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Sahoo M, Pathak M, Patel SK, Saikumar G, Upmanyu V, Thakor JC, Kumar P, Singh R, Singh K, Sahoo NR. Pathomorphology, immunohistochemical, and molecular detection of an atypical porcine dermatitis and nephropathy syndrome (PDNS) due to PCV-2d-2 in naturally affected grower pigs of India. Microb Pathog 2022; 171:105738. [PMID: 36038085 DOI: 10.1016/j.micpath.2022.105738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/16/2022] [Accepted: 08/20/2022] [Indexed: 11/19/2022]
Abstract
Porcine circovirus type 2 (PCV-2) is of great economic significance to porcine industry worldwide. PCV-2 variants and genotypes, alternating world over, are the etiological agent of several clinical syndromes such as porcine dermatitis and nephropathy syndrome (PDNS), post-weaning multi-systemic wasting syndrome (PMWS) and others in pigs. This study is reporting an atypical manifestation of PDNS in twelve grower pigs, 3- to - 4.5 months age and either sex, died of the disease, with predominant lesions of nephropathy and no obvious clinical lesions in skin. Necropsy examination of pigs showed lesions of petechial -to- ecchymotic hemorrhages in the kidneys and in the right auricular musculature of the hearts. Microscopic lesions in H & E sections of the kidneys showed acute glomerulonephritis, interstitial nephritis, and vasculitis, but the skin morphology and architecture remained unaltered in contrast to the pathognomonic lesions of PDNS described in the literature. Other syndromic associations of PDNS in these cases included-perimyocarditis, interstitial pneumonia, depleted lymphoid tissues, tonsillitis, enteritis, and meningo-encephalitis. The lesional sites in duplicate paraffin tissue sections of kidneys, heart, lungs, spleen, lymph nodes, intestine, and brain demonstrated PCV-2 antigen in the cytoplasm of cells as highlighted by the intense immunolabeling on IHC staining. The PCV-2 positive organs reconfirmed by PCR, targeting ORF2 gene, which yielded 481bp size of products. The sequencing results of 481bp products on phylogenetic analysis showed 94% similarity with that of PCV-2 sequences in the database that grouped into PCV2d-2 genotype. The present report confirms, probably for the first time, the atypical PDNS cases due to PCV2d-2 genotype in naturally affected grower pigs of India.
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Affiliation(s)
- Monalisa Sahoo
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India.
| | - Mamta Pathak
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India
| | - Shailesh Kumar Patel
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India; Department of Veterinary Pathology, College of Veterinary Science & Animal Husbandry, Rewa, Madhya Pradesh, India
| | - G Saikumar
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India.
| | - Vikramaditya Upmanyu
- Division of Biological Standardization, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India
| | | | - Pradeep Kumar
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India
| | - Rajendra Singh
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, India; Veterinary Pathology, Institute of Veterinary Science and Animal Husbandry, Siksha "O" Anusandhan, Ghatikia, Bhubaneswar, Odisha, India
| | - Karampal Singh
- ICAR-CADRAD, Indian Veterinary Research Institute (IVRI), Izatnagar, India
| | - Nihar Ranjan Sahoo
- ICAR-DFMD-International Centre for Foot and Mouth Disease, Arugul, Jatni, Bhubaneswar, Odisha, India
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Sirisereewan C, Thanawongnuwech R, Kedkovid R. Current Understanding of the Pathogenesis of Porcine Circovirus 3. Pathogens 2022; 11:pathogens11010064. [PMID: 35056012 PMCID: PMC8778431 DOI: 10.3390/pathogens11010064] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 02/07/2023] Open
Abstract
Circoviruses are closed, circular, single-stranded DNA viruses belonging to the family Circoviridae and the genus Circovirus. To date, at least four porcine circoviruses (PCVs) have been recognized, including PCV1 to PCV4, respectively. Similar to PCV2 pathogenesis, PCV3 has been reported worldwide with myriad clinical and pathological presentations such as reproductive disorders, respiratory diseases, diarrhea etc. Current understanding of PCV3 pathogenesis is very limited since the majority of studies were mostly field observations. Interpretation of the results from such studies is not always simple. Various confounding factors affect the clinical appearance and pathological changes of the infected pigs. Recently, several experimental PCV3 infection studies have been reported, providing a better understanding of its pathogenesis. In this review, we focused on novel findings regarding PCV3 pathogenesis from both field observation and experimental infection studies. Possible factors involved in the conflicting results among the experimental infection studies are also discussed. This review article provides important insight into the current knowledge on PCV3 pathogenesis which would aid in prioritizing research in order to fill the knowledge gaps.
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Affiliation(s)
- Chaitawat Sirisereewan
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand;
| | - Roongroje Thanawongnuwech
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand;
- Correspondence: (R.T.); (R.K.)
| | - Roongtham Kedkovid
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
- Swine Reproduction Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence: (R.T.); (R.K.)
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Blanch-Lázaro B, Ribot RF, Berg ML, Alexandersen S, Bennett AT. Ability to detect antibodies to beak and feather disease virus in blood on filter paper decreases with duration of storage. PeerJ 2021; 9:e12642. [PMID: 35036139 PMCID: PMC8697771 DOI: 10.7717/peerj.12642] [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: 07/08/2021] [Accepted: 11/24/2021] [Indexed: 11/25/2022] Open
Abstract
Background Beak and feather disease virus (BFDV) is a circovirus that infects captive and wild psittacine birds, and is of conservation concern. The haemagglutination inhibition (HI) assay is used to determine antibody titres against BFDV, and the use of dried blood spots (DBS) on filter paper stored at room temperature has been suggested to be an equally valid technique to the use of frozen serum. However, research on other pathogens has found variable results when investigating the longevity of antibodies stored on DBS at room temperature. Consequently, we aimed to test the temporal stability of antibodies to BFDV in DBS samples stored long-term at room temperature. A further goal was to add to the current knowledge of antibody response to naturally acquired BFDV infection in crimson rosellas (Platycercus elegans). Methods Blood was collected from wild P. elegans in Victoria, Australia, that had been live-trapped (n = 9) or necropsied (n = 11). BFDV virus load data were obtained from blood stored in ethanol by real-time quantitative PCR (qPCR); antibody titres were obtained by HI assay from either DBS or serum samples, which had been collected concurrently. All HI assays were performed commercially by the Veterinary Diagnostic Laboratory (VDL) in Charles Sturt University, Australia, who were blind to BFDV blood status. Results HI titres from DBS stored at room temperature declined significantly over time (~80 weeks). By contrast, frozen serum samples assayed after 80 weeks in storage all had high HI titres, only varying up to one dilution step from the initial HI titres obtained from DBS at 3–6 weeks after sampling. Weak HI titres from DBS samples all came back negative when the test was repeated only nine weeks later. Novel high HI titres were reported in P. elegans, and while most birds with high antibody titres had corresponding negative qPCR results, a single subadult presented with high HI titres and virus load simultaneously. Conclusion Detection of antibodies on filter paper stored at room temperature decreases over time, increasing the chances of false negatives in these samples, and in repeated testing of samples with weak HI titres. Consequently, serum should be the preferred sample type to use for seroepidemiological studies on BFDV in parrots and other bird species. When not possible, it may help to store DBS on filter paper at −20 °C or lower. However, prompt testing of DBS samples (e.g., <6 weeks in storage) is recommended pending further research on antibody temporal stability. We also show that P. elegans, especially adults, can produce high antibody titres against BFDV, which may help them resist infection.
