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Rapid detection of porcine circovirus type 2 by a red latex microsphere immunochromatographic strip. Appl Microbiol Biotechnol 2022; 106:5757-5769. [PMID: 35945364 PMCID: PMC9363268 DOI: 10.1007/s00253-022-12074-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/01/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022]
Abstract
Abstract To establish a rapid and specific antigen detection method for porcine circovirus type 2 (PCV2), monoclonal antibodies (mAbs) were produced against the PCV2 epidemic strains and a red latex microsphere immunochromatographic strip was established. A total of eight anti-PCV2b and four anti-PCV2d mAbs were produced, and seven mAbs were confirmed to react with PCV2a, PCV2b, and PCV2d strains using an immunoperoxidase monolayer assay. The results of micro-neutralization tests showed that the mAbs 2C8, 9H4, 10G7, 7B9, and 7C7 had good neutralizing activity, whereas the neutralizing activity of the mAbs 4B3, 4C9, 6H9, and 7E2 was lower than 50%. Three mAbs, 4B3, 7C7, and 9H4, and PCV2 pAb were selected for the establishment of a red latex microsphere immunochromatographic strip, and the combination of mAb 7C7 labeled with red latex microspheres and mAb 9H4 exhibited the greatest detection ability. The immunochromatographic strip had minimum detection limits of 102.5 TCID50/0.1 ml, 100.7 TCID50/0.1 ml, and 101.5 TCID50/0.1 ml for PCV2a/CL, PCV2b/MDJ, and PCV2d/LNHC, respectively. Furthermore, no cross-reactivity was found for African swine fever virus, classical swine fever virus, porcine respiratory and reproductive syndrome virus, porcine parvovirus, porcine pseudorabies virus, porcine circovirus type 1, transmissible gastroenteritis virus, porcine epidemic diarrhea virus, porcine rotavirus, or porcine deltacoronavirus using the immunochromatographic strip. Using PCR as a reference standard, the detection sensitivity, specificity, and overall coincidence rate of the immunochromatographic strip were 81.13%, 100%, and 90.00%. Additionally, the detection ability of the immunochromatographic strip was correlated with that of virus titration. The immunochromatographic strip was used to detect 183 clinical disease samples, and the average positive detection rate was 22.95%. In summary, this method has good sensitivity and specificity and is simple, convenient, and quick to operate. It has high application value for on-site diagnosis of PCV2 and virus quantification. Key points • A red latex microsphere immunochromatographic strip for PCV2 detection was developed. • The method was not only simple to operate, but also takes less time. • The method had good sensitivity and specificity.
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Zhai SL, Lu SS, Wei WK, Lv DH, Wen XH, Zhai Q, Chen QL, Sun YW, Xi Y. Reservoirs of Porcine Circoviruses: A Mini Review. Front Vet Sci 2019; 6:319. [PMID: 31616677 PMCID: PMC6763682 DOI: 10.3389/fvets.2019.00319] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 09/05/2019] [Indexed: 01/01/2023] Open
Abstract
Porcine circovirus (PCV) is one of the smallest known DNA viruses in mammals. At present, PCVs are divided into three species, PCV1, PCV2, and PCV3. PCV1 and PCV2 were found in the 1970s and the 1990s, respectively, whereas PCV3 was discovered recently in 2016. PCV1 does not cause diseases in pigs. However, PCV3, similar to PCV2, is reported to be associated with several swine diseases, including porcine dermatitis and nephropathy syndrome (PDNS) and reproductive failure. PCVs are very common in domestic pigs as well as wild boars. However, PCVs have been occasionally isolated from non-porcine animals, including ruminants (such as cattle, goats, wild chamois, and roe deers), rodents (such as NMRI mice, BALB/c mice, Black C57 mice, ICR mice, Mus musculus, and Rattus rattus), canines (such as dogs, minks, foxes, and raccoon dogs), insects (such as flies, mosquitoes, and ticks), and shellfish. Moreover, PCVs are frequently reported in biological products, including human vaccines, animal vaccines, porcine-derived commercial pepsin products, and many cell lines. PCVs are also abundant in the environment, including water samples and air samples. Interestingly, PCV1 and/or PCV2 antibody or antigen has also been detected in sera, stool samples and respiratory swab samples of human, revealing zoonotic potential of PCVs. Thus, PCVs inhabit many types of reservoirs. In this review, we summarize the reservoirs of PCVs, and this information would be helpful in understanding the natural circulating status and possible cross-species transmission of PCVs.
