]
Abstract
Porcine circovirus type 2 (PCV2) is the etiological agent associated with several pig diseases that are collectively referred to as porcine circovirus-associated disease (PCVAD). Unfortunately, PCV2 has had a serious economic impact on the swine industry. In this study, we report the genome sequence of a novel PCV2 isolate (JS2015) identified in pigs in Jiang Su, China. The complete DNA sequence was 1766 nucleotides long with an A+T content of 52.7%. It lacked a guanine (G) at nucleotide position 1045 compared to other reference PCV2 strains with a sequence length of 1766 nucleotides. Genetic characterization and phylogenetic analysis showed that the isolate JS2015 was most closely related to members of the PCV2d (AY181946) lineage. Our data provide insight into the epidemiology of porcine circovirus and may facilitate further study of the origin and evolution of PCV2.
Collapse
Affiliation(s)
- Dan Zhang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, 210000, China.
| | - Kongwang He
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, 210000, China.
| | - Libin Wen
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing, 210000, China.
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
31
|
Piñeyro PE, Kenney SP, Giménez-Lirola LG, Heffron CL, Matzinger SR, Opriessnig T, Meng XJ. Expression of antigenic epitopes of porcine reproductive and respiratory syndrome virus (PRRSV) in a modified live-attenuated porcine circovirus type 2 (PCV2) vaccine virus (PCV1-2a) as a potential bivalent vaccine against both PCV2 and PRRSV. Virus Res 2015; 210:154-64. [PMID: 26239318 DOI: 10.1016/j.virusres.2015.07.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 12/01/2022]
Abstract
Co-infection of pigs in the field with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) is common and poses a major concern in effective control of PCV2 and PRRSV. We previously demonstrated that insertion of foreign epitope tags in the C-terminus of PCV2 ORF2 produced infectious virions that elicited humoral immune responses against both PCV2 capsid and inserted epitope tags. In this study, we aimed to determine whether the non-pathogenic chimeric virus PCV1-2a, which is the basis for the licensed PCV2 vaccine Fostera PCV, can express PRRSV antigenic epitopes, thus generating dual immunity as a potential bivalent vaccine against both PCV2 and PPRSV. Four different linear B-cell antigenic epitopes of PRRSV were inserted into the C-terminus of the capsid gene of the PCV1-2a vaccine virus. We showed that insertion of 12 (PRRSV-GP2 epitope II, PRRSV-GP3 epitope I, and PRRSV-GP5 epitope I), and 14 (PRRSV-GP5 epitope IV) amino acid residues did not impair the replication of the resulting PCV1-2a-PRRSVEPI chimeric viruses in vitro. The four chimeric PCV1-2a viruses expressing PRRSV B-cell linear epitopes were successfully rescued and characterized. An immunogenicity study in pigs revealed that two of the four chimeric viruses, PCV1-2a-PRRSVEPIGP3IG and PCV1-2a-PRRSVEPIEPIGP5IV, elicited neutralizing antibodies against PRRSV VR2385 as well as PCV2 (strains PCV2a, PCV2b, and mPCV2b). The results have important implications for exploring the potential use of PCV1-2a vaccine virus as a live virus vector to develop bivalent MLVs against both PCV2 and PRRSV.
Collapse
Affiliation(s)
- Pablo E Piñeyro
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA; Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine, Ames, IA 5001, USA
| | - Scott P Kenney
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Luis G Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine, Ames, IA 5001, USA
| | - C Lynn Heffron
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Shannon R Matzinger
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine, Ames, IA 5001, USA; The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Xiang-Jin Meng
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA.
