Porcine circoviruses: a minuscule yet mammoth paradox

2008 ◽  
Vol 10 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Sheela Ramamoorthy ◽  
Xiang-Jin Meng
Keyword(s):  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Weanling Pigs ◽  
Viral Pathogens ◽  
Pork Industry ◽  
The Usa ◽  
Lymphoid Depletion ◽  
Porcine Circoviruses

AbstractPorcine 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.

Molecular detection of porcine circo virus type 2 and porcine parvo virus inpigs having reproductive problems and histopathologicalstudies in the tissue of aborted pig foetuses

2016 ◽  
Author(s):  
S. R. Pegu ◽  
D. K. Sarma ◽  
S. Rajkhowa ◽  
M. Choudhury ◽  
D. Sarma ◽  
...  
Keyword(s):  
Molecular Detection ◽  
Infectious Agent ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Viral Pathogens ◽  
Lymphoid Depletion ◽  
Total Dna ◽  
Polymerase Chain ◽  
Kidney Liver

The present study was undertaken to detect the presence of porcine circovirus type 2 (PCV2) and porcine parvo virus (PPV) in 54 porcine aborted foetuses, stillborns and mummified foetuses. Foetal tissues of heart, lung, spleen and lymphnodes were used for extraction of total DNA and the presence of viral pathogens were confirmed through polymerase chain reaction (PCR) technique. Out of 54 samples, nine (16.6%) samples were positive for PCV2, eight (14.8%) samples were positive for PPV while co-infection with PCV2 and PPV was detected in four (7.4%) samples. The histopathological changes in the foetuses were found to be mostly necrosis in the cells of the developing organs viz. lungs, kidney, liver, heart, brain, spleen and lymphnodes. Lymphoid depletion was observed in the lymphoid follicles of the lymphnodes. Meningoencephalitis in the cerebrum was also seen in both PPV and PCV2 infected foetuses. The results indicated that PPV and PCV2 could be an important infectious agent in cases of porcine stillbirths, abortions and mummified foetuses.

Genetic diversity and prevalence of porcine circovirus type 3 (PCV3) and type 2 (PCV2) in the Midwest of the USA during 2016–2018

2020 ◽  
Vol 67 (3) ◽  
pp. 1284-1294 ◽  
Author(s):  
Yin Wang ◽  
Lance Noll ◽  
Nanyan Lu ◽  
Elizabeth Porter ◽  
Colin Stoy ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
The Usa ◽  
Type 3

scholarly journals Apoptosis in lymphoid organs of pigs naturally infected by porcine circovirus type 2

2004 ◽  
Vol 85 (10) ◽  
pp. 2837-2844 ◽  
Author(s):  
Ana R. Resendes ◽  
Natàlia Majó ◽  
Joaquim Segalés ◽  
Enric Mateu ◽  
Maria Calsamiglia ◽  
...  
Keyword(s):  
Lymph Node ◽  
Viral Load ◽  
B Cell ◽  
Inguinal Lymph Node ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus ◽  
Lymphoid Tissues ◽  
Lymphoid Depletion ◽  
Superficial Inguinal Lymph Node