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Affiliation(s)
- Shao-Lun Zhai
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Shou-Sheng Lu
- Guangdong Center for Animal Disease Prevention and Control, Guangzhou, China
| | - Wen-Kang Wei
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Dian-Hong Lv
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Xiao-Hui Wen
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Qi Zhai
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Qin-Ling Chen
- Key Laboratory of Animal Disease Prevention of Guangdong Province, Animal Disease Diagnostic Center, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Techniques of Guangdong Province, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Yan-Wei Sun
- Guangdong Center for Animal Disease Prevention and Control, Guangzhou, China
| | - Yun Xi
- Department of Clinical Laboratory, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
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Wei R, Xie J, Theuns S, Nauwynck HJ. Changes on the viral capsid surface during the evolution of porcine circovirus type 2 (PCV2) from 2009 till 2018 may lead to a better receptor binding. Virus Evol 2019; 5:vez026. [PMID: 31392030 PMCID: PMC6676070 DOI: 10.1093/ve/vez026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases (PCVAD). Three major PCV2 genotypes (PCV2a, PCV2b, and PCV2d) have been identified globally. Despite their worldwide distribution, the prevalence and genetic evolution of PCV2 in Belgium has not previously been determined. In this study, 319 samples from animals suffering from diseases likely to be associated with PCV2 were collected from 2009 to 2018 and analysed by virus titration. The overall prevalence of PCV2 in PCVAD-suspected cases was 15.7 per cent (50/319). The phylogenetic analysis demonstrated that at least three genotypes (PCV2a, PCV2b, and PCV2d) circulated in Belgium from 2009 till 2018, and that PCV2 evolved from PCV2a to PCV2b and from PCV2d-1 to PCV2d-2. Sequence comparison among the forty-three PCV2 isolates showed that they had 89.7–100 per cent nucleotide-sequence and 88.5–100 per cent amino-acid-sequence identities. Three amino acid sites were under positive selection. Three-dimensional analysis of genotype-specific amino acids revealed that most of the mutations were on the outside of the cap protein with a few conserved mutations present on the inner side. Mutations toward more basic amino acids were found on the upper and tail parts of two connecting capsid proteins which form one big contact region, most probably involved in receptor binding. The lower part was relatively conserved. This polarity change together with the formation of an extruding part drive the virus to a more efficient GAG receptor binding. Taken together, these results showed a genotype shift from PCV2a to PCV2b and later on from PCV2d-1 to PCV2d-2, and a PCV2 evolution toward a better receptor binding capacity.
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Affiliation(s)
- Ruifang Wei
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Jiexiong Xie
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Sebastiaan Theuns
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Hans J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
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Human cells are permissive for the productive infection of porcine circovirus type 2 in vitro. Sci Rep 2019; 9:5638. [PMID: 30948762 PMCID: PMC6449348 DOI: 10.1038/s41598-019-42210-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/27/2019] [Indexed: 11/19/2022] Open
Abstract
Porcine circovirus 2 (PCV2) is the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases, which are widespread in swine-producing countries. However, there is controversy regarding the susceptibility of human cells to PCV2 infection. In this study, human cell lines were infected with PCV2 and blind passaged several times. PCV2 entered and replicated in human cells, and infectious virions were generated, indicating that human cell lines were permissive to PCV2 replication. Furthermore, PCV2 replication in human cell lines was enhanced by D-glucosamine or concanavalin A (ConA). However, the infection efficiency of PCV2 was lower in human cells than in PK-15 cells, suggesting that PCV2 infection was limited in human cells. Our study reveals that human cells are permissive for the productive infection of porcine circovirus type 2 in vitro.
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Karuppannan AK, Opriessnig T. Possible risks posed by single-stranded DNA viruses of pigs associated with xenotransplantation. Xenotransplantation 2018; 25:e12453. [PMID: 30264878 PMCID: PMC6120555 DOI: 10.1111/xen.12453] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/12/2018] [Accepted: 07/20/2018] [Indexed: 12/11/2022]
Abstract
Routine large-scale xenotransplantation from pigs to humans is getting closer to clinical reality owing to several state-of-the-art technologies, especially the ability to rapidly engineer genetically defined pigs. However, using pig organs in humans poses risks including unwanted cross-species transfer of viruses and adaption of these pig viruses to the human organ recipient. Recent developments in the field of virology, including the advent of metagenomic techniques to characterize entire viromes, have led to the identification of a plethora of viruses in many niches. Single-stranded DNA (ssDNA) viruses are the largest group prevalent in virome studies in mammals. Specifically, the ssDNA viral genomes are characterized by a high rate of nucleotide substitution, which confers a proclivity to adapt to new hosts and cross-species barriers. Pig-associated ssDNA viruses include torque teno sus viruses (TTSuV) in the Anelloviridae family, porcine parvoviruses (PPV), and porcine bocaviruses (PBoV) both in the family of Parvoviridae, and porcine circoviruses (PCV) in the Circoviridae family, some of which have been confirmed to be pathogenic to pigs. The risks of these viruses for the human recipient during xenotransplantation procedures are relatively unknown. Based on the scant knowledge available on the prevalence, predilection, and pathogenicity of pig-associated ssDNA viruses, careful screening and monitoring are required. In the case of positive identification, risk assessments and strategies to eliminate these viruses in xenotransplantation pig stock may be needed.