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Affiliation(s)
- Berta Blanch-Lázaro
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
- Geelong Centre for Emerging Infectious Diseases, Geelong, Victoria, Australia
| | - Raoul F.H. Ribot
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Mathew L. Berg
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Soren Alexandersen
- Geelong Centre for Emerging Infectious Diseases, Geelong, Victoria, Australia
- School of Medicine, Deakin University, Geelong, Victoria, Australia
- Barwon Health, Geelong, Victoria, Australia
| | - Andrew T.D. Bennett
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
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Chen W, Fan J, Li Z, Zhang Y, Qin Y, Wu K, Li X, Li Y, Fan S, Zhao M. Development of Recombinase Aided Amplification Combined With Disposable Nucleic Acid Test Strip for Rapid Detection of Porcine Circovirus Type 2. Front Vet Sci 2021; 8:676294. [PMID: 34250063 PMCID: PMC8267240 DOI: 10.3389/fvets.2021.676294] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) is the dominant causative agent of PCV2 systemic disease (PCV2-SD) in pigs. It can also associate with other diseases such as respiratory and enteric diseases, reproductive failure, porcine dermatitis and nephropathy syndrome in pigs. Currently, PCV2 infection is a considerable threat in the swine industry. Therefore, it is of great significance to prevent, control, and accurately detect PCV2 in pig farms. Recombinase aided amplification (RAA) technology is an isothermal nucleic acid amplification technology that could rapidly amplify the target gene fragment at a constant temperature. The amplification products labeled with specific molecules could be visually detected using the test strip with the corresponding antibody. In the present study, the RAA technology combined with a nucleic acid test strip (RAA-strip) was established for simple and specific detection of PCV2. Primers and probes targeting the PCV2 ORF2 gene were designed according to the RAA technology principles. The PCV2 RAA-strip established in this study could detect as low as 103 copies/μL of recombinant plasmids containing the PCV2 ORF2 gene fragment. The lowest detection limit about viral DNA and virus titers was 6.7 × 10-6 ng/μL and 10 TCID50/mL, respectively. Furthermore, no cross-reaction with other porcine viruses occurred at 37°C and within 15 min. We used 42 clinical samples to assess the performance of our established method. The positive rate of clinical samples detected by PCV2 RAA-strip was 50.00%. This was similar to that detected by PCV2 PCR (45.24%). In conclusion, due to the advantages of strong specificity, high sensitivity, excellent reproducibility, and simple operation method, our PCV2 RAA-strip is suitable for the rapid clinical detection of PCV2 on-site.
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Affiliation(s)
- Wenxian Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Jindai Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Zhaoyao Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yuanyuan Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Yuwei Qin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Keke Wu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Xiaowen Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Yuwan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Shuangqi Fan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
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Dhondt L, Croubels S, Temmerman R, De Cock P, Meyer E, Van Den Broeck W, De Paepe P, Devreese M. The Development of a Juvenile Porcine Augmented Renal Clearance Model Through Continuous Infusion of Lipopolysaccharides: An Exploratory Study. Front Vet Sci 2021; 8:639771. [PMID: 33996970 PMCID: PMC8116505 DOI: 10.3389/fvets.2021.639771] [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: 12/09/2020] [Accepted: 03/09/2021] [Indexed: 12/29/2022] Open
Abstract
Augmented renal clearance (ARC) as observed in the critically ill (pediatric) population can have a major impact on the pharmacokinetics and posology of renally excreted drugs. Although sepsis has been described as a major trigger in the development of ARC in human critically ill patients, mechanistic insights on ARC are currently lacking. An appropriate ARC animal model could contribute to reveal these underlying mechanisms. In this exploratory study, a state of ARC was induced in 8-week-old piglets. Conscious piglets were continuously infused over 36 h with lipopolysaccharides (LPS) from Escherichia coli (O111:B4) to induce sepsis and subsequently trigger ARC. To study the dose-dependent effect of LPS on the renal function, three different doses (0.75, 2.0, 5.0 μg/kg/h) were administered (two ♂ piglets/dose, one sham piglet), in combination with fluid administration (0.9% NaCl) at 6 ml/kg/h. Single boluses of renal markers, i.e., creatinine [40 mg/kg body weight (BW)], iohexol (64.7 mg/kg BW), and para-aminohippuric acid (PAH, 10 mg/kg BW) were administered intravenously to evaluate the effect of LPS on the renal function. Clinical parameters were monitored periodically. Blood sampling was performed to determine the effect on hematology, neutrophil gelatinase-associated lipocalin, and prostaglandin E2 plasma levels. All piglets that were continuously infused with LPS displayed an elevated body temperature, heart rhythm, and respiratory rate ~1-3 h after start of the infusion. After infusion, considerably higher total body clearances of iohexol, creatinine, and PAH were observed, independent of the administration of LPS and/or its dose. Since also the sham piglet, receiving no LPS, demonstrated a comparable increase in renal function, the contribution of fluid administration to the development of ARC should be further evaluated.
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Affiliation(s)
- Laura Dhondt
- Department of Pharmacology, Toxicology and Biochemistry, Ghent University, Ghent, Belgium
| | - Siska Croubels
- Department of Pharmacology, Toxicology and Biochemistry, Ghent University, Ghent, Belgium
| | - Robin Temmerman
- Department of Pharmacology, Toxicology and Biochemistry, Ghent University, Ghent, Belgium
| | - Pieter De Cock
- Department of Pharmacy, Ghent University Hospital, Ghent, Belgium.,Heymans Institute of Pharmacology, Ghent University, Ghent, Belgium.,Department of Paediatric Intensive Care, Ghent University Hospital, Ghent, Belgium
| | - Evelyne Meyer
- Department of Pharmacology, Toxicology and Biochemistry, Ghent University, Ghent, Belgium
| | - Wim Van Den Broeck
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Peter De Paepe
- Heymans Institute of Pharmacology, Ghent University, Ghent, Belgium
| | - Mathias Devreese
- Department of Pharmacology, Toxicology and Biochemistry, Ghent University, Ghent, Belgium
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Piva MM, Schwertz CI, Bianchi RM, Kemper RT, Henker LC, Nagae RY, Cê TRM, Barcellos DES, Driemeier D, Pavarini SP. Causes of death in growing-finishing pigs in two technified farms in southern Brazil. PESQUISA VETERINÁRIA BRASILEIRA 2020. [DOI: 10.1590/1678-5150-pvb-6708] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT: The aim of this study was to investigate the main causes of death in growing-finishing pigs in southern Brazil. During a one-year period (from 2018 to 2019), two industrial pig herds (18 and 20 thousand pigs each farm) in southern Brazil were monitored along the four seasons of the year (12 days per season on each farm), in order to perform necropsies of all pigs that died in that period. The two farms had an average monthly mortality rate ranging from 0.94 to 3.93% in the evaluated months. At necropsy, tissues were collected, fixed in 10% formalin solution and processed routinely for histopathological examination. When necessary, samples were sent for bacterial culture and PCR to identify etiologic agents. A total of 601 necropsies were performed, with 94.9% of conclusive diagnoses. Infectious diseases corresponded to 64.4% of conclusive diagnosis and non-infectious diseases to 35.6%. The most prevalent causes of death were: pneumonia (33%), gastric ulcers (15.4%), circovirosis (9.9%), systemic bacterial embolism (5.4%), polyserositis (4.4%), dilated cardiomyopathy and torsion of abdominal organs (4.3% each), and bacterial pericarditis (3.4%). Regarding pneumonias (199/601), the main agents identified in these cases were Pasteurella multocida, Influenza A virus and Mycoplasma hyopneumoniae, mainly in associations.