| |
Collapse
|
32
|
Franzo G, Cortey M, de Castro AMMG, Piovezan U, Szabo MPJ, Drigo M, Segalés J, Richtzenhain LJ. Genetic characterisation of Porcine circovirus type 2 (PCV2) strains from feral pigs in the Brazilian Pantanal: An opportunity to reconstruct the history of PCV2 evolution. Vet Microbiol 2015; 178:158-62. [PMID: 25975522 DOI: 10.1016/j.vetmic.2015.05.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
Abstract
Since its discovery, Porcine circovirus type 2 has emerged as one of the most relevant swine infectious diseases, causing relevant economic losses for the pig industry. While four genotypes were identified, only three (PCV2a, PCV2b and PCV2d) are currently circulating and display a worldwide distribution. Another genotype, PCV2c, has been described only once in Danish archive samples collected between 1980 and 1990. In addition to commercial pigs, PCV2 has been demonstrated to infect wild boars and other wild species, which can potentially serve as a reservoir for domestic populations. In this study, eight sequences obtained from feral pigs in the Pantanal region (Mato Grosso do Sul State, Brazil) were compared with reference sequences and other Brazilian sequences, and the results revealed remarkable genetic diversity, with all four genotypes currently recognised being detected (PCV2a, PCV2b, PCV2c and PCV2d). This finding represents a remarkable discovery, as it is the first detection of PCV2c since 1990 and the first-ever detection of PCV2c in live animals. The peculiar population history and ecological scenario of feral pigs in the Pantanal coupled with the complex, and still only partially known relationship of feral pigs with other PCV2 susceptible species (i.e., domestic pigs, wild boars and peccaries), open exciting questions concerning PCV2 origin and evolution. Overall, the results of the present study led us to form the following hypothesis: the PCV2 strains found in feral pigs may be the last descent of the strains that circulated among European pigs in the past, or they may have infected these feral pigs more recently through a bridge species.
Collapse
Affiliation(s)
| | | | | | - Ubiratan Piovezan
- Empresa Brasileira de Pesquisa Agropecuária - Embrapa Pantanal, Corumbá, MS, Brazil
| | - Matias Pablo Juan Szabo
- Laboratório de Ixodologia, Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, MG, Brazil
| | | | - Joaquim Segalés
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Departament de Sanitat i d'Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Leonardo José Richtzenhain
- Department of Preventive Veterinary Medicine and Animal Health, College of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil
| |
Collapse
|
33
|
Genetic characterization of porcine circovirus type 2 in the Korean wild boar population. Vet Microbiol 2014; 169:147-53. [PMID: 24480584 DOI: 10.1016/j.vetmic.2013.12.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 12/20/2013] [Accepted: 12/23/2013] [Indexed: 11/23/2022]
Abstract
The porcine circovirus type 2 (PCV2) has reached very high levels in the pig population in South Korea and throughout the world since it was first described in the late 1990s. In this study, we found that the prevalence of PCV2 in the Korean wild boar population was 4.98% (91/1825). Interestingly, 19 PCV2 ORF2 sequences that could be completely sequenced showed that they belonged only to genotype PCV2b, subgroup 1A/B (n=16) and 1C (n=3). We suggest that sites potentially under positive selection are responsible for the antigenicity changes and phenotypic switch patterns in the capsid gene of 55 PCV2s from Korean domestic pigs, but the sites potentially under positive selection in the 19 PCV2 ORF2 genes from Korean wild boar are not responsible for antigenicity.