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Affiliation(s)
- Anbu K. Karuppannan
- Department of Veterinary Diagnostic and Production Animal MedicineCollege of Veterinary MedicineIowa State UniversityAmesIowa
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal MedicineCollege of Veterinary MedicineIowa State UniversityAmesIowa
- The Roslin Institute and The Royal (Dick) School of Veterinary StudiesUniversity of EdinburghRoslinMidlothianUK
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Cao L, Sun W, Lu H, Tian M, Xie C, Zhao G, Han J, Wang W, Zheng M, Du R, Jin N, Qian A. Genetic variation analysis of PCV1 strains isolated from Guangxi Province of China in 2015. BMC Vet Res 2018; 14:43. [PMID: 29415728 PMCID: PMC5803923 DOI: 10.1186/s12917-018-1345-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/14/2018] [Indexed: 12/11/2022] Open
Abstract
Background Porcine circovirus type 1 (PCV1) was discovered in 1974 as a contaminant of a porcine kidney (PK-15) cell line and was generally accepted to be nonpathogenic. But recently it was shown to cause lesions in experimentally infected pig fetuses. Serological evidence and genetic studies suggested that PCV1 was widespread in domestic pigs. Thus, the molecular epidemiology and genetic variation of PCV1 are still necessary to understand. Results Here 247 tissue samples were collected from piglets in Guangxi Province, China and performed whole-genome sequencing of the PCV1 genome. Thirteen PCV1 strains were sequenced from the samples. Similarity analysis showed that there were 97.8% to 99.6% nucleotide similarity to each other and 97.1% to 99.8% nucleotide similarity to the 40 reference strains. Besides, based on sequence analysis, we found one putative recombinant virus named GXdx84 strain contained the open-reading frame 1 (ORF1) of PCV1 and the ORF2 of PCV2d-2, which was consistent with the results of phylogenetic analysis that compared PCV1 and PCV2 strains. Variation analysis of the amino acids of the capsid protein revealed that the GXyl224 strain, which encoded 235 amino acids, had two amino acids more than other strains. This is the first study to report that a cap gene mutation resulted in lengthening of in the gene sequence. Conclusions These data contribute to the understanding of PCV1 evolution and molecular epidemiology that will facilitate programs for its control and prevention.
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Affiliation(s)
- Liang Cao
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, People's Republic of China.,Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Wenchao Sun
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Huijun Lu
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Mingyao Tian
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Changzhan Xie
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, People's Republic of China.,Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Guanyu Zhao
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China.,College of Veterinary Medicine, Jilin University, Changchun, 130062, People's Republic of China
| | - Jicheng Han
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Wei Wang
- Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China
| | - Min Zheng
- Guangxi Center for Animal Disease Control and Prevention, Nanning, 530001, People's Republic of China
| | - Rui Du
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
| | - Ningyi Jin
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, People's Republic of China. .,Institute of Military Veterinary, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Academy of Military Sciences, Changchun, 130122, People's Republic of China.
| | - Aidong Qian
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
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Bao RM, Shibuya A, Uehira T, Sato T, Urayama T, Sakai K, Yunoki M. Successful removal of porcine circovirus-1 from immunoglobulin G formulated in glycine solution using nanofiltration. Biologicals 2018; 51:32-36. [DOI: 10.1016/j.biologicals.2017.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/27/2017] [Accepted: 10/22/2017] [Indexed: 10/18/2022] Open
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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.