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Affiliation(s)
| | | | | | | | | | - Ricardo Y. Nagae
- Empresa Seara Alimentos, Brazil; Universidade Federal do Rio Grande do Sul, Brazil
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Pereira PR, Bianchi RM, Hammerschmitt ME, Cruz RA, Hesse KL, Sonne L, Pavarini SP, Driemeier D. Primary skin diseases and cutaneous manifestations of systemic diseases in swine. PESQUISA VETERINÁRIA BRASILEIRA 2020. [DOI: 10.1590/1678-5150-pvb-6704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
ABSTRACT: Skin diseases in pigs can negatively impact the production. They cause losses related to the death of the affected pigs, to the cost with the treatment, growth retardation and condemnations in the slaughterhouses. This study was developed to determine the frequency and describe the histopathological findings of skin diseases in pigs in different age groups through a retrospective study from 2006 to 2018. A total of 154 conclusive cases were analyzed, including skin restricted diseases (allergic dermatitis, exudative epidermitis, vesicular dermatitis, pityriasis rosea, swinepox, follicular cyst, papilloma and scrotal hemangioma) or skin lesions secondary to systemic diseases (erysipelas, porcine dermatitis and nephropathy syndrome (PDNS), bacterial septicemia and multiple hemorrhages without definite cause). The skin lesions were classified as bacterial (46.1%), viral (26.6%), allergic (12.3%), neoplastic (1.3%) and others (13.6%). Swine erysipelas was the most frequent diagnosis (47/154), followed by PDNS (23/154), allergic dermatitis (19/154) and exudative epidermitis (15/154). Vesicular dermatitis (9/154), pityriasis rosea (9/154), septicemia with cutaneous manifestations (9/154), swinepox (9/154) and multiple hemorrhages without definite cause (7/154) were also observed. Follicular cyst (3/154), hyperkeratosis without definite cause (2/154), papilloma (1/154), and scrotal hemangioma (1/154) were less frequently described. Of the conclusive diagnosis, age was reported in 138 cases, with the highest frequency of skin lesions observed at the inspection process during slaughter (56/138).
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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: 27] [Impact Index Per Article: 3.9] [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.
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A Novel Porcine Circovirus Distantly Related to Known Circoviruses Is Associated with Porcine Dermatitis and Nephropathy Syndrome and Reproductive Failure. J Virol 2016; 91:JVI.01879-16. [PMID: 27795441 DOI: 10.1128/jvi.01879-16] [Citation(s) in RCA: 386] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 10/20/2016] [Indexed: 01/21/2023] Open
Abstract
Porcine circovirus-associated disease (PCVAD) is clinically manifested by postweaning multisystemic wasting syndrome (PMWS), respiratory and enteric disease, reproductive failure, and porcine dermatitis and nephropathy syndrome (PDNS). Porcine circovirus 2 (PCV2) is an essential component of PCVAD, although an etiologic role in PDNS is not well established. Here, a novel circovirus, designated porcine circovirus 3 (PCV3), was identified in sows that died acutely with PDNS-like clinical signs. The capsid and replicase proteins of PCV3 are only 37% and 55% identical to PCV2 and bat circoviruses, respectively. Aborted fetuses from sows with PDNS contained high levels of PCV3 (7.57 × 107 genome copies/ml), and no other viruses were detected by PCR and metagenomic sequencing. Immunohistochemistry (IHC) analysis of sow tissue samples identified PCV3 antigen in skin, kidney, lung, and lymph node samples localized in typical PDNS lesions, including necrotizing vasculitis, glomerulonephritis, granulomatous lymphadenitis, and bronchointerstitial pneumonia. Further study of archived PDNS tissue samples that were negative for PCV2 by IHC analysis identified 45 of 48 that were PCV3 positive by quantitative PCR (qPCR), with 60% of a subset also testing positive for PCV3 by IHC analysis. Analysis by qPCR of 271 porcine respiratory disease diagnostic submission samples identified 34 PCV3-positive cases (12.5%), and enzyme-linked immunosorbent assay detection of anti-PCV3 capsid antibodies in serum samples found that 46 (55%) of 83 samples tested were positive. These results suggest that PCV3 commonly circulates within U.S. swine and may play an etiologic role in reproductive failure and PDNS. Because of the high economic impact of PCV2, this novel circovirus warrants further studies to elucidate its significance and role in PCVAD. IMPORTANCE While porcine circovirus 2 (PCV2) was first identified in sporadic cases of postweaning multisystemic wasting syndrome in Canada in the early 1990s, an epidemic of severe systemic disease due to PCV2 spread worldwide in the ensuing decade. Despite being effectively controlled by commercial vaccines, PCV2 remains one of the most economically significant viruses of swine. Here, a novel porcine circovirus (PCV3) that is distantly related to known circoviruses was identified in sows with porcine dermatitis and nephropathy syndrome (PDNS) and reproductive failure. PCV2, which has previously been associated with these clinical presentations, was not identified. High levels of PCV3 nucleic acid were observed in aborted fetuses by quantitative PCR, and PCV3 antigen was localized in histologic lesions typical of PDNS in sows by immunohistochemistry (IHC) analysis. PCV3 was also identified in archival PDNS diagnostic samples that previously tested negative for PCV2 by IHC analysis. The emergence of PCV3 warrants further investigation.
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Opriessnig T, Xiao CT, Halbur PG, Gerber PF, Matzinger SR, Meng XJ. A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions. Vaccine 2016; 35:248-254. [PMID: 27919634 PMCID: PMC5221148 DOI: 10.1016/j.vaccine.2016.11.085] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/17/2016] [Accepted: 11/24/2016] [Indexed: 11/04/2022]
Abstract
Porcine circovirus type 2 (PCV2) vaccination has been effective in protecting pigs from clinical disease and today is used extensively. Recent studies in vaccinated populations indicate a major PCV2 genotype shift from the predominant PCV2 genotype 2b towards 2d. The aims of this study were to determine the ability of the commercial inactivated PCV2a vaccine Circovac® to protect pigs against experimental challenge with a 2013 PCV2d strain and prevent transmission. Thirty-eight pigs were randomly divided into four groups with 9–10 pigs per group: NEG (sham-vaccinated, sham-challenged), VAC (PCV2a-vaccinated, sham-challenged), VAC + CHAL (PCV2a-vaccinated and PCV2d-challenged), and CHAL (sham-vaccinated, PCV2d-challenged). Vaccination was done at 3 weeks of age using Circovac® according to label instructions. The CHAL and VAC + CHAL groups were challenged with PCV2d at 7 weeks of age and all pigs were necropsied 21 days post-challenge (dpc). The VAC-CHAL pigs seroconverted to PCV2 by 21 days post vaccination (dpv). At PCV2d challenge on 28 dpv, 3/9 VAC and 1/9 VAC + CHAL pigs were seropositive. NEG pigs remained seronegative for the duration of the study. Vaccination significantly reduced PCV2d viremia (VAC + CHAL) at dpc 14 and 21, PCV2d fecal shedding at dpc 14 and 21 and PCV2d nasal shedding at dpc 7, 14 and 21 compared to CHAL pigs. Vaccination significantly reduced mean PCV2 antigen load in lymph nodes in VAC + CHAL pigs compared to CHAL pigs. When pooled serum or feces collected from VAC + CHAL and CHAL pigs at dpc 21 were used to expose single-housed PCV2 naïve pigs, a pooled fecal sample from CHAL pigs contained infectious PCV2 whereas this was not the case for VAC + CHAL pigs suggesting reduction of PCV2d transmission by vaccination. Under the study conditions, the PCV2a-based vaccine was effective in reducing PCV2d viremia, tissue loads, shedding and transmission indicating that PCV2a vaccination should be effective in PCV2d-infected herds.