Collapse
|
34
|
Wang C, Pang VF, Lee F, Liao PC, Huang YL, Lin YL, Lai SS, Jeng CR. Development and evaluation of a loop-mediated isothermal amplification method for rapid detection and differentiation of two genotypes of porcine circovirus type 2. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2013; 47:363-70. [PMID: 23845855 DOI: 10.1016/j.jmii.2013.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 04/19/2013] [Accepted: 05/08/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Porcine circovirus type 2 (PCV2) is one of the major swine viral diseases and has caused significant economic loss to pig producers. PCV2 has been divided into two major genotypes: PCV2a, PCV2b. A loop-mediated isothermal amplification (LAMP) method was developed for the detection and differentiation of PCV2a and PCV2b in clinical samples. METHODS LAMP-specific primer sets were designed based on six PCV2a and six PCV2b reference isolates. To determine the analytical specificity of LAMP, DNA samples extracted from 36 porcine virus isolates were tested by LAMP, including eight PCV2a, 11 PCV2b, four PCV type 1, two porcine parvovirus, three pseudorabies virus, and eight porcine reproductive and respiratory virus. To evaluate the analytical sensitivity of the assay, 10-fold serial dilutions of PCV2a and PCV2b recombinant plasmids were performed to prepare the dilutions at concentration from 10(6) to 1 copy(ies)/μL, and each dilution was tested by both LAMP and nested polymerase chain reaction (nested PCR). A total of 168 clinical samples were analyzed by both LAMP and nested PCR, and the relative sensitivity and specificity of LAMP compared to nested PCR were calculated. RESULTS Using different primer sets of LAMP, LAMP could be completed within 50 minutes. This method was found to be highly analytically specific for PCV2a and PCV2b; only the target gene was detected without cross-reaction. The analytical sensitivity of LAMP for PCV2a and PCV2b were 10 copies/μL, demonstrating analytical sensitivity comparable to that obtained using nested PCR. In addition, the sensitivity and specificity of LAMP relative to those of nested PCR were 97.7% and 100.0%, respectively. The percentage of observed agreement was 98.2%, and the κ statistic was 0.949. CONCLUSION LAMP is a rapid, specific, and sensitive diagnostic method for the detection and differentiation of PCV2a and PCV2b in clinical samples.
Collapse
Affiliation(s)
- Chun Wang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan; Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan
| | - Victor Fei Pang
- Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan
| | - Fan Lee
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Pei-Chih Liao
- Animal Disease Control Centre of Yunlin County, No. 517, Sec. 2, Yunlin Road, Douliou City, Yunlin County 640, Taiwan
| | - Yu-Liang Huang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Yeou-Liang Lin
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Road, Tamsui, New Taipei City 251, Taiwan
| | - Shiow-Suey Lai
- Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan.
| | - Chian-Ren Jeng
- Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan.
| |
Collapse
|
35
|
Wei C, Zhang M, Chen Y, Xie J, Huang Z, Zhu W, Xu T, Cao Z, Zhou P, Su S, Zhang G. Genetic evolution and phylogenetic analysis of porcine circovirus type 2 infections in southern China from 2011 to 2012. INFECTION GENETICS AND EVOLUTION 2013; 17:87-92. [DOI: 10.1016/j.meegid.2013.03.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/13/2013] [Accepted: 03/23/2013] [Indexed: 11/15/2022]
|
36
|
Huynh TML, Nguyen BH, Nguyen VG, Dang HA, Mai TN, Tran THG, Ngo MH, Le VT, Vu TN, Ta TKC, Vo VH, Kim HK, Park BK. Phylogenetic and phylogeographic analyses of porcine circovirus type 2 among pig farms in Vietnam. Transbound Emerg Dis 2013; 61:e25-34. [PMID: 23414511 DOI: 10.1111/tbed.12066] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Indexed: 11/29/2022]
Abstract
This study demonstrated the prevalence of Porcine circovirus type 2 (PCV2) among pig farms in Vietnam. Analyses of the genome, capsid protein and phylogeny classified all 30 Vietnamese PCV2 strains as the PCV2b genotype, belonging to the clusters of 1A, 1B, 1C and recombinant forms. Each viral genome was 1767 nucleotides long and shared 96.0-100% nucleotide sequence identity. The amino acid substitutions in the capsid protein of the Vietnamese PCV2 strains were in immunodominant regions, and the majority of strains (24/30) contained a lysine extension at the C-terminus. Bayesian phylogeographic analysis revealed epidemic links of the PCV2 recombinant cluster within and among countries, which supports a circulating recombinant form of PCV2. Further analysis by the Jameson-Wolf antigenic index indicated antigenic alterations at important sites in the capsid protein (sites 131-133) among the recombinant cluster and the other clusters of PCV2b.