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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
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Effect of dietary selenium yeast supplementation on porcine circovirus type 2 (PCV2) infections in mice. PLoS One 2015; 10:e0115833. [PMID: 25723390 PMCID: PMC4344303 DOI: 10.1371/journal.pone.0115833] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/27/2014] [Indexed: 11/19/2022] Open
Abstract
The present study was performed to determine the protective role of dietary selenium (Se) yeast supplementation in porcine circovirus type 2 (PCV2) infected mice. Forty-eight Kun Ming female mice were randomly assigned to Se yeast group (0.3%Se +basal diet, n = 24) and control group (basal diet, n = 24). After 3 days of adaptive feeding and 15 days treatment with the experimental feed, mice were challenged by intraperitioneal injection of PCV2 at the dosage of 2000 TCID50 (50% tissue culture infection dose, TCID50). Serum total superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and interleukin-1 beta (IL-1β) levels were measured at 5, 10, 15, 20 days post infection (dpi). The PCV2 virus load in the liver, spleen and lung, and the microscopic lesions in the liver, spleen and lung also were determined on 5, 10, 15, and 20 dpi. Dietary Se yeast supplementation decreased (Pμ0.05) the serum levels of TNF-α, but had no significant effect on the activity of SOD and the levels of MDA, CRP and IL-1β between experimental and control groups. Dietary Se yeast supplementation had little effect on the PCV2 virus load in the liver, spleen and lung. However, mice in the selenium yeast group showed a significant decrease in microscopic lesion scores in the lung and spleen compared with those in the control group (Pμ0.05). These data indicate Se yeast attenuated the PCV2 infection through altering the systemic inflammation and maintaining the normal organ morphology.
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Zhai SL, Chen SN, Xu ZH, Tang MH, Wang FG, Li XJ, Sun BB, Deng SF, Hu J, Lv DH, Wen XH, Yuan J, Luo ML, Wei WK. Porcine circovirus type 2 in China: an update on and insights to its prevalence and control. Virol J 2014; 11:88. [PMID: 24885983 PMCID: PMC4031328 DOI: 10.1186/1743-422x-11-88] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 05/01/2014] [Indexed: 12/30/2022] Open
Abstract
Currently, porcine circovirus type 2 (PCV2) is considered the major pathogen of porcine circovirus associated-diseases (PCVAD) that causes large economic losses for the swine industry in the world annually, including China. Since the first report of PCV2 in 1998, it has been drawing tremendous attention for the government, farming enterprises, farmers, and veterinary practitioners. Chinese researchers have conducted a number of molecular epidemiological work on PCV2 by molecular approaches in the past several years, which has resulted in the identification of novel PCV2 genotypes and PCV2-like agents as well as the description of new prevalence patterns. Since late 2009, commercial PCV2 vaccines, including the subunit vaccines and inactivated vaccines, have already been used in Chinese swine farms. The aim of this review is to update the insights into the prevalence and control of PCV2 in China, which would contribute to understanding the epidemiology, control measures and design of novel vaccines for PCV2.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Man-Lin Luo
- College of Veterinary Medicine, South China Agricultural University, No, 483 Wushan Road, Tianhe District, Guangzhou 510642, China.
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Yang B, Wang H, Ho C, Lester P, Chen Q, Neske F, Baylis SA, Blümel J. Porcine circovirus (PCV) removal by Q sepharose fast flow chromatography. Biotechnol Prog 2013; 29:1464-71. [PMID: 24039195 PMCID: PMC4158902 DOI: 10.1002/btpr.1804] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 08/15/2013] [Indexed: 12/04/2022]
Abstract
The recently discovered contamination of oral rotavirus vaccines led to exposure of millions of infants to porcine circovirus (PCV). PCV was not detected by conventional virus screening tests. Regulatory agencies expect exclusion of adventitious viruses from biological products. Therefore, methods for inactivation/removal of viruses have to be implemented as an additional safety barrier whenever feasible. However, inactivation or removal of PCV is difficult. PCV is highly resistant to widely used physicochemical inactivation procedures. Circoviruses such as PCV are the smallest viruses known and are not expected to be effectively removed by currently-used virus filters due to the small size of the circovirus particles. Anion exchange chromatography such as Q Sepharose(®) Fast Flow (QSFF) has been shown to effectively remove a range of viruses including parvoviruses. In this study, we investigated PCV1 removal by virus filtration and by QSFF chromatography. As expected, PCV1 could not be effectively removed by virus filtration. However, PCV1 could be effectively removed by QSFF as used during the purification of monoclonal antibodies (mAbs) and a log10 reduction value (LRV) of 4.12 was obtained.
