This study was focused on the genotyping and quantification of Porcine circovirus type 2 (PCV2) in thirty PCV2-positive pigs with different clinical symptoms (PCV2-infected without wasting, PCV2-infected with wasting, PCV2-infected with wasting and lymphoid depletion). The quantity of PCV2 DNA in diverse tissues was significantly differed among these groups. (One-way ANOVA test, p < 0.001) Interestingly, PCV2-DNA load in tissues of PCV2-infected pigs without wasting and PCV2-infected pigs with wasting and lymphoid depletion were not significantly differed (p = 0.38), while they were all significantly higher when compared with PCV2-infected pigs with wasting-only. PCV2 DNA quantity in tissues was significantly higher in PCV2a and 2b co-infected pigs compared to the PCV2b only-infected pigs (Wilcoxon test, p = 0.039). The PCV2a and 2b co-infected pigs had increased wasting and lymphoid depletion rate but it was not statistically significant. Therefore, this cross-sectional study suggested that PCV2 DNA load in tissues was diverse by clinical and histological findings. Furthermore, co-infection of PCV2a and 2b affected to the PCV2 DNA load in tissues with increased rate of wasting and lymphoid depletion.
Circovirus ; Coinfection ; Cross-Sectional Studies ; DNA ; Genotype ; Swine

Porcine circovirus type 2 (PCV2) can cause immunosuppression on herds. PCV2, as an essential pathogen of PCV2-systemic disease (PCV2-SD), has caused considerable economic losses in pig industry worldwide. Here we review and address the evolution, viral protein and immunolesion of PCV2 and preventive techniques of PCV2-SD.
Animals ; Circoviridae Infections ; veterinary ; Circovirus ; genetics ; Phylogeny ; Swine ; Swine Diseases ; virology ; Viral Proteins ; genetics

A pair of primers with BamH I restriction site were designed to amplify the complete genome of goose circovirus. Two copies of the genome were ligated in tandem and cloned into pGEM-T Easy vector to construct an infectious clone named as pGEMT-2GoCV. The pGEMT-2GoCV linearized with EcoR I was transfected to negative embryos and gosling with Lipfectamine. PCR detection verified the proliferation of GoCV in geese. Some sera of the embryo transfected group were detected to be positive at 2 and 4 weeks after hatching and one bursa was detected to be positive at 4 weeks. Some sera of the gosling transfected group were also detected to be positive at 2 weeks after transfection. Furthermore, the mark in the PCR products were identified by BamH I digestion and the GoCV in positive tissue and sera were quantitated by Real-time PCR. The results showed that the virus load in positive bursa was 1.57 x 10(6) copies/mg, the virus load in positive sera were 3.52 x 10(4)-5.92 x 10(5) copies/microL. In conclusion, the infectious DNA clone constructed with two copies of full-length GoCV genome in tandem can transfect embryo and gosling and propagate the marked goose circovirus.
Animals ; Circovirus ; genetics ; Geese ; virology ; Real-Time Polymerase Chain Reaction ; Transfection

The capsid protein of porcine circovirus type 2 (PCV2) encoded by open reading frame 2 (ORF2) is important for neutralizing activity against PCV2 infection. This study investigated the heterogeneity of the ORF2 gene of PCV2 isolated in Korea during 2016–2017. The results revealed that PCV2d is currently the predominant genotype. Moreover, comparison of ORF2 from 17 PCV2 isolates revealed 88.3–100% homology at the nucleotide (deduced amino acid 86.3–100%) level. Interestingly, 61.5% (8/13) of the PCV2d isolates had glycine at position 210. These data provide a useful information for PCV2 epidemiology in Korea.
Capsid Proteins ; Circovirus ; Epidemiology ; Genetic Variation ; Genotype ; Glycine ; Korea ; Open Reading Frames ; Population Characteristics