The objective of the present study was to evaluate the involvement of apoptosis in the development of post-weaning multisystemic wasting syndrome (PMWS) lymphoid-depletion lesions. Twenty-one pigs that were categorized into three different lesional severity stages (S1, n=5; S2, n=7; S3, n=9) and five healthy control pigs (stage S0) were used. From all pigs, samples of thymus, spleen, tonsil, ileum and superficial inguinal lymph node were processed for histological examination, in situ hybridization for porcine circovirus type 2 (PCV2) detection and cleaved caspase-3 (CCasp3) immunohistochemistry for detection of apoptotic cells. PCV2 was quantified in serum samples by using TaqMan real-time PCR. CCasp3 labelling was measured in the different morphological compartments of all lymphoid tissues, using an automated system for quantification. Differences between each tissue compartment and lesional stage were assessed, as well as the correlation between apoptosis, lesional stage and viral load. Overall, the results indicated that the more intense the lymphoid depletion, the lower the rate of apoptosis. In the thymus, the cortex was the area where differences between PMWS-affected and control animals were more evident; it was found that all PMWS-affected pigs had significantly lower rates of apoptosis than the controls. In the secondary lymphoid organs, B-cell areas presented higher rates of apoptosis; similar apoptotic rates were found in this compartment in control and S1 pigs. In S2 and S3, B-cell areas were lost and the apoptotic pattern observed was a diffusely distributed low rate of positive cells. Significantly lower rates of apoptosis between PMWS-affected pigs and the control group were already evident in S1 for the thymus, spleen, superficial inguinal lymph node and Peyer's patches, but not for the tonsils. Apoptotic rates in lymphoid tissues were correlated inversely with viral load in serum and with severity of lesions. In conclusion, the results indicate that apoptosis is not a remarkable feature in PMWS lymphoid lesion development.

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 Whole-Genome Analysis of Porcine Circovirus Type 2 in Russia

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1631
Author(s):  
Sergei Raev ◽  
Anton Yuzhakov ◽  
Taras Aliper
Keyword(s):  
Genetic Diversity ◽  
Genome Analysis ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Whole Genome ◽  
Whole Genome Analysis ◽  
Reading Frame

Porcine circovirus type 2 (PCV2) is the causative agent of porcine circovirus-associated diseases (PCVAD) that bring about significant economic losses in the pig industry all over the world. The aim of this study was to investigate the genetic diversity of PCV2 in Russia and characterize the available complete genome sequences. PCV2 DNA was detected at all investigated farms located in different regions of Russia. Whole-genome analysis demonstrated that the majority of PCV2 strains belonged to genotype PCV2d (12 out of 14), while PCV2a and PCV2b were only detected at 2 farms (one at each). Further analysis revealed that all antibody recognition sites in Russian PCV2 strains were different from the corresponding epitopes in a PCV2a vaccine strain, suggesting that PCV2a-based vaccines may only provide limited protection against these strains. PCV2d strains could be grouped into 3 distinct lines which shared 98.7–100% identity within open reading frame 2 (ORF2). It is the first study reporting the genetic diversity of PCV2 strains in Russia. Our data indicated that, similarly to China, Europe, and USA, PCV2a and PCV2b have largely been replaced by PCV2d.

scholarly journals Macrophage Polarization Modulated by Porcine Circovirus Type 2 Facilitates Bacterial Coinfection

2021 ◽  
Vol 12 ◽  
Author(s):  
Wen Zhang ◽  
Zhendong Fu ◽  
Hongyan Yin ◽  
Qingbing Han ◽  
Wenhui Fan ◽  
...  
Keyword(s):  
Macrophage Polarization ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Pcv2 Infection ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Target Cells ◽  
M2 Macrophage ◽  
Bacterial Coinfection

Polarization of macrophages to different functional states is important for mounting responses against pathogen infections. Macrophages are the major target cells of porcine circovirus type 2 (PCV2), which is the primary causative agent of porcine circovirus–associated disease (PCVAD) leading to immense economic losses in the global swine industry. Clinically, PCV2 is often found to increase risk of other pathogenic infections yet the underlying mechanisms remain to be elusive. Here we found that PCV2 infection skewed macrophages toward a M1 status through reprogramming expression of a subset of M1-associated genes and M2-associated genes. Mechanistically, induction of M1-associated genes by PCV2 infection is dependent on activation of nuclear factor kappa B (NF-κB) and c-jun N-terminal kinase (JNK) signaling pathways whereas suppression of M2-associated genes by PCV2 is via inhibiting expression of jumonji domain containing-3 (JMJD3), a histone 3 Lys27 (H3K27) demethylase that regulates M2 activation of macrophages. Finally, we identified that PCV2 capsid protein (Cap) directly inhibits JMJD3 transcription to restrain expression of interferon regulatory factor (IRF4) that controls M2 macrophage polarization. Consequently, sustained infection of PCV2 facilitates bacterial infection in vitro. In summary, these findings showed that PCV2 infection functionally modulated M1 macrophage polarization via targeting canonical signals and epigenetic histone modification, which contributes to bacterial coinfection and virial pathogenesis.