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Affiliation(s)
- Bin Yang
- Purification Development, Genentech, Inc., One DNA Way, South San Francisco, CA, 94080
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Hua T, Wang X, Bai J, Zhang L, Liu J, Jiang P. Attenuation of porcine circovirus type-2b by replacement with the Rep gene of porcine circovirus type-1. Virus Res 2013; 173:270-9. [PMID: 23454919 DOI: 10.1016/j.virusres.2013.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/18/2013] [Accepted: 02/18/2013] [Indexed: 10/27/2022]
Abstract
Porcine circovirus type-2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases and has 4 main ORFs, ORF1 (Rep gene), ORF2 (Cap gene), ORF3 within ORF1, and ORF4, which is overlapped with ORF3, and 1 origin (Ori) of replication located between ORF1 and ORF2. The chimeric PCV1-2, containing the PCV2 capsid, PCV1 rep, and Ori genes, is attenuated in pigs. In order to verify the role of the Rep gene or Ori in the virulence of PCV2, 3 chimeric viruses [PCV2b-Ori1 (PCV1 Ori gene cloned into the backbone of PCV2b), PCV2b-rep1 (PCV1 Rep gene cloned into the backbone of PCV2b), and PCV2b-rep1-Ori1 (PCV1 Rep and Ori genes cloned into the backbone of PCV2b)] and 2 wild-type recombinant PCV2b and PCV1 were constructed and identified. The experimental results in piglets showed that clinical symptoms, viremia, viral load, lesions in lymphoid and lung tissues, and IL-10 and TNF-α expression levels in PBMCs in the PCV2b-rep1-Ori1 and PCV2b-rep1 groups were significantly decreased, compared to PCV2-infected piglets. Meanwhile, histological lesions of lymphoid and lung tissues, viral loads in lymphoid tissues, viremia, and TNF-α expression in PBMCs were not significantly different between groups PCV2b-Ori1 and PCV2b, suggesting that the Rep gene (ORF1) likely contributes to viral pathogenicity in vivo.
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Affiliation(s)
- Tao Hua
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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Abstract
In the past two decades or so, a number of viruses have emerged in the global swine population. Some, such as porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2), cause economically important diseases in pigs, whereas others such as porcine torque teno virus (TTV), now known as Torque teno sus virus (TTSuV), porcine bocavirus (PBoV) and related novel parvoviruses, porcine kobuvirus, porcine toroviruses (PToV) and porcine lymphotropic herpesviruses (PLHV), are mostly subclinical in swine herds. Although some emerging swine viruses such as swine hepatitis E virus (swine HEV), porcine endogenous retrovirus (PERV) and porcine sapovirus (porcine SaV) may have a limited clinical implication in swine health, they do pose a potential public health concern in humans due to zoonotic (swine HEV) or potential zoonotic (porcine SaV) and xenozoonotic (PERV, PLHV) risks. Other emerging viruses such as Nipah virus, Bungowannah virus and Menangle virus not only cause diseases in pigs but some also pose important zoonotic threat to humans. This article focuses on emerging and re-emerging swine viruses that have a limited or uncertain clinical and economic impact on pig health. The transmission, epidemiology and pathogenic potential of these viruses are discussed. In addition, the two economically important emerging viruses, PRRSV and PCV2, are also briefly discussed to identify important knowledge gaps.
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Affiliation(s)
- X J Meng
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA.
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Cortey M, Segalés J. Low levels of diversity among genomes of Porcine circovirus type 1 (PCV1) points to differential adaptive selection between Porcine circoviruses. Virology 2012; 422:161-4. [DOI: 10.1016/j.virol.2011.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/10/2011] [Accepted: 10/12/2011] [Indexed: 11/27/2022]
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15
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Kumar D, Beach NM, Meng XJ, Hegde NR. Use of PCR-based assays for the detection of the adventitious agent porcine circovirus type 1 (PCV1) in vaccines, and for confirming the identity of cell substrates and viruses used in vaccine production. J Virol Methods 2011; 179:201-11. [PMID: 22079617 DOI: 10.1016/j.jviromet.2011.10.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 10/18/2011] [Accepted: 10/27/2011] [Indexed: 11/25/2022]
Abstract
Safety and quality are important issues for vaccines. Whereas reversion to virulence poses a safety risk with live attenuated vaccines, the potential for the presence of adventitious agents is also an issue of vaccine quality. The recent detection or porcine circovirus type 1 (PCV1) in human vaccines has further highlighted the importance of quality control in vaccine production. The purpose of this study was to use a novel conventional PCR to detect PCV1, and subsequently screen materials used in the manufacture of vaccines at Bharat Biotech International Limited, India. The genome or gene fragments of PCV1 were not detected in any of the vaccines and materials tested, including the live attenuated rotavirus vaccine candidate ROTAVAC(®). Further, the identity of the cells and the viruses used as starting materials in the manufacture of these vaccines was confirmed by species-specific PCR or virus-specific RT-PCR, and no cross-contamination was detected in any case. The methods can be applied for regular in-house quality control screening of raw materials and seeds/banks, as well as formulated vaccines.