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Affiliation(s)
- Tanja Opriessnig
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK; Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
| | - Chao-Ting Xiao
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; College of Biology, Hunan University, Changsha, China
| | - Patrick G Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Priscilla F Gerber
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK
| | - Shannon R Matzinger
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Li Y, Liu H, Wang P, Wang L, Sun Y, Liu G, Zhang P, Kang L, Jiang S, Jiang Y. RNA-Seq Analysis Reveals Genes Underlying Different Disease Responses to Porcine Circovirus Type 2 in Pigs. PLoS One 2016; 11:e0155502. [PMID: 27171165 PMCID: PMC4865221 DOI: 10.1371/journal.pone.0155502] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/30/2016] [Indexed: 11/18/2022] Open
Abstract
Porcine circovirus type 2 (PCV2), an economically important pathogen, causes postweaning multisystemic wasting syndrome (PMWS) and other syndrome diseases collectively known as porcine circovirus-associated disease (PCVAD). Previous studies revealed breed-dependent differences in porcine susceptibility to PCV2; however, the genetic mechanism underlying different resistance to PCV2 infection remains largely unknown. In this study, we found that Yorkshire × Landrace (YL) pigs exhibited serious clinical features typifying PCV2 disease, while the Laiwu (a Chinese indigenous pig breed, LW) pigs showed little clinical symptoms of the disease during PCV2 infection. At 35 days post infection (dpi), the PCV2 DNA copy in YL pigs was significantly higher than that in LW pigs (P < 0.05). The serum level of IL-4, IL-6, IL-8, IL-12 and TGF-β1 in LW pigs and TNF-α in YL pigs increased significantly at the early infected stages, respectively; while that of IL-10 and IFN-γ in YL pigs was greatly increased at 35 dpi. RNA-seq analysis revealed that, at 35 dpi, 83 genes were up-regulated and 86 genes were down-regulated in the lung tissues of LW pigs, while in YL pigs, the numbers were 187 and 18, respectively. In LW pigs, the differentially expressed genes (DEGs) were mainly involved in complement and coagulation cascades, metabolism of xenobiotics by cytochrome P450, RIG-I-like receptor signaling and B cell receptor signaling pathways. Four up-regulated genes (TFPI, SERPNC1, SERPNA1, and SERPNA5) that are enriched in complement and coagulation cascades pathway were identified in the PCV2-infected LW pigs, among which the mRNA expression of SERPNA1, as well as three genes including TGF-β1, TGF-β2 and VEGF that are regulated by SERPNA1 was significantly increased (P < 0.05). We speculate that higher expression of SERPNA1 may effectively suppress excessive inflammation reaction and reduce the pathological degree of lung tissue in PCV2-infected pigs. Collectively, our findings indicate that the susceptibility to PCV2 infection depends on a genetic difference between LW and YL pigs, and SERPNA1 likely plays an important role in the resistance of LW pigs to PCV2 infection.
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Affiliation(s)
- Yanping Li
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Hao Liu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Pengfei Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Liyuan Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Yi Sun
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Gen Liu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Ping Zhang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Li Kang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Shijin Jiang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Yunliang Jiang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
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12
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Abstract
Swine are used in biomedical research as models for biomedical research and for teaching. This chapter covers normative biology and behavior along with common and emerging swine diseases. Xenotransplantation is discussed along with similarities and differences of swine immunology.
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Affiliation(s)
- Kristi L. Helke
- Departments of Comparative Medicine and Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | | | - Raimon Duran-Struuck
- Columbia Center of Translational Immunology, Department of Surgery; Institute of Comparative Medicine; Columbia University Medical Center, New York, NY, USA
| | - M. Michael Swindle
- Medical University of South Carolina, Department of Comparative Medicine and Department of Surgery, Charleston, SC, USA
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Single-tube multiplexed molecular detection of endemic porcine viruses in combination with background screening for transboundary diseases. J Clin Microbiol 2013; 51:938-44. [PMID: 23303496 DOI: 10.1128/jcm.02947-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Detection of several pathogens with multiplexed real-time quantitative PCR (qPCR) assays in a one-step setup allows the simultaneous detection of two endemic porcine and four different selected transboundary viruses. Reverse transcription (RT)-qPCR systems for the detection of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2), two of the most economically important pathogens of swine worldwide, were combined with a screening system for diseases notifiable to the World Organization of Animal Health, namely, classical and African swine fever, foot-and-mouth disease, and Aujeszky's disease. Background screening was implemented using the identical fluorophore for all four different RT-qPCR assays. The novel multiplex RT-qPCR system was validated with a large panel of different body fluids and tissues from pigs and other animal species. Both reference samples and clinical specimens were used for a complete evaluation. It could be demonstrated that a highly sensitive and specific parallel detection of the different viruses was possible. The assays for the notifiable diseases were even not affected by the simultaneous amplification of very high loads of PRRSV- and PCV2-specific sequences. The novel broad-spectrum multiplex assay allows in a unique form the routine investigation for endemic porcine pathogens with exclusion diagnostics of the most important transboundary diseases in samples from pigs with unspecific clinical signs, such as fever or hemorrhages. The new system could significantly improve early detection of the most important notifiable diseases of swine and could lead to a new approach in syndromic surveillance.
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14
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Abstract
Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated disease (PCVAD). The virus preferentially targets the lymphoid tissues, which leads to lymphoid depletion and immunosuppression in pigs. The disease is exacerbated by immunostimulation or concurrent infections with other pathogens. PCV2 resides in certain immune cells, such as macrophage and dendritic cells, and modulates their functions. Upregulation of IL-10 and proinflammatory cytokines in infected pigs may contribute to pathogenesis. Pig genetics influence host susceptibility to PCV2, but the viral genetic determinants for virulence remain unknown. PCV2 DNA and proteins interact with various cellular genes that control immune responses to regulate virus replication and pathogenesis. Both neutralizing antibodies and cell-mediated immunity are important immunological correlates of protection. Despite the availability of effective vaccines, variant strains of PCV2 continue to emerge. Although tremendous progress has been made toward understanding PCV2 pathogenesis and immune interactions, many important questions remain.
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Affiliation(s)
- Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061;
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15
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High-level expression and immunogenicity of a porcine circovirus type 2 capsid protein through codon optimization in Pichia pastoris. Appl Microbiol Biotechnol 2012; 97:2867-75. [DOI: 10.1007/s00253-012-4540-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 10/20/2012] [Accepted: 10/22/2012] [Indexed: 02/07/2023]
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16
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Hemann M, Shen HG, Beach NM, Meng XJ, Halbur PG, Opriessnig T. Expression of human CD46 has no effect on porcine circovirus type 2 infection and shedding in the experimental pig model. Vet Res Commun 2012; 36:187-93. [PMID: 22388862 DOI: 10.1007/s11259-012-9524-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2012] [Indexed: 01/05/2023]
Abstract
Xenotransplantation of tissues from transgenic pigs with desired genetic modifications such as CD46 expression help minimize xenograft rejections. However, CD46 is a known receptor for some viruses. In this study, pigs transgenic for human CD46 (CD46-TG) and appropriate non-transgenic (non-TG) control pigs were utilized to determine possible differences in the level of replication and shedding of porcine circovirus type 2 (PCV2). Non-TG and CD46-TG were blocked by transgenic status and randomly divided into three groups: Non-TG negative controls (n = 3), non-TG-PCV2 (n = 10; PCV2a = 5, PCV2b = 5), and CD46-TG-PCV2 (n = 6; PCV2a = 3, PCV2b = 3). Blood, oral, nasal and fecal swabs were collected at regular intervals from the day of arrival until 70 days post inoculation (DPI). All samples were tested by quantitative real-time PCR for the presence of PCV2 DNA and serum was tested for presence of PCV2 antibodies by ELISA. Overall, the main effects "transgenic status" and "PCV2 subtype" had no influence on degree of PCV2 viremia and shedding or the anti-PCV2 humoral immune response in CD46-TG-PCV2 pigs compared to non-TG-PCV2 pigs. Differences in PCV2 concentrations between non-TG-PCV2 and CD46-TG-PCV2 pigs were minimal and limited to DPI 35 in sera, DPI 7 in fecal swabs and DPI 5 in nasal swabs when CD46-TG-PCV2 pigs had significantly higher concentrations of PCV2 DNA. At DPI 1, CD46-TG-PCV2 pigs had significantly lower concentrations of PCV2 DNA in oral swabs. Under the study conditions, the presence of human CD46 in transgenic pigs had no effect on PCV2 infection in otherwise healthy pigs capable of a normal immune response.
