scholarly journals Cloned Genomic DNA of Type 2 Porcine Circovirus Is Infectious When Injected Directly into the Liver and Lymph Nodes of Pigs: Characterization of Clinical Disease, Virus Distribution, and Pathologic Lesions

2002 ◽  
Vol 76 (2) ◽  
pp. 541-551 ◽  
Author(s):  
M. Fenaux ◽  
P. G. Halbur ◽  
G. Haqshenas ◽  
R. Royer ◽  
P. Thomas ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Plasmid Dna ◽  
Genomic Dna ◽  
Clinical Signs ◽  
Porcine Circovirus ◽  
Live Virus ◽  
Virus Stock ◽  
Molecular Clone ◽  
Pathologic Lesions

ABSTRACT Infection of animals with a molecular viral clone is critical to study the genetic determinants of viral replication and virulence in the host. Type 2 porcine circovirus (PCV2) has been incriminated as the cause of postweaning multisystemic wasting syndrome (PMWS), an emerging disease in pigs. We report here for the first time the construction and use of an infectious molecular DNA clone of PCV2 to characterize the disease and pathologic lesions associated with PCV2 infection by direct in vivo transfection of pigs with the molecular clone. The PCV2 molecular clone was generated by ligating two copies of the complete PCV2 genome in tandem into the pBluescript SK (pSK) vector and was shown to be infectious in vitro when transfected into PK-15 cells. Forty specific-pathogen-free pigs at 4 weeks of age were randomly assigned to four groups of 10 each. Group 1 pigs served as uninoculated controls. Pigs in group 2 were each inoculated intranasally with about 1.9 × 105 50% tissue culture infective doses of a homogeneous PCV2 live virus stock derived from the molecular clone. Pigs in group 3 were each injected intrahepatically with 200 μg of the cloned PCV2 plasmid DNA, and pigs in group 4 were each injected into the superficial iliac lymph nodes with 200 μg of the cloned PCV2 plasmid DNA. Animals injected with the cloned PCV2 plasmid DNA developed infection resembling that induced by intranasal inoculation with PCV2 live virus stock. Seroconversion to PCV2-specific antibody was detected in the majority of pigs from the three inoculated groups at 35 days postinoculation (DPI). Viremia, beginning at 14 DPI and lasting 2 to 4 weeks, was detected in the majority of the pigs from all three inoculated groups. There were no remarkable clinical signs of PMWS in control or any of the inoculated pigs. Gross lesions in pigs of the three inoculated groups were similar and were characterized by systemically enlarged, tan lymph nodes and lungs that failed to collapse. Histopathological lesions and PCV2-specific antigen were detected in numerous tissues and organs, including brain, lung, heart, kidney, tonsil, lymph nodes, spleen, ileum, and liver of infected pigs. This study more definitively characterizes the clinical course and pathologic lesions exclusively attributable to PCV2 infection. The data from this study indicate that the cloned PCV2 genomic DNA may replace infectious virus for future PCV2 pathogenesis and immunization studies. The data also suggest that PCV2, although essential for development of PMWS, may require other factors or agents to induce the full spectrum of clinical signs and lesions associated with advanced cases of PMWS.

scholarly journals A Chimeric Porcine Circovirus (PCV) with the Immunogenic Capsid Gene of the Pathogenic PCV Type 2 (PCV2) Cloned into the Genomic Backbone of the Nonpathogenic PCV1 Induces Protective Immunity against PCV2 Infection in Pigs

2004 ◽  
Vol 78 (12) ◽  
pp. 6297-6303 ◽  
Author(s):  
M. Fenaux ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
F. Elvinger ◽  
X. J. Meng
Keyword(s):  
Lymph Nodes ◽  
Protective Immunity ◽  
Intramuscular Injection ◽  
Porcine Circovirus ◽  
Lymphoid Tissues ◽  
Wild Type ◽  
Live Virus ◽  
Group 4 ◽  
Group 1