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Affiliation(s)
- Deepak Kumar
- Ella Foundation, Genome Valley, Turkapally, Shameerpet Mandal, Hyderabad 500078, India
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Prickett JR, Johnson J, Murtaugh MP, Puvanendiran S, Wang C, Zimmerman JJ, Opriessnig T. Prolonged Detection of PCV2 and Anti-PCV2 Antibody in Oral Fluids Following Experimental Inoculation. Transbound Emerg Dis 2011; 58:121-7. [DOI: 10.1111/j.1865-1682.2010.01189.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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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]
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18
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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.
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Baylis SA, Finsterbusch T, Bannert N, Blümel J, Mankertz A. Analysis of porcine circovirus type 1 detected in Rotarix vaccine. Vaccine 2010; 29:690-7. [PMID: 21093497 DOI: 10.1016/j.vaccine.2010.11.028] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 11/10/2010] [Accepted: 11/10/2010] [Indexed: 12/01/2022]
Abstract
A metagenomic analysis of live human vaccines has recently demonstrated the presence of porcine circovirus type 1 (PCV1) DNA in the paediatric vaccine Rotarix used in the prevention of acute gastroenteritis. Using real-time PCR for PCV1, titres of PCV1 DNA in several batches of Rotarix were found to be in the order of 6-7 log(10) copies per dose. Pre-treatment of the reconstituted vaccine with the nuclease Benzonase, followed by extraction of nucleic acid and quantification of PCV1 DNA by real-time PCR, revealed that there was no loss of PCV1 DNA titre compared to untreated controls, suggesting that the porcine viral DNA was present in the vaccine in an encapsidated form. PCV1 permissive PS cells, human HEK293 and Vero cells, used for vaccine production, were infected with Rotarix or PCV1, respectively, and subjected to immune fluorescence and RT-PCR. Viral genomes were present in Rotarix-incubated as well as PCV1-infected cells, while viral transcription was seen only in PCV1-infected cells. Similarly, PCV1-specific protein expression was observed in PCV1-infected cells, but not in cells treated with Rotarix. Passaging of the supernatant indicated productive infection in PCV1-infected PS cells, but not in HEK293 and Vero cells or in any cell line incubated with Rotarix. PCV1 DNA present in Rotarix was protected from Benzonase digestion; however, PCV1 was not recognized in immune electron microscopy and unable to infect PS, HEK293 or Vero cells, suggesting that the high amount of PCV1 DNA present in Rotarix does not reflect a corresponding proportion of biologically active virus particles.
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Affiliation(s)
- Sally A Baylis
- Viral Safety Section, Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, D-63225 Langen, Germany.
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Opriessnig T, Prickett JR, Madson DM, Shen HG, Juhan NM, Pogranichniy RR, Meng XJ, Halbur PG. Porcine circovirus type 2 (PCV2)-infection and re-inoculation with homologous or heterologous strains: virological, serological, pathological and clinical effects in growing pigs. Vet Res 2010; 41:31. [PMID: 20167193 PMCID: PMC2826091 DOI: 10.1051/vetres/2010003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 01/13/2010] [Indexed: 12/23/2022] Open
Abstract
Long-term PCV2 infection and/or concurrent infection with genotypes PCV2a and PCV2b may play a role in the development of clinical porcine circovirus-associated disease (PCVAD). To evaluate this premise, 24 11-week-old specific pathogen-free (SPF) pigs were randomly assigned to 1 of 4 treatments: negative controls, a single inoculation with PCV2a, single inoculation followed by re-inoculation with a homologous PCV2a strain, or repeated inoculations with heterologous strains (PCV2a, PCV2b). Pigs were evaluated for clinical signs daily through 140 days post inoculation (dpi). Serum samples were collected every other day from dpi 0 through 14 and weekly thereafter. PCV2-inoculated pigs were viremic by dpi 2 and 13 of 18 pigs remained viremic at 140 dpi. No statistical differences in the onset, level, or duration of PCV2 viremia were detected among treatment groups. Anti-PCV2 antibodies were detected between 14 and 28 dpi and were present through 140 dpi without statistical differences in antibody response among treatment groups. In the current study, pigs had extended viremia combined with detectable tissue PCV2 antigen levels despite the presence of high levels of anti-PCV2 antibody; however, no clinical disease was observed.