Collapse
Affiliation(s)
- T M L Huynh
- Department of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Hanoi University of Agriculture, Hanoi, Vietnam
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Wang C, Pang VF, Lee F, Huang TS, Lee SH, Lin YJ, Lin YL, Lai SS, Jeng CR. Prevalence and genetic variation of porcine circovirus type 2 in Taiwan from 2001 to 2011. Res Vet Sci 2012; 94:789-95. [PMID: 23260863 DOI: 10.1016/j.rvsc.2012.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 11/22/2012] [Accepted: 11/26/2012] [Indexed: 11/26/2022]
Abstract
Porcine circovirus type 2 (PCV2) is the major causative agent of postweaning multisystemic wasting syndrome (PMWS) in Taiwanese pig farms. We analyzed the complete genomes of 571 Taiwanese PCV2 isolates in Taiwan from 2001 to 2011 and divided the isolates into 2 distinct genotypes (PCV2a and PCV2b) with 6 clusters (1A, 1B, 1C, 2B, 2D, and 2E). Of the 571 Taiwanese PCV2 isolates, 22.9% (131/571) belonged to PCV2a and 77.1% (440/571) to PCV2b. In this study, PCV2a isolates were the most common in 2001, and then PCV2b isolates became predominate thereafter and widely distributed in pig farms since 2003. Sequence comparisons among the 571 isolates indicated that 89.6-100% had nucleotide identity for complete genome and 87.3-100% for open reading frames 2 (ORF2). The results suggest that a higher genetic variation and shift occurred among PCV2 isolates collected from 2001 to 2011 in Taiwan.
Collapse
Affiliation(s)
- Chun Wang
- Animal Health Research Institute, Council of Agriculture, Executive Yuan, No. 376, Chung-Cheng Rd., Tansui, New Taipei City 251, Taiwan, ROC
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Complete genome sequence of a novel field strain of rearranged porcine circovirus type 2 in southern China. J Virol 2012; 86:10895. [PMID: 22966188 DOI: 10.1128/jvi.01817-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report here the complete genomic sequence of a novel porcine circovirus type 2 (PCV2) strain, which is supposed to be the result of natural genetic recombination between the ORF1 gene of genotype PCV2b-1B and the ORF2 gene of PCV2b-1C. Further analyses revealed that this novel PCV2 strain arose from recombination between PCV2a and PCV2b strains within the ORF2 gene. To our knowledge, this is the first report of both inter- and intragenotype PCV2 gene rearrangement in the field, and it will help in understanding the epidemiology and molecular characteristics of porcine circovirus type 2(PCV2) in southern China.
Collapse
|
39
|
Castro AMMG, Castro FG, Budiño FEL, Baldin CM, Silva SOS, Brandão PE, Richtzenhain LJ. Detection of Genetic characterization of Porcine circovirus 2 (PCV2) in Brazilian wildlife boars. Braz J Microbiol 2012; 43:1022-5. [PMID: 24031922 PMCID: PMC3768886 DOI: 10.1590/s1517-838220120003000025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 08/24/2011] [Accepted: 06/07/2012] [Indexed: 11/25/2022] Open
Abstract
A semi-intensive wildlife boars farm presented a clinical history of high mortality in 70 – 90 days-old pigs (> 50 %). Two 90 days-old animals with weight loss and wasting were necropsied and the samples tested for PCV2 by polymerase chain reaction (PCR). The genetic material of PCV2 was sequenced and classified into the PCV2a genotype together with PCV2 sequences obtained from samples of Poland, Brazil, Slovenia and Greece wild boars.
Collapse
Affiliation(s)
- A M M G Castro
- Departamento de Medicina Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo , São Paulo, SP , Brasil
| | | | | | | | | | | | | |
Collapse
|
40
|
de Castro AMMG, Cruz TF, Salgado VR, Kanashiro TM, Ferrari KL, Araujo JP, Brandão PE, Richtzenhain LJ. Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of São Paulo, Brazil. Acta Vet Scand 2012; 54:29. [PMID: 22554105 PMCID: PMC3434114 DOI: 10.1186/1751-0147-54-29] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 05/03/2012] [Indexed: 11/10/2022] Open
Abstract
Background Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms. Findings Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10). Conclusions The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.