scholarly journals Genomic Rearrangement and Recombination of Porcine Circovirus Type 2 and Porcine Circovirus-Like Virus P1 in China

2021 ◽  
Vol 8 ◽  
Author(s):  
Libin Wen ◽  
Kongwang He
Keyword(s):  
Genome Rearrangement ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Protein Coding ◽  
Generic Term

Porcine circovirus type 2 (PCV2) belongs to the genus Circovirus of the family Circoviridae, and it has been associated with porcine circovirus (associated) disease (PCVD or PCVAD) in pigs. PCVAD is the generic term for a series of disease syndromes that have caused economic losses to the pig industry worldwide. Since the discovery of PCV2 in the late 1990s, the virus has continued to evolve, and novel genotypes have continued to appear. Moreover, there has been recombination between different genotypes of PCV2. This review attempts to illustrate some progress concerning PCV2 in genome rearrangement and genomic recombination with non-PCV2-related nucleic acids, particularly focusing on the porcine circovirus-like virus P1 formed by the recombination of PCV2. The presence of rearranged PCV2 genomes can be demonstrated both in vivo and in vitro, and these subviral molecules ranged from 358 to 1,136 bp. Depending on whether it has the ability to encode a protein, the agents formed by PCV2 recombination can be divided into two categories: porcine circovirus-like viruses and porcine circovirus-like mini agents. We mainly discuss the porcine circovirus-like virus P1 regarding genomic characterization, etiology, epidemiology, and pathogenesis. Further research needs to be conducted on the pathogenicity of other porcine circovirus-like viruses and porcine circovirus-like mini agents and the effects of their interactions with PCV2, especially for the porcine circovirus-like mini agents that do not have protein-coding functions in the genome.

scholarly journals DETECTION OF PORCINE CIRCOVIRUS TYPE 3 IN RUSSIAN PIG HOLDINGS

2019 ◽  
pp. 29-33
Author(s):  
M. V. Biryuchenkova ◽  
A. M. Timina ◽  
A. V. Shcherbakov
Keyword(s):  
Russian Federation ◽  
Clinical Manifestations ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Unknown Etiology ◽  
The Russian Federation ◽  
Type 3

Diseases associated with porcine circoviruses (mainly with porcine circovirus type 2) have various manifestations, are common in pigs in countries having well-developed pig industry and responsible for significant economic losses. Porcine circovirus type 3 (PCV-3) causing systemic inflammation of unknown etiology in animals was detected the USA in 2015. Later, data on PCV-3 detection in Asia, Europe and South America were published. Analysis of literature data on current epidemic situation on PCV-3 infection in foreign countries as well as the disease clinical manifestations and postmortem lesions are described. Results of molecular and genetic tests of biomaterials collected from pigs in 51 holdings located in 28 regions of the Russian Federation are presented. A total of 280 samples of biological materials of different types (organs, tissues, stillborn piglets) collected from domestic pigs with respiratory, reproductive and neurological disorders, dermatitis and from emaciated pigs were tested and PCV-3 genome was detected in 11 samples from 9 holdings located in 5 regions of the Russian Federation. Porcine circovirus type 3 was detected in lung, bronchial and mediastinal lymph node, spleen tissues from grower and fattening piglets, adult pigs and aborted fetuses. Samples that were positive for PCV-3 DNA when tested with molecular methods (PCR, real-time PCR) were tested for other pathogens. The following pathogens were also detected in 6 out of 11 samples (55%): Actinobacillus pleuropneumoniae, Mycoplasma hyorhinis, Streptococcus suis, Haemophilus parasuis, Mycoplasma hyopneumoniae and Pasteurella multocida. Porcine circovirus type 2 was detected in one sample. Presented test results are indicative of probable combined etiology of respiratory and reproductive disorders in tested pigs that results in various clinical manifestations. Grower and fattening piglets were found to be the most susceptible to PCV-3-associated disease. Further studies are required for identification of actual PCV-3 pathogenicity and its prevalence in the territory of the Russian Federation.