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Affiliation(s)
- Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011, USA.
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Kekarainen T, Martínez-Guinó L, Segalés J. Swine torque teno virus detection in pig commercial vaccines, enzymes for laboratory use and human drugs containing components of porcine origin. J Gen Virol 2009; 90:648-653. [DOI: 10.1099/vir.0.006841-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Torque teno viruses (TTVs) are vertebrate infecting, single-stranded circular DNA viruses. Two genetically distinct TTV genogroups (TTV1 and TTV2) infect swine worldwide with high prevalence. Currently, swine TTVs are considered non-pathogenic, although TTV2 has been linked to post-weaning multisystemic wasting syndrome, a porcine circovirus disease. On the other hand, pig materials are an important source of components used in porcine vaccine manufacturing, human drugs and commercial enzyme products. However, there is little information about the possible existence of extraneous viruses in products containing porcine-derived components. In the present study, 26 commercial swine vaccines, seven human drugs and three enzyme products from porcine origin were tested for the presence of TTV1 and TTV2 genomes by PCR. Four vaccines against Mycoplasma hyopneumoniae were positive for TTV2 by PCR. Three M. hyopneumoniae, one porcine parvovirus and one porcine reproductive and respiratory syndrome virus vaccines were PCR positive for TTV1. One human drug contained TTV1 DNA as well as a trypsin enzyme; a porcine-derived elastase product was positive for both TTV genogroups. These results show that swine TTVs are contaminants not only of swine vaccines but also of human drugs containing porcine components and enzymes for laboratory use.
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Affiliation(s)
- Tuija Kekarainen
- Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Laura Martínez-Guinó
- Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Joaquim Segalés
- Departament de Sanitat i d'Anatomia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
- Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Krakowka S, Ringler SS, Arumugam P, McKillen J, McIntosh K, Hartunian C, Hamberg A, Rings M, Allan G, Ellis JA. Evaluation ofMycoplasma hyopneumoniaebacterins for porcine torque teno virus DNAs. Am J Vet Res 2008; 69:1601-7. [DOI: 10.2460/ajvr.69.12.1601] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Porcine circovirus type 2 (PCV2) is the primary causative agent for porcine circovirus-associated disease (PCVAD). PCVAD has been the cause of considerable economic losses to the pork industry worldwide. The disease is primarily characterized by wasting, enlarged lymph nodes, jaundice and weight loss in affected weanling pigs. Several other complex syndromes involving reproductive failure, enteritis, pneumonia and necrotizing dermatitis have also been associated with PCV2 infection. Lymphoid depletion, which is the hallmark lesion of PCVAD, predisposes the host to immunosuppression. Disease progression is further complicated by co-infections with other bacterial and viral pathogens. Despite the availability of effective vaccines for the last 2 years, newly emerging strains of the virus have been reported to cause more severe outbreaks in parts of the USA and Canada. While knowledge of the biology and pathogenesis of PCV2 has progressed considerably over the last 12 years since the disease was recognized, many questions still remain to be answered.
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24
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Cságola A, Kiss I, Tuboly T. Detection and analysis of porcine circovirus type 1 in Hungarian wild boars: short communication. Acta Vet Hung 2008; 56:139-44. [PMID: 18401965 DOI: 10.1556/avet.56.2008.1.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Porcine circovirus type 1 (PCV1) is considered to be a non-pathogenic virus detected in cell cultures, vaccines or products used for cell culture preparations, all of them of porcine origin. Serological evidence and genetic studies suggested that PCV1 was widespread in domestic pigs. The presence of PCV1 in wild boars in Germany was also described using serological methods. This paper reports the first detection of PCV1 in Hungarian wild boars. Samples were collected at slaughterhouses and processed for polymerase chain reactions. The complete genome of PCV1 detected in the samples was determined and compared with the available PCV1 sequences of the GenBank database. The genomes formed two distinct clusters with minimum differences, where the Hungarian wild boar PCV1 (WB-H8) grouped together with genomes originating from domestic swine from China and Australia and with a genome detected in a porcine pepsin product.