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Affiliation(s)
- Michelle Hemann
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA, 50011, USA
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17
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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]
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18
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Genetic variation of porcine circovirus type 2 (PCV2) and its relevance to vaccination, pathogenesis and diagnosis. Virus Res 2012; 164:68-77. [DOI: 10.1016/j.virusres.2011.11.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/10/2011] [Accepted: 11/21/2011] [Indexed: 12/16/2022]
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19
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Segalés J. Porcine circovirus type 2 (PCV2) infections: Clinical signs, pathology and laboratory diagnosis. Virus Res 2012; 164:10-9. [DOI: 10.1016/j.virusres.2011.10.007] [Citation(s) in RCA: 384] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 10/10/2011] [Accepted: 10/11/2011] [Indexed: 12/18/2022]
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20
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Torque teno sus virus 1 and 2 viral loads in postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS) affected pigs. Vet Microbiol 2011; 153:377-81. [PMID: 21719215 DOI: 10.1016/j.vetmic.2011.05.046] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 05/26/2011] [Accepted: 05/31/2011] [Indexed: 11/22/2022]
Abstract
Torque teno viruses (TTV) are small, non-enveloped viruses with a circular single-stranded DNA genome, which are considered non-pathogenic. However, TTVs have been eventually linked to human diseases. TTVs infecting pigs, Torque teno sus virus 1 (TTSuV1) and 2 (TTSuV2), have been recently associated to porcine circovirus diseases (PCVD). To get more insights into such potential disease association, the aim of this study was to quantify TTSuV1 and TTSuV2 viral loads in serum of pigs affected by two PCVDs, postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). Such study was carried out by means of a newly developed real-time quantitative PCR (qPCR) method. Both TTSuVs were highly prevalent among studied pigs. TTSuV2 viral loads were significantly higher in PMWS affected animals, further supporting the previously suggested association between TTSuV2 and PMWS. On the contrary, TTSuV1 prevalence and loads were not related with the studied PCVDs.
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21
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Antibody recognition of porcine circovirus type 2 capsid protein epitopes after vaccination, infection, and disease. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:749-57. [PMID: 21430122 DOI: 10.1128/cvi.00418-10] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Open reading frame 2 (ORF2) of porcine circovirus type 2 (PCV2) codes for the 233-amino-acid capsid protein (CP). Baculovirus-based vaccines that express only ORF2 are protective against clinical disease following experimental challenge or natural infection. The goal of this study was to identify regions in CP preferentially recognized by sera from experimentally infected and vaccinated pigs and to compare these responses to those of pigs diagnosed with porcine circovirus-associated disease (PCVAD), including porcine multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). The approach was to react porcine sera with CP polypeptide fragments followed by finer mapping studies using overlapping oligopeptides that covered amino acids 141 to 200. The results showed that vaccinated pigs preferentially recognized only the largest polypeptide fragment, CP(43-233). A subset of experimentally infected pigs and pigs with PDNS showed strong reactivity against a CP oligopeptide, 169-STIDYFQPNNKR-180. Alanine scanning identified Y-173, F-174, Q-175, and K-179 as important for antibody recognition. The results from this study support the notion of PCV2 modulation of immunity, including antibody responses that may represent a precursor for disease. The recognition of CP(169-180) and other polypeptides provides opportunities to devise diagnostic tests for monitoring the immunological effectiveness of vaccination.
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22
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Characterization of a new disease syndrome associated with porcine circovirus type 2 in previously vaccinated herds. J Clin Microbiol 2011; 49:2012-6. [PMID: 21346043 DOI: 10.1128/jcm.02543-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Porcine circovirus-associated disease (PCVAD) encompasses a group of wasting syndromes linked to porcine circovirus type 2 (PCV2). This paper describes a new PCV2 disease syndrome, called acute pulmonary edema (APE), which, unlike other PCVAD syndromes, has a peracute onset and is associated with herds vaccinated for PCV2.
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23
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A study on the severity and relevance of porcine circovirus type 2 infections in Dutch fattening pigs with respiratory diseases. Vet Microbiol 2010; 142:217-24. [DOI: 10.1016/j.vetmic.2009.10.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 09/27/2009] [Accepted: 10/02/2009] [Indexed: 11/19/2022]
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24
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Genetic diversity of porcine circovirus type 2 from pigs in Republic of Korea. Res Vet Sci 2010; 88:333-8. [DOI: 10.1016/j.rvsc.2009.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 08/03/2009] [Accepted: 08/07/2009] [Indexed: 11/18/2022]
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25
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Langohr IM, Stevenson GW, Nelson EA, Lenz SD, HogenEsch H, Wei H, Pogranichniy RM. Vascular lesions in pigs experimentally infected with porcine circovirus type 2 serogroup B. Vet Pathol 2010; 47:140-7. [PMID: 20080495 DOI: 10.1177/0300985809352793] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Vasculitis is a hallmark lesion of the severe form of systemic porcine circovirus-associated disease (PCVAD). In 2 experimental studies with porcine circovirus type 2 serogroup b (PCV2b), 2 pigs developed fatal PCVAD with acute vasculitis, and 5 related pigs developed chronic lymphohistiocytic and plasmacytic peri- and endarteritis. Five of these pigs (1 with acute vasculitis and 4 with chronic vasculitis) had also been inoculated with bovine viral diarrhea virus type 1 (BVDV1) or BVDV1-like virus. Vascular lesions were similar, independent of whether pigs had been inoculated singly with PCV2b or dually with PCV2b and BVDV1 or BVDV1-like virus. The acute vasculitis was accompanied by marked pulmonary and mesenteric edema and pleural effusion. In situ hybridization demonstrated abundant intracytoplasmic porcine circovirus type 2 (PCV2) nucleic acid in endothelial, smooth muscle-like, and inflammatory cells within and around affected arteries. The pigs with lymphohistiocytic and plasmacytic vasculitis had lesions of systemic PCVAD, including multisystemic lymphoplasmacytic and histiocytic or granulomatous inflammation. PCV2 nucleic acid was detected in renal tubule epithelial cells, mononuclear inflammatory cells, and rare endothelial cells in noninflamed vessels in multiple tissues of these animals. The 2 pigs with acute vasculitis had no PCV2-specific antibodies (or a low titer of), whereas the pigs with lymphohistiocytic and plasmacytic vasculitis developed high antibody titers against this virus. These observations suggest that (1) acute vasculitis observed in the current studies is directly caused by PCV2b, (2) chronic vasculitis may in part be mediated by the subsequent immune response, and (3) host factors and viral strain may both contribute to vasculitis in animals infected with PCV2b.
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Affiliation(s)
- I M Langohr
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
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26
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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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Andraud M, Rose N, Grasland B, Pierre JS, Jestin A, Madec F. Influence of husbandry and control measures on porcine circovirus type 2 (PCV-2) dynamics within a farrow-to-finish pig farm: a modelling approach. Prev Vet Med 2009; 92:38-51. [PMID: 19720410 DOI: 10.1016/j.prevetmed.2009.07.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 11/26/2022]
Abstract
We assessed, using a modelling approach, the influence of several management practices within a farrow-to-finish farm on the age of PCV-2 infection. The impact of PCV-2 vaccination with different vaccination schemes on infection dynamics, was also tested. A stochastic individual-based model describing the population dynamics in a typical French farrow-to-finish pig farm was built and coupled with an epidemiological model of PCV-2 infection. The parameters of the infectious model were mainly obtained from previous transmission experiments. Results were subjected to a survival analysis of time-to-infection. For each comparison, the reference situation was no vaccination followed by random mixing of piglets after birth and after weaning. The risk of early infection was significantly reduced when mixing of piglets was reduced at different stages (avoiding cross-fostering and grouping piglets by litters in small pens after weaning, hazard ratio (HR)=0.52 [0.46; 0.59]). Sow-targeted vaccination delayed the infectious process until the waning of passive immunity and piglet-targeted vaccination considerably decreased the force of infection leading to a dramatic decrease of the total number of infections (HR=0.44 [0.37; 0.54]). The effect was even more pronounced when strict management measures were applied (HR=0.24 [0.19; 0.31]). Changing from a low (3%) prevalence of PCV-2-infected semen to a higher one (18%) significantly increased the risk of early infections (HR=1.36 [1.2; 1.53]), whereas reducing replacement rate or changing sow housing from individual crates to group housing had a limited impact on PCV-2 dynamics.