ABSTRACT Porcine circovirus type 2 (PCV2) is associated with postweaning multisystemic wasting syndrome in pigs, whereas PCV1 is nonpathogenic. We previously demonstrated that a chimeric PCV1-2 virus (with the immunogenic capsid gene of PCV2 cloned into the backbone of PCV1) induces an antibody response to the PCV2 capsid protein and is attenuated in pigs. Here, we report that the attenuated chimeric PCV1-2 induces protective immunity to wild-type PCV2 challenge in pigs. A total of 48 specific-pathogen-free piglets were randomly and equally assigned to four groups of 12 pigs each. Pigs in group 1 were vaccinated by intramuscular injection with 200 μg of the chimeric PCV1-2 infectious DNA clone. Pigs in group 2 were vaccinated by intralymphoid injection with 200 μg of a chimeric PCV1-2 infectious DNA clone. Pigs in group 3 were vaccinated by intramuscular injection with 103.5 50% tissue culture infective doses (TCID50) of the chimeric PCV1-2 live virus. Pigs in group 4 were not vaccinated and served as controls. By 42 days postvaccination (DPV), the majority of pigs had seroconverted to PCV2 capsid antibody. At 42 DPV, all pigs were challenged intranasally and intramuscularly with 2 × 104.5 TCID50 of a wild-type pathogenic PCV2 virus. By 21 days postchallenge (DPC), 9 out of the 12 group 4 pigs were viremic for PCV2. Vaccinated animals in groups 1 to 3 had no detectable PCV2 viremia after challenge. At 21 DPC the lymph nodes in the nonvaccinated pigs were larger (P < 0.05) than those of vaccinated pigs. The PCV2 genomic copy loads in lymph nodes were reduced (P < 0.0001) in vaccinated pigs. Moderate amounts of PCV2 antigen were detected in most lymphoid tissues of nonvaccinated pigs but in only 1 of 36 vaccinated pigs. Mild-to-severe lymphoid depletion and histiocytic replacement were detected in lymphoid tissues in the majority of nonvaccinated group 4 pigs but in only a few vaccinated group 1 to 3 pigs. The data from this study indicated that when given intramuscularly in pigs, the attenuated chimeric PCV1-2 live virus, as well as the chimeric PCV1-2 infectious DNA clone, induces protective immunity against PCV2 infection and could potentially serve as an effective vaccine.

scholarly journals Vaccination with a Porcine Reproductive and Respiratory Syndrome (PRRS) Modified Live Virus Vaccine Followed by Challenge with PRRS Virus and Porcine Circovirus Type 2 (PCV2) Protects against PRRS but Enhances PCV2 Replication and Pathogenesis Compared to Results for Nonvaccinated Cochallenged Controls

2015 ◽  
Vol 22 (12) ◽  
pp. 1244-1254 ◽  
Author(s):  
Megan C. Niederwerder ◽  
Bhupinder Bawa ◽  
Nick V. L. Serão ◽  
Benjamin R. Trible ◽  
Maureen A. Kerrigan ◽  
...  
Keyword(s):  
Average Daily Gain ◽  
Disease Model ◽  
Clinical Signs ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Live Virus ◽  
Pcv2 Replication

ABSTRACTCoinfections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early postchallenge period, the number of pigs with PRRSV-associated clinical signs was decreased, and average daily gain (ADG) was increased, in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later postchallenge period, more pigs in the vaccinated group showed increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD.

scholarly journals Diagnosis of post-weaning multisystemic wasting syndrome in pigs in Brazil caused by porcine circovirus type 2

2003 ◽  
Vol 55 (5) ◽  
pp. 522-527 ◽  
Author(s):  
J.R. Ciacci-Zanella ◽  
N. Morés
Keyword(s):  
Clinical Signs ◽  
Rflp Analysis ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Nested Polymerase Chain Reaction ◽  
Wasting Syndrome ◽  
Thymus Atrophy ◽  
Granulomatous Lymphadenitis

This report describes the first preliminary characterization of porcine circovirus type 2 (PCV2) isolates from pigs affected with post-weaning multisystemic wasting syndrome (PMWS) in Brazil. Diseased pigs were examined at necropsy and by histopathology. Macroscopic and microscopic analyses revealed lesions reported to be typical of PMWS, which included, respectively, emaciation, enlargement of lymph nodes, thymus atrophy and interstitial pneumonia, and granulomatous lymphadenitis with syncytial cells, among others. Using nested polymerase chain reaction (PCR) or imunoperoxidase it was possible to detected DNA or antigen of PCV2, respectively. The PCR' s amplified fragment could be differentiated from PCV1 and PCV2 from one another by restriction fragment length polymorphism (RFLP) analysis. PCV2 DNA was detected in 70% (14/20) of samples of pigs with clinical signs and lesions associated with PMWS. This study shows that PCV2 is associated with lesions and symptoms indicative of PMWS in pigs. It is also shown that the Brazilian PCV2 isolates may have variation in their genome.