A novel porcine circovirus 3 (PCV3) was first detected in pigs showing porcine dermatitis and nephropathy syndrome, reproductive failure, and multisystemic inflammation in the USA. Herein, we report on PCV3 as a potential etiological agent of clinical signs, reproductive failure and respiratory distress on Korean pig farms, based on in situ hybridization, pathological, and molecular findings. Confirmation of the presence of PCV3 may increase co-infection with other causative agents of disease in Korean pig herds, indicating the need for further systemic investigation of pathogenicity and of multiple infections with PCV2 genotypes and bacteria, and the development of an effective PCV3 vaccine.
Aborted Fetus ; Agriculture ; Bacteria ; Circovirus ; Coinfection ; Dermatitis ; Genotype ; In Situ Hybridization ; Inflammation ; Korea ; Swine ; Virulence

A novel protein encoded by the open reading frame 4 (ORF4) was recently discovered in porcine circovirus type 2 (PCV2). However, little is known about the interaction proteins of ORF4 which hindered better understanding the biological functions of ORF4 in the life cycle of PCV2. In the present study, the ORF4 was inserted into the multiple cloning site of pCMV-N-Flag-GST, yielding recombinant plasmid pCMV-N-Flag-GST-ORF4. The recombinant plasmid was transfected into 293T cells and the intracellular interaction complex of ORF4 were enriched and separated by GST pull-down and SDS-PAGE, sequentially. The potential interacting proteins of PCV2 ORF4 were stained with silver and identified by mass spectrometry (MS). Finally, five candidate ORF4-interacting proteins, including Serine/threonine-protein phosphatase 6 catalytic subunit, alpha cardiac muscle 1, actin, SEC14-like protein 5 and myosin 9 were identified. These results would benefit a better understanding of the biological function of ORF4 in PCV2 infected cells.
Animals ; Circoviridae Infections ; Circovirus ; HEK293 Cells ; Humans ; Mass Spectrometry ; Open Reading Frames ; Swine ; Viral Proteins

The antigen gene expression level of a DNA vaccine is the key factor influencing the efficacy of the DNA vaccine. Accordingly, one of the ways to improve the antigen gene expression level of a DNA vaccine is to utilize a plasmid vector that is replicable in eukaryotic cells. A replicative DNA vaccine vector pCMVori was constructed based on the non-replicative pcDNA3.1 and the replicon of porcine circovirus 2 (PCV2) in this study. An EGFP gene was cloned into pCMVori and the control plasmid pcDNA3.1. The two recombinant vectors were transfected into PK-15 cell, and the plasmid DNA and RNA were extracted from the transfected cells. Real-time PCR was used to determine the plasmid replication efficiency of the two plasmids using plasmid before and after Bcl Ⅰ digestion as templates, and the transcription level of the Rep gene in PCV2 replicon was detected by RT-PCR. The average fluorescence intensity of cells transfected with the two plasmids was analyzed with software Image J, and the transcription level of EGFP was determined by means of real-time RT-PCR. The results showed that the replication efficiency of pCMVori in PK-15 cells incubated for 48 h was 136%, and the transcriptions of Rep and Rep' were verified by RT-PCR. The average fluorescence intensity of the cells transfected with pCMVori-EGFP was 39.14% higher than that of pcDNA3.1-EGFP, and the transcription level of EGFP in the former was also 40% higher than that in the latter. In conclusion, the DNA vaccine vector pCMVori constructed in this study can independently replicate in eukaryotic cells. As a result, the expression level of cloned target gene was elevated, providing a basis for developing the pCMVori-based DNA vaccine.
Animals ; Swine ; Circovirus/genetics* ; Vaccines, DNA/genetics* ; Replicon/genetics* ; Genetic Vectors/genetics* ; Plasmids/genetics*