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Affiliation(s)
- M Andraud
- AFSSA-Site de Ploufragan, Laboratoire d'Etudes et de Recherches Avicole, Porcine et Piscicole, B.P. 53, F-22440 Ploufragan, France.
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28
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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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Horlen KP, Dritz SS, Nietfeld JC, Henry SC, Hesse RA, Oberst R, Hays M, Anderson J, Rowland RRR. A field evaluation of mortality rate and growth performance in pigs vaccinated against porcine circovirus type 2. J Am Vet Med Assoc 2008; 232:906-12. [DOI: 10.2460/javma.232.6.906] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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31
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Lefebvre DJ, Costers S, Van Doorsselaere J, Misinzo G, Delputte PL, Nauwynck HJ. Antigenic differences among porcine circovirus type 2 strains, as demonstrated by the use of monoclonal antibodies. J Gen Virol 2008; 89:177-187. [PMID: 18089741 DOI: 10.1099/vir.0.83280-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study examined whether antigenic differences among porcine circovirus type 2 (PCV-2) strains could be detected using monoclonal antibodies (mAbs). A subtractive immunization protocol was used for the genotype 2 post-weaning multisystemic wasting syndrome (PMWS)-associated PCV-2 strain Stoon-1,010. Sixteen stable hybridomas that produced mAbs with an immunoperoxidase monolayer assay (IPMA) titre of 1,000 or more to Stoon-1,010 were obtained. Staining of recombinant PCV-2 virus-like particles demonstrated that all mAbs were directed against the PCV-2 capsid protein. Cross-reactivity of mAbs was tested by IPMA and neutralization assay for genotype 1 strains 48,285, 1,206, VC2,002 and 1,147, and genotype 2 strains 1,121 and 1,103. Eleven mAbs (9C3, 16G12, 21C12, 38C1, 43E10, 55B1, 63H3, 70A7, 94H8, 103H7 and 114C8) recognized all strains in the IPMA and demonstrated neutralization of Stoon-1,010, 48,285, 1,206 and 1,103, but not VC2,002, 1,147 and 1,121. mAbs 31D5, 48B5, 59C6 and 108E8 did not react with genotype 1 strains or had a reduced affinity compared with genotype 2 strains in the IPMA and neutralization assay. mAb 13H4 reacted in the IPMA with PMWS-associated strains Stoon-1,010, 48,285, 1,206 and VC2,002, and the porcine dermatitis and nephropathy syndrome-associated strain 1,147, but not with reproductive failure-associated strains 1,121 and 1,103. mAb 13H4 did not neutralize any of the tested strains. It was concluded that, despite the high amino acid identity of the capsid protein (>or=91 %), antigenic differences at the capsid protein level are present among PCV-2 strains with a different genetic and clinical background.
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Affiliation(s)
- D J Lefebvre
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - S Costers
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - J Van Doorsselaere
- Department of Health Care and Biotechnology, KATHO Catholic University College of South-West Flanders, Wilgenstraat 32, 8800 Roeselare, Belgium
| | - G Misinzo
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - P L Delputte
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - H J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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32
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Yang ZZ, Shuai JB, Dai XJ, Fang WH. A survey on porcine circovirus type 2 infection and phylogenetic analysis of its ORF2 gene in Hangzhou, Zhejiang Province, China. J Zhejiang Univ Sci B 2008; 9:148-53. [PMID: 18257137 DOI: 10.1631/jzus.b0710395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Porcine circovirus type 2 (PCV2) is closely related to the postweaning multisystemic wasting syndrome (PMWS). In this study, the pig serum and tissue samples collected from different regions of Hangzhou District in Zhejiang Province of China between 2003 and 2005 were analyzed by enzyme-linked immunosorbent assay (ELISA) for PCV2 antibody and by polymerase chain reaction (PCR) for ORF2 gene. The results show that out of 1250 randomly collected serum samples, 500 sera (40%) were seropositive for PCV2. PCR results demonstrate that Hangzhou PCV2 with more than 50% Chinese PCV2 strains and French PCV2 formed Cluster A. Only one PCV2 from Hangzhou belonged to Cluster B with some other Chinese PCV2 and Netherlands's isolates. Cluster C consisted of PCV2 isolates from China, US, Canada, UK and Germany. The results indicate that the PCV2 infection was widespread in Hangzhou.
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Affiliation(s)
- Zong-zhao Yang
- Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029, China
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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: 453] [Impact Index Per Article: 28.3] [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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Influence of maternal antibodies on efficacy of porcine circovirus type 2 (PCV2) vaccination to protect pigs from experimental infection with PCV2. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 15:397-401. [PMID: 18094109 DOI: 10.1128/cvi.00416-07] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Due to the ubiquitous nature of porcine circovirus type 2 (PCV2) in the pig population and the increasing use of PCV2 vaccines in breeding herds, the majority of dams have been exposed to field PCV2 or PCV2 vaccines, resulting in piglets with varied levels of passively acquired PCV2 maternal antibodies. The objective of the current research was to investigate the influence of passively acquired anti-PCV2 antibodies on PCV2 vaccine efficacy. Sixty 26-day-old pigs were divided into four groups: vaccinated pigs with no maternal PCV2 antibodies at the time of vaccination (VAC-NEG; n = 9), vaccinated pigs with maternal PCV2 antibodies at the time of vaccination (VAC-POS; n = 21), nonvaccinated pigs with no maternal antibodies at the time of challenge (NVAC-CNEG; n = 15), and nonvaccinated pigs with maternal antibodies at the time of challenge (NVAC-CPOS; n = 15). Vaccinations and challenges were performed on trial days 0 and 28, respectively, according to group designation. The pigs were monitored for clinical signs of disease daily and weighed weekly, and blood was collected weekly. All pigs were necropsied on trial day 49, and tissues were evaluated for macroscopic and microscopic lesions. Serum was evaluated using PCV2 immunoglobulin G (IgG) and PCV2 IgM enzyme-linked immunosorbent assays, quantitative PCV2 PCR, and a serum PCV2 neutralizing antibody test. In comparison to NVAC-CPOS pigs, VAC-POS animals had significantly (P < 0.01) less severe microscopic PCV2-associated lymphoid lesions and significantly (P < 0.04) reduced PCV2 genomic copies in serum following PCV2 challenge. These results indicate that vaccination with Suvaxyn PCV2 One Dose reduces viremia and prevents microscopic lesions associated with PCV2 in the presence of maternal antibodies.