scholarly journals Targeted Alteration of Antibody-Based Immunodominance Enhances the Heterosubtypic Immunity of an Experimental PCV2 Vaccine

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 506
Author(s):  
AGM Rakibuzzaman ◽  
Oleksandr Kolyvushko ◽  
Gagandeep Singh ◽  
Peter Nara ◽  
Pablo Piñeyro ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Infectious Clone ◽  
Clinical Signs ◽  
Porcine Circovirus Type ◽  
Antibody Responses ◽  
Porcine Circovirus ◽  
Pcv2 Vaccine ◽  
Heterosubtypic Immunity ◽  
Weanling Piglets

Despite the availability of commercial vaccines which can effectively prevent clinical signs, porcine circovirus type 2 (PCV2) continues to remain an economically important swine virus, as strain drift, followed by displacement of new subtypes, occurs periodically. We had previously determined that the early antibody responses to the PCV2 capsid protein in infected pigs map to immunodominant but non-protective, linear B cell epitopes. In this study, two of the previously identified immunodominant epitopes were mutated in the backbone of a PCV2b infectious clone, to rationally restructure the immunogenic capsid protein. The rescued virus was used to immunize 3-week-old weanling piglets, followed by challenge with a virulent heterologous PCV2d strain. As expected, immunodominant antibody responses to the targeted epitopes were abrogated in vaccinated pigs, while a broadening of the virus neutralization responses was detected. Vaccinated pigs were completely protected against challenge viral replication, had reduced microscopic lesions in lymphoid organs and gained significantly more body weight when compared to unvaccinated pigs. Thus, the experimental PCV2 vaccine developed was highly effective against challenge, and, if adopted commercially, can potentially slow down or eliminate new strain creation.

scholarly journals Epizootic Disseminated Toxoplasmosis in Captive Slender-tailed Meerkats (Suricata suricatta)

1997 ◽  
Vol 34 (1) ◽  
pp. 1-7 ◽  
Author(s):  
C. Juan-Sallés ◽  
N. Prats ◽  
S. López ◽  
M. Domingo ◽  
A. J. Marco ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Neospora Caninum ◽  
Clinical Signs ◽  
Giant Cells ◽  
Mesenteric Lymph Nodes ◽  
Suricata Suricatta ◽  
Mesenteric Lymph ◽  
Clinicopathologic Findings ◽  
Foamy Macrophages

Fatal disseminated toxoplasmosis was diagnosed in seven captive slender-tailed meerkats ( Suricata suricatta) according to clinicopathologic findings and immunohistochemistry. Five of nine meerkats died during an outbreak in late 1994. These included four kits (2.5 to 4.5 months old) and a 4-year-old meerkat. Two other meerkats, both adults, died in 1992 and 1995. Respiratory insufficiency (4/7) and incoordination (3/7) were the most consistent clinical signs, although two of seven meerkats died unexpectedly. At necropsy, the lungs were reddened and noncollapsed (6/7), and had multiple pale round foci (4/7). Yellow foci of necrosis in mesenteric lymph nodes (4/7), splenomegaly (3/7), and hydropericardium (3/7) were other common gross findings. Microscopically, interstitial pneumonia was present in all seven meerkats, being acute to subacute in six of them. Type 2 pneumocyte hyperplasia, aggregates of foamy macrophages, and giant cells were consistently seen. Multifocal to locally extensive necrosis of mesenteric lymph nodes (4/7), mild to severe multifocal necrotizing hepatitis (5/6), and mild nonsuppurative encephalitis (4/6) were also seen. Toxoplasma-like organisms were consistently associated with these lesions and were stained by the avidin biotin peroxidase procedure with an antiserum that does not cross-react with Neospora caninum. Meerkats were most likely infected after an oral, primary exposure to Toxoplasma. Several observations indicate that meerkats may be highly susceptible to toxoplasmosis.