Collapse
|
41
|
Cadar D, Cságola A, Lőrincz M, Tombácz K, Spînu M, Tuboly T. Detection of natural inter- and intra-genotype recombination events revealed by cap gene analysis and decreasing prevalence of PCV2 in wild boars. INFECTION GENETICS AND EVOLUTION 2012; 12:420-7. [DOI: 10.1016/j.meegid.2012.01.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 01/12/2012] [Accepted: 01/14/2012] [Indexed: 11/16/2022]
|
42
|
Epidemiology and transmission of porcine circovirus type 2 (PCV2). Virus Res 2012; 164:78-89. [DOI: 10.1016/j.virusres.2011.12.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 11/25/2011] [Accepted: 12/01/2011] [Indexed: 12/11/2022]
|
43
|
Population dynamics and ORF3 gene evolution of porcine circovirus type 2 circulating in Korea. Arch Virol 2012; 157:799-810. [DOI: 10.1007/s00705-012-1234-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 12/14/2011] [Indexed: 11/26/2022]
|
44
|
CHIOU MT, LIN CN, YANG CY, SU GS, LIN CF, CHANG TC. Genotypic Change and Phylogenetic Analysis of Porcine Circovirus Type 2 in Taiwanese Pig Herds. J Vet Med Sci 2012; 74:1303-10. [DOI: 10.1292/jvms.12-0044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Ming-Tang CHIOU
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung 912, Taiwan, ROC
| | - Chao-Nan LIN
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung 912, Taiwan, ROC
| | - Cheng-Yao YANG
- Division of Animal Medicine, Animal Technology Institute Taiwan, Chunan, Miaoli 350, Taiwan, ROC
| | - Guan-Shiuan SU
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung 912, Taiwan, ROC
| | - Chuen-Fu LIN
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan, ROC
| | - Tsung-Chou CHANG
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung 912, Taiwan, ROC
| |
Collapse
|
45
|
Vidigal PMP, Mafra CL, Silva FMF, Fietto JLR, Silva Júnior A, Almeida MR. Tripping over emerging pathogens around the world: a phylogeographical approach for determining the epidemiology of Porcine circovirus-2 (PCV-2), considering global trading. Virus Res 2011; 163:320-7. [PMID: 22056846 DOI: 10.1016/j.virusres.2011.10.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 10/17/2011] [Accepted: 10/20/2011] [Indexed: 11/26/2022]
Abstract
Porcine circovirus-2 (PCV-2) is an emerging virus associated with a number of different syndromes in pigs known as Porcine Circovirus Associated Diseases (PCVAD). Since its identification and characterization in the early 1990s, PCV-2 has achieved a worldwide distribution, becoming endemic in most pig-producing countries, and is currently considered as the main cause of losses on pig farms. In this study, we analyzed the main routes of the spread of PCV-2 between pig-producing countries using phylogenetic and phylogeographical approaches. A search for PCV-2 genome sequences in GenBank was performed, and the 420 PCV-2 sequences obtained were grouped into haplotypes (group of sequences that showed 100% identity), based on the infinite sites model of genome evolution. A phylogenetic hypothesis was inferred by Bayesian Inference for the classification of viral strains and a haplotype network was constructed by Median Joining to predict the geographical distribution of and genealogical relationships between haplotypes. In order to establish an epidemiological and economic context in these analyses, we considered all information about PCV-2 sequences available in GenBank, including papers published on viral isolation, and live pig trading statistics available on the UN Comtrade database (http://comtrade.un.org/). In these analyses, we identified a strong correlation between the means of PCV-2 dispersal predicted by the haplotype network and the statistics on the international trading of live pigs. This correlation provides a new perspective on the epidemiology of PCV-2, highlighting the importance of the movement of animals around the world in the emergence of new pathogens, and showing the need for effective sanitary barriers when trading live animals.