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Seeliger FA, Brügmann ML, Krüger L, Greiser-Wilke I, Verspohl J, Segalés J, Baumgärtner W. Porcine circovirus type 2-associated cerebellar vasculitis in postweaning multisystemic wasting syndrome (PMWS)-affected pigs. Vet Pathol 2007; 44:621-34. [PMID: 17846234 DOI: 10.1354/vp.44-5-621] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Porcine circovirus type 2 (PCV2) is associated with several syndromes in growing pigs, including postweaning multisystemic wasting syndrome and porcine dermatitis and nephropathy syndrome. In the present study, a previously undescribed neurovascular disorder associated with a PCV2 infection is described. Sixteen pigs showed clinical signs of wasting and neurologic deficits. Acute hemorrhages and edema of cerebellar meninges and parenchyma due to a necrotizing vasculitis resulted in degeneration and necrosis of the gray and white matter. Few to numerous PCV2 DNA and antigen-bearing endothelial cells were detected in affected areas of the brain using in situ hybridization and immunohistochemistry. Conventional histochemical stains, as well as the detection of caspase 3 activity and DNA strand breaks by the terminal transferase dUTP nick end labeling assay, showed numerous apoptotic endothelial cells in the vascular lesions observed. Sequencing of various brain-derived PCV2-specific amplicons revealed a strong identity between different isolates and an 89 to 100% identity to previous isolates. The phylogenetic tree showed that there was no clustering of isolates correlating to clinical signs or geographic distribution. This previously undescribed PCV2-associated neurologic disease has features of both postweaning multisystemic wasting syndrome and, to a lesser extent, porcine dermatitis and nephropathy syndrome. The available evidence suggests that direct virus-induced apoptosis of endothelial cells plays a role in the pathogenesis of this unusual PCV2-associated cerebellar vasculitis.
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Affiliation(s)
- F A Seeliger
- Institute for Preclinical Drug Safety, ALTANA Pharma AG, Barsbuettel, Germany
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Finlaison D, Kirkland P, Luong R, Ross A. Survey of porcine circovirus 2 and postweaning multisystemic wasting syndrome in New South Wales piggeries. Aust Vet J 2007; 85:304-10. [PMID: 17685974 DOI: 10.1111/j.1751-0813.2007.00181.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine if postweaning multisystemic wasting syndrome (PMWS) is occurring in the New South Wales pig population and to determine the current and past seroprevalence of porcine circovirus 2 (PCV2). DESIGN Pig veterinarians were contacted seeking submission of tissues from animals with clinical signs suggestive of PMWS. Samples were also accepted from suspected cases of porcine dermatitis and nephropathy syndrome (PDNS). Serological studies were also undertaken on archival sera and sera submitted during the study. PROCEDURE Histopathological examination was undertaken on all tissues submitted. The presence of PCV2 was determined by immunohistochemistry. Sera were tested for PCV2 using a commercial enzyme linked immunosorbent assay kit modified for testing of serum samples. RESULTS No cases of PMWS were identified during the study. Four cases of PDNS were identified. PCV2 antibody was detected in 80% of archival sera from 1995 and 75.8% from 2001. Seroprevalence in samples tested during 2002-2003 was 87.8%. PCV2 was isolated from tissues of a case of PDNS. CONCLUSION PCV2 is widespread in the New South Wales pig population and has been since at least 1995. This study describes the first isolation of an Australian PCV2. No cases of PMWS were identified in New South Wales.
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Affiliation(s)
- D Finlaison
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, PMB 8, Camden NSW 2570, Australia
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Yang ZZ, Habib M, Shuai JB, Fang WH. Detection of PCV2 DNA by SYBR Green I-based quantitative PCR. J Zhejiang Univ Sci B 2007; 8:162-9. [PMID: 17323427 PMCID: PMC1810386 DOI: 10.1631/jzus.2007.b0162] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We developed an assay for the detection and quantitation of porcine circovirus type 2 (PCV2) with the SYBR Green I-based real-time PCR. The real-time PCR provides a broad dynamic range, detecting from 10(3) to 10(11) copies of DNA per reaction. No cross-reactions were found in specimens containing PCV1. Because of the high sensitivity and specificity of the assay with a relatively rapid and simple procedure, real-time PCR can be used as a routine assay for the clinical diagnosis of PCV2 infection. In this study we applied real-time PCR assay to 80 clinical samples, collected from 40 pigs with postweaning multisystemic wasting syndrome (PMWS) and 40 healthy pigs in comparison with conventional PCR assay. In 56 of 80 samples, PCV2 DNA was detected by conventional PCR assay. All samples positive for PCV2 DNA in conventional PCR assay were also positive in real-time assay, and 12 of 24 samples that tested negative for PCV2 DNA in the conventional assay were tested positive in real-time PCR assay. Real-time PCR assay increased the number of samples in which PCV2 was detected by 15%. It is, therefore, considered to be a useful tool for the detection of PCV2.
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Affiliation(s)
- Zong-zhao Yang
- Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029, China
- Hangzhou Husbandry and Veterinary Station, Hangzhou 310020, China
| | - Mudasser Habib
- Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029, China
| | - Jiang-bing Shuai
- Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029, China
| | - Wei-huan Fang
- Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029, China
- †E-mail:
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Abstract
AbstractPorcine circovirus type 2 (PCV2) is a member of the familyCircoviridae, a recently established virus family composed of small, non-enveloped viruses, with a circular, single-stranded DNA genome. PCV2, which is found all over the world in the domestic pig and probably the wild boar, has been recently associated with a number of disease syndromes, which have been collectively named porcine circovirus diseases (PCVD). Postweaning multisystemic wasting syndrome (PMWS), porcine dermatitis and nephropathy syndrome (PDNS) and reproductive disorders are the most relevant ones. Among them, only PMWS is considered to have a severe impact on domestic swine production. PMWS mainly affects nursery and/or fattening pigs; wasting is considered the most representative clinical sign in this disease. Diagnosis of this disease is confirmed by histopathological examination of lymphoid tissues and detection of a moderate to high amount of PCV2 in damaged tissues. Since PMWS is considered a multifactorial disease in which other factors in addition to PCV2 are needed in most cases to trigger the clinical disease, effective control measures have focused on the understanding of the co-factors involved in individual farms and the control or elimination of these triggers. PDNS, an immuno-complex disease characterized by fibrino-necrotizing glomerulonephritis and systemic necrotizing vasculitis, has been linked to PCV2, but a definitive proof of this association is still lacking. PCV2-associated reproductive disease seems to occur very sporadically under field conditions, but it has been characterized by late-term abortions and stillbirths, extensive fibrosing and/or necrotizing myocarditis in fetuses and the presence of moderate to high amounts of PCV2 in these lesions. Taking into account that scientific information on PCV2 and its associated diseases has been markedly expanded in the last 8 years, the objective of this review is to summarize the current state of knowledge of the most relevant aspects of PCV2 biology and PCVD.
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Affiliation(s)
- Joaquim Segalés
- Virology Department, Veterinary Research Laboratory, Veterinary Sciences Division, Stoney Road Stormont, DARDNI, Stormont, BT4 SD Belfast, Northern Ireland, UK.
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Opriessnig T, Janke BH, Halbur PG. Cardiovascular Lesions in Pigs Naturally or Experimentally Infected with Porcine Circovirus Type 2. J Comp Pathol 2006; 134:105-10. [PMID: 16325842 DOI: 10.1016/j.jcpa.2005.06.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Accepted: 06/28/2005] [Indexed: 10/25/2022]
Abstract
Abundant intracytoplasmic porcine circovirus type 2 (PCV2) was associated with myocardiocyte swelling or necrosis, or myocardial fibrosis (or both) in three naturally infected pigs aged 4-7 weeks from three different farms. One 6 week old pig from a fourth farm had severe diffuse segmental to circumferential lymphohistiocytic and plasmacytic periarteritis and endarteritis in several organs, PCV2 antigen was demonstrated in endothelial cells, and inflammatory cells in the arterial walls. In three pigs experimentally infected with PCV2, viral antigen was also associated with obliterated blood vessels in areas of granulomatous and necrotizing lymphadenitis. Together these findings suggest that the cardiovascular system in general and endothelial cells in particular play an important role in the pathogenesis of PCV2-associated diseases.