scholarly journals Genetic Diversity and Prevalence of Porcine Circovirus Type 2 in China During 2000-2019

2021 ◽  
Vol 8 ◽  
Author(s):  
Ning Li ◽  
Jing Liu ◽  
Jiali Qi ◽  
Feng Hao ◽  
Lei Xu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Wide Distribution ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Amino Acid Sequences ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Swine Industry ◽  
Emerging Virus

As the major pathogen for porcine circovirus-associated disease (PCVAD), porcine circovirus type 2 (PCV2) is no longer treated as an emerging virus anymore. The wide distribution of PCV2 infection in China causes huge economic losses in the swine industry. Currently, it is generally believed that PCV2 has eight genotypes (PCV2a to PCV2h), with PCV2a, PCV2b, and PCV2d being widely distributed. To comprehensively explore the genetic diversity and prevalence of PCV2 in China, PCV-2 sequences submitted from China in the GenBank database were retrieved. With a total of 714 PCV2 strains were retrieved, we found that early-submitted PCV2 sequences were mainly collected from coastal provinces in the southeast part of China, which may indicate PCV2 was initially circulating in those regions. From 2002 to 2008, PCV2b was the dominant prevalent genotype in those retrieved sequences. From 2009, PCV2d became the dominant genotype in those sequences, dropping a hint that a potential shift of PCV2b to PCV2d might occur in 2009, which is similar to the patterns at the global level. In addition to the PCV2a, PCV2b, and PCV2d genotypes, novel strains were also characterized. We further revealed that the amino acid sequences consistency of PCV2a Cap is higher than those in other genotypes. Together, this study provided clues for the possible prevalent genotypes and dynamics of genetic diversity in China from 2000 to 2019.

scholarly journals A Slaughterhouse Survey for Porcine Circovirus Type 2 in Commercial Pigs in Ibadan, Southwest Nigeria

2018 ◽  
Vol 62 (2) ◽  
pp. 30-34 ◽  
Author(s):  
C. O. Aiki-Raji ◽  
A. I. Adebiyi ◽  
D. O. Oluwayelu
Keyword(s):  
Control Strategies ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Economic Losses ◽  
Carrier Status ◽  
Swine Industry ◽  
Southwest Nigeria ◽  
Swine Disease

Abstract Porcine circovirus type 2 (PCV2) is recognized as one of the most important agents of reproductive disorders in gilts and sows worldwide. It is associated with considerable economic losses in the swine industry due to the unthriftiness, and variable morbidity and mortality it causes in pigs. In spite of the devastation caused by this virus to the global pig industry, there is little or no report of its occurrence in Nigeria. Hence, a slaughterhouse based survey was conducted to determine the prevalence of PCV2 infections in pigs in Ibadan, southwest Nigeria. Using a commercial ELISA kit, 364 pig sera collected from a major abattoir were screened for IgG antibodies against PCV2. The overall prevalence of anti-PCV2 antibodies in the pigs was 1.4 % (5/364), with more female pigs (4/237, 1.7 %) being seropositive than males (1/127, 0.8 %). Since there is no routine vaccination against this swine disease in Nigeria, thus the antibodies detected in the pig sera indicated a natural exposure to the virus. The absence of clinical disease in the pigs also suggests the possibility of a carrier status for these animals and shows that they could serve as hosts for the perpetuation of the disease. These findings underscore the need for continuous surveillance for PCV2 among pigs in Nigeria in order to determine its contribution to production losses incurred in the Nigerian swine industry and aid the development of prevention and control strategies against the disease.

Sign in / Sign up

Export Citation Format

Share Document