scholarly journals Granulomatous Necrotizing Myositis in Swine Affected by Porcine Circovirus Disease

2017 ◽  
Vol 55 (2) ◽  
pp. 268-272 ◽  
Author(s):  
Guilherme Konradt ◽  
Raquel A. S. Cruz ◽  
Daniele M. Bassuino ◽  
Matheus V. Bianchi ◽  
Caroline P. de Andrade ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Clinical Signs ◽  
Giant Cells ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Lower Amount ◽  
Clinical Syndromes ◽  
Necrotizing Myositis ◽  
Polymerase Chain

Porcine circovirus type 2 (PCV2) is associated with multiple clinical syndromes in pigs, known as porcine circovirus diseases. This work describes an outbreak of porcine circovirus diseases with severe lesions affecting the skeletal muscle. Ninety-two pigs had apathy, weight loss, and diarrhea over a clinical course of 7 to 10 days. Approximately 30 of the pigs had stiff gait, muscle weakness, hind limb paresis, and recumbency. Twelve of the 92 pigs were necropsied, and 4 had pale discoloration of skeletal muscles with microscopic lesions of granulomatous necrotizing myositis. Immunohistochemistry of skeletal muscle showed that PCV2 antigen was located primarily in the cytoplasm and nuclei of macrophages, lymphocytes, and multinucleated giant cells, with a lower amount in the cytoplasm of endothelial cells, necrotic fibers, and satellite cells. Affected muscle samples were polymerase chain reaction–positive for PCV2 and the amplicon exhibited 99% identity with sequences belonging to the PCV2b genotype. Locomotor clinical signs and granulomatous necrotizing myositis should be considered as another expression of PCV2 infection in pigs.

scholarly journals Porcine Circovirus Type 2 Infection Decreases the Efficacy of a Modified Live Porcine Reproductive and Respiratory Syndrome Virus Vaccine

2006 ◽  
Vol 13 (8) ◽  
pp. 923-929 ◽  
Author(s):  
T. Opriessnig ◽  
N. E. McKeown ◽  
K. L. Harmon ◽  
X. J. Meng ◽  
P. G. Halbur
Keyword(s):  
Age Groups ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Pcv2 Infection ◽  
Daily Weight Gain ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Live Virus ◽  
Lymphoid Depletion

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV)-induced pneumonia is a major problem, and vaccination is used to reduce losses associated with PRRSV. Porcine circovirus type 2 (PCV2) causes lymphoid depletion, and there is concern that this adversely affects the immune response. The objective of this study was to investigate the effect of PCV2 infection on the efficacy of modified live virus (MLV) PRRSV vaccine. Sixty-nine 2-week-old pigs were randomly assigned to one of seven groups of 9 to 10 pigs each. At 6 weeks of age, pigs in groups 4, 5, and 6 were inoculated intranasally with PCV2 ISU-40895. At 8 weeks of age, groups 3, 4, 6, and 7 were vaccinated with a PRRSV MLV vaccine. At 12 weeks of age, groups 2, 3, and 4 were challenged with PRRSV SDSU73. All pigs were necropsied 14 days after PRRSV challenge. PCV2-infected, PRRSV-vaccinated, and PRRSV-challenged pigs had significantly (P < 0.05) more-severe macroscopic lung lesions than did the PRRSV-vaccinated and PRRSV-challenged pigs that were not exposed to PCV2 prior to PRRSV vaccination. Nonvaccinated PRRSV-infected pigs had a significantly (P < 0.001) higher incidence of PRRSV antigen in lungs than did all other groups except the group infected with PCV2 prior to PRRSV vaccination and challenge. The nonvaccinated PRRSV-challenged group and the group challenged with PCV2 prior to PRRSV vaccination and challenge had significantly (P < 0.001) lower average daily weight gain than did the control and the vaccinated groups. This work suggests that PCV2 infection has an adverse effect on the development of protective immunity induced by PRRSV vaccine.

scholarly journals Intestinal lesions in pigs affected with postweaning multisystemic wasting syndrome