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Affiliation(s)
- T Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 South 16th Street, Ames, IA 50011, USA
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Cságola A, Kecskeméti S, Kardos G, Kiss I, Tuboly T. Genetic characterization of type 2 porcine circoviruses detected in Hungarian wild boars. Arch Virol 2005; 151:495-507. [PMID: 16328152 DOI: 10.1007/s00705-005-0639-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 08/16/2005] [Indexed: 11/24/2022]
Abstract
Porcine circoviruses (PCV) are present in pigs worldwide; they are grouped into two types: PCV1 comprising non-pathogenic viruses and PCV2 responsible for several clinical manifestations. Both types are frequently detected in domestic pigs, the prevalence and role of PCV in wild boars however, is not well studied. During the years 2002-2003 over 2000 organ samples of Hungarian wild boars were collected, grouped and samples from 307 different animals were tested by polymerase chain reaction for the presence of PCV. 35.5% of the wild boars were positive for one or both PCV types and PCV2 was detected in 20.5% of the animals. The PCV2 viruses were divided into 7 groups (WB-H1-7) based on sequencing data and genomes representing these groups were sequenced completely. The wild boar PCV2 groups were distributed evenly in the geographical region, regardless of the time and place of collection. The phylogenetic analysis of the PCV2 sequences of wild boar and domestic pig origin showed the possibility of an epidemiological link between wild boar and domestic pig infections. Interestingly, the complete nucleotide sequence of the viruses and the predicted amino acid sequence of the replication associated protein (ORF1) grouped the viruses similarly, whereas the capsid protein (ORF2) comparisons revealed different relations among the groups, suggesting the possibility of genomic recombination in PCV2.
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Affiliation(s)
- A Cságola
- Department of Microbiology and Infectious Diseases, Szent István University, Faculty of Veterinary Science, Budapest, Hungary
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Knell S, Willems H, Hertrampf B, Reiner G. Comparative genetic characterization of Porcine Circovirus type 2 samples from German wild boar populations. Vet Microbiol 2005; 109:169-77. [PMID: 16023798 DOI: 10.1016/j.vetmic.2005.06.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 05/12/2005] [Accepted: 06/02/2005] [Indexed: 11/19/2022]
Abstract
PCV-2 is involved in "postweaning multisystemic wasting syndrome" (PMWS), "porcine dermatitis and nephropathy syndrome" (PDNS), respiratory and reproductive disorders, and thereby plays a crucial role in today's swine production world-wide. The virus is apparently ubiquitous in domestic pigs and has also been demonstrated in wild pigs. Up to now, a characterization of PCV-2 samples from wild pigs, which might help to estimate the possible role of wild pigs as sources of domestic pig infection, has not been carried out. Spleen samples from 16 PCV-2-positive wild pigs from hunting grounds of four regions in Germany were used for the analysis of the viral genome. In one sample, the complete sequence of the genome was determined. In the other, a 742 nucleotide fragment from the highly variable capsid sequence of the ORF2 was sequenced. Analysis of the sequences led to the identification of three PCV-2 strains. One strain, representing 14 of the 16 samples, was closely related with Chinese, but not with German strains. The genome of this strain was shortened by one nucleotide by a deletion close to the end of ORF2. The deletion led to a shift of the stop-codon and to the insertion of a further codon. Two further strains differed in up to 4.7% of nucleotides and up to 10.5% of amino acids (aa). These strains were aligned with clusters of PCV-2 samples from mainly French and German domestic origin.
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Affiliation(s)
- Sebastian Knell
- Department of Swine Diseases, University of Giessen, Frankfurter Strasse 112, 35392 Giessen, Germany
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Sipos W, Duvigneau JC, Pietschmann P, Schilcher F, Hofbauer G, Hartl RT, Schmoll F. Porcine dermatitis and nephropathy syndrome (PDNS) is associated with a systemic cytokine expression profile indicative of proinflammation and a Th1 bias. Vet Immunol Immunopathol 2005; 107:303-13. [PMID: 15963571 DOI: 10.1016/j.vetimm.2005.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 05/11/2005] [Accepted: 05/12/2005] [Indexed: 11/26/2022]
Abstract
Porcine dermatitis and nephropathy syndrome (PDNS) is broadly discussed as a porcine circovirus type 2 (PCV2)-associated disease, although PCV2, in contrast to postweaning multisystemic wasting syndrome (PMWS), has to date not been proven to be the aetiologic agent. In order to better understand the complex immunopathology of PDNS, the systemic cytokine expression profiles of (i) five pigs suffering from PDNS, (ii) five animals suffering from naturally acquired PMWS and (iii) five controls were investigated at mRNA and protein levels by means of multiplex real-time RT-PCR and flow cytometric intracellular cytokine detection, respectively. IL-1alpha, IL-6 and IFN-gamma mRNA expressions were found to be elevated in PDNS pigs. At the protein level, an increased capacity of peripheral blood mononuclear cells to produce IL-2, IL-4, IL-6, IL-12, TNF-alpha and IFN-gamma was evident. Hematological investigations revealed a hypochromic anemia while basophils and monocytes were relatively and neutrophils absolutely increased in PDNS pigs. PCV2 antibody levels did not differ significantly between PDNS and PMWS affected animals. Taken results together, the cytokine profile of the PDNS affected animals together with hematological data pointed towards a proinflammatory condition supporting a Th1 bias. Cytokine data of PMWS affected animals exhibited only minor non-significant differences when compared to controls, only IL-10 was significantly decreased at the mRNA level.
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Affiliation(s)
- W Sipos
- Clinical Department for Farm Animals and Herd Management, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria.
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Ghebremariam MK, Gruys E. Postweaning Multisystemic Wasting Syndrome (PMWS) in pigs with particular emphasis on the causative agent, the mode of transmission, the diagnostic tools and the control measures. A review. Vet Q 2005; 27:105-16. [PMID: 16238110 DOI: 10.1080/01652176.2005.9695191] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
Postweaning multisystemic wasting syndrome (PMWS) is a worldwide emerging disease of weaned piglets. The objective of this review is to summarize the current knowledge regarding PMWS, its causative agent, mode of transmission, diagnostic techniques to detect PCV-2, the possible control measures, and the association of PMWS and PCV-2 with porcine dermatitis and nephropathy syndrome (PDNS). The causative agent of PMWS is porcine circovirus type 2 (PCV-2), however, not all pigs infected with PCV-2 develop the syndrome. PCV-2 is consistently associated with PMWS and PMWS is considered not to occur without it. Both the syndrome and the virus are not regarded as new. Co-factors that could activate PCV-2 to cause PMWS are considered. This enigmatic nature of both the syndrome and the virus is triggering a concern towards uncertainties of the viral transmission, its introduction in to the herd, effective tools of diagnosis, and control strategies.
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Affiliation(s)
- M K Ghebremariam
- Department of Pathobiology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
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Sørby R, Wien TN, Husby G, Espenes A, Landsverk T. Filter Function and Immune Complex Trapping in Splenic Ellipsoids. J Comp Pathol 2005; 132:313-21. [PMID: 15893989 DOI: 10.1016/j.jcpa.2004.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 11/24/2004] [Indexed: 11/29/2022]
Abstract
The role of splenic ellipsoids in the trapping of particulate material and immune complexes was investigated in mink (Mustela vison). The ellipsoids were prominent, with typical features such as a permeable endothelium and a discontinuous basement membrane surrounded by a sheath of macrophages and reticular cells. Ellipsoidal trapping of circulating particles was demonstrated 10 min after intracardiac injection of colloidal carbon and fluorescent microspheres. Preformed peroxidase-antiperoxidase immune complexes were detected in ellipsoids 10 min and also 1 h after intracardiac injection. Erythrocytes were frequently observed in the ellipsoidal sheath, and many phagocytized fragments of erythrocytes were found in the ellipsoidal macrophages. It was concluded that mink ellipsoids are effective blood filters with a role in retention of circulating particulate material, and that mammalian splenic ellipsoids also have the ability to trap immune complexes.
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Affiliation(s)
- R Sørby
- Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway
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