Collapse
Affiliation(s)
- Pedro M P Vidigal
- Molecular Animal Infectology Laboratory, Institute of Applied Biotechnology to Agriculture (BIOAGRO), Federal University of Vicosa, Vicosa 36570-000, Brazil
| | | | | | | | | | | |
Collapse
|
46
|
Beach NM, Meng XJ. Efficacy and future prospects of commercially available and experimental vaccines against porcine circovirus type 2 (PCV2). Virus Res 2011; 164:33-42. [PMID: 22005075 DOI: 10.1016/j.virusres.2011.09.041] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 09/30/2011] [Accepted: 09/30/2011] [Indexed: 01/14/2023]
Abstract
Porcine circovirus type 2 (PCV2) is the causative agent of an economically significant collection of disease syndromes in pigs, now known as porcine circovirus associated diseases (PCVADs) in the United States or porcine circovirus diseases (PCVDs) in Europe. Inactivated and subunit vaccines based on PCV2a genotype are commercially available and have been shown to be effective at decreasing mortality and increasing growth parameters in commercial swine herds. Since 2003, there has been a drastic global shift in the predominant prevalence of PCV2b genotype in swine populations, concurrently in most but not all cases with increased severity of clinical disease. Although the current commercial vaccines based on PCV2a do confer cross-protection against PCV2b, novel experimental vaccines based on PCV2b genotype such as modified live-attenuated vaccines are being developed and may provide a superior protection and reduce vaccine costs. In this review, we discuss the current understanding of the impact of PCV2 infection on the host immune response, review the efficacy of the currently available commercial PCV2 vaccines in experimental and field conditions, and provide insight into novel experimental approaches that are useful in the development of next generation vaccines against PCV2.
Collapse
Affiliation(s)
- Nathan M Beach
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0913, USA
| | | |
Collapse
|
47
|
Jaganathan S, Toung OP, Yee PL, Yew TD, Yoon CP, Keong LB. Genetic characterization of porcine circovirus 2 found in Malaysia. Virol J 2011; 8:437. [PMID: 21914166 PMCID: PMC3184107 DOI: 10.1186/1743-422x-8-437] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 09/13/2011] [Indexed: 11/23/2022] Open
Abstract
Background Porcine circovirus type 2 is the primary etiological agent associated with a group of complex multi-factorial diseases classified as Porcine Circovirus Associated Diseases (PCVAD). Sporadic cases reported in Malaysia in 2007 caused major economic losses to the 2.2 billion Malaysian ringgit (MYR) (approximately 0.7 billion US dollar) swine industry. The objective of the present study was to determine the association between the presence of PCV2 and occurrences of PCVAD. Results This study showed that 37 out of 42 farms sampled were positive for PCV2 using PCR screening. Thirteen whole genome of PCV2 isolates from pigs with typical PCVAD symptoms were successfully sequenced. These isolates shared 98.3-99.2% similarities with sequences of isolates from the Netherlands. All thirteen isolates fell into the same clade as PCV2b isolates from other countries. Amino acid sequence analysis of the putative capsid protein (ORF2) of the PCV2 revealed that there are three clusters found in Malaysia, namely cluster 1C and 1A/1B. Of interest, three of the isolates (isolates Mal 005, Mal 006 and Mal 010) had a proline substitution for arginine or isoleucine encoded at nt. position 88-89. Eight of the isolates had mutations at the C terminus of the putative capsid protein suggestive of higher pathogenicity which may account for the high reports of PCVAD clinical symptoms in 2007. Conclusion Phylogenetic study suggests that there may be a link between movements of animals by import of breeders into the country being the route of entry of the virus. While it is not possible to eradicate the virus from commercial pigs, the swine industry in Malaysia can be safeguarded by control measures implemented throughout the country. These measures should include improved biosecurity, disease surveillance; vaccination as well as enforcement of regulations formulated to control and prevent the spread of this disease on a national scale.