2008 ◽  
Vol 28 (6) ◽  
pp. 313-318 ◽  
Author(s):  
Priscila Zlotowski ◽  
André M.R. Corrêa ◽  
David E.S.N. Barcellos ◽  
Cláudio E.F. Cruz ◽  
William Asanome ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Villous Atrophy ◽  
Clinical Signs ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Porcine Circovirus ◽  
Mesenteric Lymph Nodes ◽  
Salmonella Spp ◽  
Wasting Syndrome ◽  
Mesenteric Lymph ◽  
Intestinal Lesions

Samples of mesenteric lymph nodes and intestines from 79 unthrifty 3- to 5-month-old postweaning pigs, confirmed as naturally affected with postweaning multisystemic wasting syndrome (PMWS), were studied. Pigs originated from 12 farms in southern Brazil and were selected on the basis of clinical signs and/or gross lesions suggestive of enteric disorder. Lymphohistiocytic infiltrates of varying intensity were associated with anti-porcine circovirus type 2 (anti-PCV2) immunostaining (IS) in samples of intestines and mesenteric lymph nodes from all pigs. Although most findings were similar to those described in PCV2-associated enteritis, anti-PCV2 IS in association with depletion of the goblet cell mucin stores (24 pigs), diffuse ileal villous atrophy and fusion (18 pigs), and dilatation of the lymphatic vessels (11 pigs) combined or not with lymphangitis were also observed. PCV2 antigen was immunohistochemically demonstrated in the cytoplasm and nuclei from intralesional epithelial cells, histiocytes, and endothelial-like cells in intestinal tissues. Together these findings imply an association with PCV2. The presence of co-infections by Lawsonia intracellularis, Brachyspira spp., Mycobacterium spp., Salmonella spp., rotavirus, parvovirus, coronavirus and enteric calicivirus with PCV2 in the intestinal lesions was investigated.

Porcine circovirus type 2 and associated diseases in Romania — Short communication

2007 ◽  
Vol 55 (1) ◽  
pp. 151-156 ◽  
Author(s):  
D. Cadar ◽  
A. Cságola ◽  
Á. Dán ◽  
Z. Deim ◽  
Marina Spînu ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Porcine Circovirus Type ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Associated Diseases ◽  
Wasting Syndrome

Porcine circovirus type 2 (PCV2) has been demonstrated to be the causal agent for postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). This report describes the first detection of PCV2 and associated diseases in a Romanian swine herd located in Transylvania. The clinical signs, pathological and histopathological changes observed in affected pigs were similar to those previously described for PDNS and PMWS. Polymerase chain reaction and in situ hybridisation were used for the detection of PCV2 nucleic acids from tissues and serum samples. Complete PCV2 genomes of both PMWS and PDNS cases were sequenced and analysed, and by comparing them with each other no genomic differences could be detected. The sequence analysis showed that the Romanian PCV2 was closely related to PCV2 identified in France and in Hungary.

scholarly journals Rectal stenosis in pigs associated with Salmonella Typhimurium and porcine circovirus type 2 (PCV2) infection

2011 ◽  
Vol 31 (6) ◽  
pp. 511-515 ◽  
Author(s):  
Tatiane Terumi Negrão Watanabe ◽  
Priscila Zlotowski ◽  
Luiz Gustavo Schneider de Oliveira ◽  
Verônica Machado Rolim ◽  
Marcos José Pereira Gomes ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Large Intestine ◽  
Rectal Wall ◽  
Clinical Signs ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Rectal Stricture ◽  
Rectal Stenosis

Rectal stricture is an acquired annular fibrous constriction of the rectum that results from a variety of chronic necrotizing enteric diseases. In pigs, it is in most cases a sequel of Salmonella infection. Porcine circovirus type 2 (PCV2) is a known pathogen causing immunosuppression in pigs worldwide. PCV2 infected pigs may be predisposed to salmonellosis. In this report, rectal stenosis was observed in 160 pigs from a herd that experienced an outbreak of enteric salmonellosis over a 4-month period. Distension of the abdominal wall and diarrhea were the main clinical signs observed. Five animals were analyzed showing annular cicatrization of the rectal wall 5.0-7.0 cm anterior to the anorectal junction and Salmonella-positive immunostaining in the large intestine. Salmonella Typhimurium was isolated from fragments of the large intestine. Porcine circovirus type 2 antigen was observed in the mesenteric lymph-node in 4 pigs and in the large intestine in 3 pigs.

Sign in / Sign up

Export Citation Format

Share Document