Postweaning multisystemic wasting syndrome (PMWS), which was first identified in western Canada in 1991 and more recently in the United States, Europe and Asia, is an emerging disease in pigs. Porcine circovirus type 2 (PCV-2) is the primary infectious viral agent causing PMWS, but the full expression of the disease may require the presence of other agents. It is reported that there is apparent synergism between PCV-2 and porcine parvovirus (PPV) in increasing the severity of the clinical signs and lesions of PMWS. From January 2006 to May 2008, a total of the 154 lymph node samples were collected from 4~12 weeks old pigs which had been submitted to the College of Veterinary Medicine, Jeju National University, Korea. These pigs were diagnosed as PMWS on the basis of clinical and pathological examination from 48 commercial herds in Jeju Island. Based on the immunohistochemistry, porcine parvovirus was detected in 69 cases (44.8%) from 154 weaned or grower pigs. PPV antigens were detected in the cytoplasm of histiocytic cells multifocally infiltrated in the cortex and paracortex of lymph nodes. The results of this study clarify that PPV is prevalent in pigs with PMWS on Jeju Island. Therefore PPV is one of the most important co-agents in the development of naturally acquired PMWS. This study may be helpful to the control of this disease and to epidemiological aspects.
Asia ; Canada ; Circovirus ; Coinfection ; Cytoplasm ; Europe ; Immunohistochemistry ; Korea ; Lymph Nodes ; Parvovirus, Porcine ; Prevalence ; Swine ; United States ; Veterinary Medicine ; Wasting Syndrome

Salmonella (S.) Typhimurium is highly contagious, and its infection may rapidly spread within pig populations of herd. According to the survey (1,191 pigs) from 2003 to 2012, 155 pigs (13.0%) were diagnosed as salmonellosis in Jeju. Major porcine salmonellosis cases (88.4%) were concentrated in 4- to 12-week-old weaned pigs, but 6 pigs (3.9%) under 4 weeks old were also diagnosed. Based on the histopathologic examinations, ulcerative enteritis (63.9%) in the large intestine and/or paratyphoid nodules formation (57.4%) in the liver were most prevalent lesions in porcine salmonellosis. Single infection of S. Typhimurium and mixed infection with more than 2 pathogens were detected in 38 (24.5%) and 117 (75.5%) in pigs, respectively. Co-infections of Porcine reproductive and respiratory syndrome virus and Porcine circovirus type 2 were very common in porcine salmonellosis in Jeju and detected in 84 (54.2%) and 59 (38.1%) pigs, respectively. Based on the serotyping tests using 41 bacterial isolates, S. Typhimurium and S. Rissen were confirmed in 39 (95.1%) and 2 (4.9%) cases, respectively.
Circovirus ; Coinfection ; Enteritis ; Intestine, Large ; Liver ; Porcine respiratory and reproductive syndrome virus ; Prevalence* ; Salmonella ; Salmonella Infections* ; Salmonella typhimurium ; Serotyping ; Swine ; Ulcer

Porcine circovirus (PCV) is a small, nonenveloped virus that contains a single-stranded circular DNA genome of about 1.76 Kb and belongs to the family Circoviridae. The PCV-2 was thought to be one of the causative agents for postweaning multisystemic wasting syndrome (PMWS) in pigs. In this study, the complete genome of two PCV-2 Korean isolates (KSY-1 and KSY-2) were sequenced and characterized. Also, the ORF2 gene of KSY-1 isolate was expressed in baculovirus expression system and the expressed protein was characterized. The sequence data indicated that the PCV-2 genome of two Korean isolates were 1,768 bases in length and encoded 2 major proteins, Rep (ORF1, 314 amino acids, 37 kDa) and a capsid (ORF2, 233 amino acids, 28~30 kDa) protein. There were 5 glycosylation sites and stem-loop structures with the nonanucleotide (5-AAGTATTAC-3), typically seen in PCV-2. Compared to nucleotide sequences of PCV-1 and PCV-2 reference strains, two Korean isolates were closely related; that is, they showed 98% homology in nucleotide sequence each other. Also, they showed 95~99% homology in nucleotide sequences with those of PCV-2 isolates but 76% similarity with those of PCV-1 reference strains. A phylogenetic analysis revealed that nucleotide sequences of Korean isolates were close to those of PCV-2 (AF055392) isolated in Canada. The baculovirusexpressed ORF2 migrated at 30 kDa and reacted with PCV-2 specific antiserum by indiect fluorescent antibody and Western blot analyses. It is concluded that our results could be valuable to understand the molecular characteristics of PCV-2 and to develop diagnostic methods for PCV-2 infections.
Amino Acids ; Baculoviridae ; Base Sequence ; Blotting, Western ; Canada ; Capsid ; Circoviridae ; Circovirus* ; DNA, Circular ; Genome ; Glycosylation ; Humans ; Korea* ; Swine ; Wasting Syndrome