Collapse
Affiliation(s)
- Seetha Jaganathan
- Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
| | | | | | | | | | | |
Collapse
|
48
|
Jantafong T, Boonsoongnern A, Poolperm P, Urairong K, Lekcharoensuk C, Lekcharoensuk P. Genetic characterization of porcine circovirus type 2 in piglets from PMWS-affected and -negative farms in Thailand. Virol J 2011; 8:88. [PMID: 21356069 PMCID: PMC3058092 DOI: 10.1186/1743-422x-8-88] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 02/28/2011] [Indexed: 11/23/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the major swine pathogen associated with Porcine circovirus associated disease (PCVAD) including post-weaning multisystemic wasting syndrome (PMWS). Currently, there are 4 subtypes of PCV2 (PCV2a, b, c and d) and some epidemiological evidences demonstrated that virulence of PCV2 may relate to its subtypes. Recently, PMWS was observed more frequently in swine farms in Thailand; however, the information regarding to PCV2 subtype involved was limited. Therefore, this study was aimed to determine the association between occurrence of PMWS and PCV2 subtypes as well as genetically characterize PCV2 in Thailand. PCV2 DNA was isolated from faecal swabs and whole blood of piglets from PMWS-affected and -negative farms. The full length ORF2 sequences were compared using multiple alignment. The results showed that PCV2 DNA was detected more frequently in PMWS-affected farms. The nucleotide identities of the ORF2 from 9 PCV2 isolates representing each PMWS-affected farm and one from the negative farm ranged from 92.4 to 99.5% suggesting that there is some genetic variation of PCV2 in Thai swine. The 10 PCV2 isolates were classified into 2 clusters, in which the 7 isolates from PMWS-positive farms were in PCV2b cluster 1 A/B. The remaining isolates were separated in the new subtype called PCV2e. The results suggest the presence of new PCV2 subtypes in addition to PCV2a and PCV2b in Asian swine population. However, correlation between subtypes and virulence of PCV2 infection is not conclusive due to limited number of the PCV2 sequences from PMWS negative farms.
Collapse
Affiliation(s)
- Tippawan Jantafong
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Thailand
| | | | | | | | | | | |
Collapse
|
49
|
Beach NM, Ramamoorthy S, Opriessnig T, Wu SQ, Meng XJ. Novel chimeric porcine circovirus (PCV) with the capsid gene of the emerging PCV2b subtype cloned in the genomic backbone of the non-pathogenic PCV1 is attenuated in vivo and induces protective and cross-protective immunity against PCV2b and PCV2a subtypes in pigs. Vaccine 2010; 29:221-32. [DOI: 10.1016/j.vaccine.2010.10.050] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 10/14/2010] [Accepted: 10/20/2010] [Indexed: 01/15/2023]
|
50
|
Abstract
AbstractPorcine circovirus type 2 (PCV2) is a small, non-enveloped, circular, single-stranded DNA virus of economic importance in the swine industry worldwide. Based on the sequence analyses of PCV2 strains, isolates can be divided into five subtypes (PCV2a–e). PCV2 is an ubiquitous virus based on serological and viremia data from countries worldwide. In addition, PCV2 DNA was discovered in archived samples prior to the first recognition of clinical disease. Recently, a worldwide shift in PCV2 subtype from PCV2a to PCV2b occurred. PCV2 DNA can be detected in fecal, nasal, oral and tonsillar swabs as well as in urine and feces from both naturally and experimentally infected pigs. PCV2 DNA can be detected early in the infectious process and persists for extended periods of time. The effectiveness of disinfectants for reducing PCV2in vitrois variable and PCV2 is very stable in the pig environment. Limited data exist on the horizontal transmission of PCV2. Direct transmission of PCV2 between experimentally or naturally infected animals and naïve animals has been documented and the incorporation of clinical or subclinically infected animals into a population represents a risk to the herd. Indirect transmission through the oral, aerosol or vaccine routes is likely a lesser risk for the transmission of PCV2 in most swine populations but may be worth evaluating in high heath herds. The objective of this review was to discuss data on the epidemiology and horizontal transmission of PCV2.
Collapse
|