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Affiliation(s)
- Attila Cságola
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science H-1143 Budapest Hungária krt. 23-25 Hungary
| | - István Kiss
- 2 Central Agricultural Office Department of Microbiology, Veterinary Diagnostic Directorate Debrecen Hungary
| | - Tamás Tuboly
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science H-1143 Budapest Hungária krt. 23-25 Hungary
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25
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Opriessnig T, Meng XJ, Halbur PG. Porcine circovirus type 2 associated disease: update on current terminology, clinical manifestations, pathogenesis, diagnosis, and intervention strategies. J Vet Diagn Invest 2008; 19:591-615. [PMID: 17998548 DOI: 10.1177/104063870701900601] [Citation(s) in RCA: 449] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Porcine circovirus type 2 (PCV2)-associated disease (PCVAD) continues to be an important differential diagnosis on pig farms in the United States and worldwide. Case trend analyses indicate that the incidence of PCVAD is on the rise in the United States. Accurate diagnosis is important in order to implement appropriate intervention strategies. PCVAD can manifest as a systemic disease, as part of the respiratory disease complex, as an enteric disease, as porcine dermatitis and nephropathy syndrome, or as reproductive problems. PCVAD may be only a sporadic individual animal diagnosis; however, PCVAD may also manifest as a severe herd problem accelerated and enhanced by concurrent virus or bacterial infections. This article is intended to discuss the most common disease manifestations, pathogenesis, diagnostic approaches, and intervention strategies associated with PCVAD in North America.
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Affiliation(s)
- Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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26
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McKeown NE, Opriessnig T, Thomas P, Guenette DK, Elvinger F, Fenaux M, Halbur PG, Meng XJ. Effects of porcine circovirus type 2 (PCV2) maternal antibodies on experimental infection of piglets with PCV2. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2006; 12:1347-51. [PMID: 16275955 PMCID: PMC1287757 DOI: 10.1128/cdli.12.11.1347-1351.2005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To determine the effects of porcine circovirus type 2 (PCV2) maternal antibodies on and response to experimental PCV2 infection, 24 piglets were divided into four groups on the basis of the enzyme-linked immunosorbent assay titers of PCV2 maternal antibodies: group A (n = 6; sample/positive [S/P] ratio, <0.2), group B (n = 5; S/P ratio, >0.2 to <0.5), and groups C (n = 8) and D (n = 5) (S/P ratio, >0.5). Piglets in groups A, B, and C were inoculated with PCV2 at day 0 and challenged with PCV2 at day 42. Group D piglets were not exposed to PCV2 at day 0 but were challenged at day 42. Before challenge, seroconversion to PCV2 antibodies occurred in five of six group A piglets, and the antibody level rose above the cutoff level in one of five group B piglets. Viremia was detected in five of six, four of five, and two of eight pigs in groups A, B, and C, respectively. After challenge, PCV2 DNA was detectable from 7 to 21 days postchallenge in the sera from six of six, four of five, three of eight, and five of five pigs in groups A, B, C, and D, respectively. The results indicated that protection against PCV2 infection conferred by maternal antibodies is titer dependent: higher titers are generally protective, but low titers are not.
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Affiliation(s)
- N E McKeown
- Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 1410 Price's Fork Road, Blacksburg, Virginia 24061-0342, USA
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Quintana J, Segalés J, Calsamiglia M, Domingo M. Detection of porcine circovirus type 1 in commercial pig vaccines using polymerase chain reaction. Vet J 2005; 171:570-3. [PMID: 16624728 DOI: 10.1016/j.tvjl.2004.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2004] [Indexed: 10/25/2022]
Abstract
The absence of extraneous viruses is a requirement in the quality control of vaccines for veterinary use in the European Pharmacopoeia. A polymerase chain reaction (PCR) assay for the detection of porcine circovirus type 1 (PCV1) and type 2 (PCV2) was evaluated in 18 commercial porcine vaccines. Since vaccine components may contain PCR enhancers or inhibitors, 13 of the studied vaccines (used as diluents) were subsequently spiked with different dilutions of PCV2 and tested by PCR. Although PCV2 DNA was not detected in any of the vaccines tested, PCV1 was detected in 2/18 vaccines (11%). Eleven out of 13 PCV2 spiked vaccines showed a positive PCR result. The lack of amplification observed in two spiked vaccines suggested that use of the PCR assay to detect PCV2 could depend on vaccine composition. The results of this exploratory study have demonstrated that PCR is a rapid and fairly sensitive method for the detection of porcine circoviruses as extraneous agents in vaccine products and can be used in the quality control of pig vaccines. The study has also indicated the need for optimising the sensitivity of PCR methods for PCV genome detection in vaccine products.
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Affiliation(s)
- Josefina Quintana
- Centre de Recerca en Sanitat Animal (CReSA), Departament de Sanitat i d'Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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