Isolation in cell cultures and initial characterisation of two novel bocavirus species from swine in Northern Ireland.

We report the isolation in cell cultures of two novel bocavirus species in pigs from farms in Northern Ireland with clinical postweaning multisystemic wasting syndrome (PMWS). We have designated the isolates as porcine bocavirus-3 (PBoV3) and porcine bocavirus-4 (PBoV4). To date 5082 and 4125 bps of PBoV3 and PBoV4 have been sequenced, respectively.

Sensitive detection of African swine fever virus using real-time PCR with a 5' conjugated minor groove binder probe.

The design of a 5' conjugated minor groove binder (MGB) probe real-time PCR assay is described for the rapid, sensitive and specific detection of African swine fever virus (ASFV) DNA. The assay is designed against the 9GL region and is capable of detecting 20 copies of a DNA standard. It does not detect any of the other common swine DNA viruses tested in this study.

Phylogenetic analysis of porcine circovirus type 2 (PCV2) pre- and post-epizootic postweaning multisystemic wasting syndrome (PMWS).

The porcine circovirus type 2 (PCV2) genome encodes three major open reading frames (ORFs) encoding the replicase proteins (ORF1), the viral capsid protein (ORF2), and a protein with suggested apoptotic activity (ORF3). Previous phylogenetic analyses of complete genome sequences of PCV2 from GenBank have demonstrated 95-100% intra-group nucleotide sequence identity. However, although these isolates were readily grouped into clusters and clades, there was no correlation between the occurrence of specific PCV2 genotypes and the geographic origin or health status of the pig.

Lack of in vitro and in vivo effects of lipopolysaccharide on porcine circovirus type 2 infection.

Porcine circovirus type 2 (PCV2) is the causative agent of postweaning multisystemic wasting syndrome (PMWS). The presence of immunostimulating factors or concurrent infections seems to be crucial for PMWS development. Lipopolysaccharide (LPS) is a potent immunological activator and has recently been suggested to enhance PCV2 replication in vitro.

Temporal distribution of porcine circovirus 2 genogroups recovered from postweaning multisystemic wasting syndrome affected and nonaffected farms in Ireland and Northern Ireland.

Porcine circovirus type 2 (PCV2) is now recognized as the essential infectious component of porcine postweaning multisystemic wasting syndrome (PMWS). PMWS was first recognized in high-status, specific pathogen-free pigs in Canada in 1991 and is now an economically important disease that affects the swine industry around the world. Recently, reports of genomic studies on PCV2 viruses indicated that 2 distinctive genogroups of PCV2 exist.

T lymphocyte epitope mapping of porcine circovirus type 2.

Immunoreactive T lymphocyte epitopes within the ORF1, ORF2, and ORF 3 products of porcine circovirus type 2 (PCV2) were mapped. For this, overlapping linear 20-mer peptides were synthesized and tested for their ability to induce T lymphocyte proliferation in porcine peripheral blood mononuclear cells (PBMCs) isolated from experimentally PCV2-infected pigs. After a preliminary screening of 31 (ORF1), 23 (ORF2), and 10 (ORF3) peptides using PBMCs from 4 PCV2-infected pigs, none of the peptides appeared to be immunoreactive (stimulation index [SI] : 2) in all four pigs.

Mycoplasma hyopneumoniae bacterins and porcine circovirus type 2 (PCV2) infection: induction of postweaning multisystemic wasting syndrome (PMWS) in the gnotobiotic swine model of PCV2-associated disease.

Groups (5 to 15 per group) of gnotobiotic swine were infected oronasally with porcine circovirus type 2 (PCV2) at 3 days of age and then given 1 of 6 different commercial Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins as either a single dose (7 d of age, 1 application products) or 2 doses (7 and 21 d of age, 2 application product). Control groups received PCV2 alone (n = 9) or were infected with PCV2 and immunized twice with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund's adjuvant (ICFA) (n = 7).

Structure-dependent modulation of alpha interferon production by porcine circovirus 2 oligodeoxyribonucleotide and CpG DNAs in porcine peripheral blood mononuclear cells.

DNA sequences containing CpG motifs are recognized as immunomodulators in several species. Phosphodiester oligodeoxyribonucleotides (ODNs) representing sequences from the genome of porcine circovirus type 2 (PCV2) have been identified as potent inducers (ODN PCV2/5) or inhibitors (ODN PCV2/1) of alpha interferon (IFN-alpha) production by porcine peripheral blood mononuclear cells (poPBMCs) in vitro. In this study, the IFN-alpha-inducing or -inhibitory activities of specific phosphodiester ODNs were demonstrated to be dependent on their ability to form secondary structures.

Molecular beacon real-time PCR detection of swine viruses.

Rapid and reliable detection of viral pathogens is critical for the management of the diseases threatening the economic competitiveness of the swine farming industry worldwide. Molecular beacon assays are one type of real-time polymerase chain reaction (PCR) technology capable of fast, specific, sensitive, and reliable viral detection. In this paper, the development of molecular beacon assays as novel tools for the rapid detection of Aujeszky's disease virus, African swine fever virus, porcine circovirus type 2 and porcine parvovirus is described.

Cytokine and C-reactive protein profiles induced by porcine circovirus type 2 experimental infection in 3-week-old piglets.

The purpose of this study was to determine serum profiles of cytokines at a protein level and Creactive protein (CRP) during the development of postweaning multisystemic wasting syndrome (PMWS) in experimentally inoculated pigs. Levels of serum IFN-alpha, IL-6, IL-10, and CRP were examined for a 35-day period in 10 piglets experimentally infected with PCV2 at 3 weeks of age. Four of the infected piglets developed severe PMWS at 14 to 21 days post-infection (d.

Infection of pigs in Ireland with lymphotropic gamma-herpesviruses and relationship to postweaning multisystemic wasting syndrome.

Three species of porcine lymphotropic herpesviruses (PLHVs) have been described but there are few reports on the distribution and prevalence of these viruses in domestic pigs. We aimed to determine the PLHV status of Irish commercial pig herds, and to this end spleens taken from 110 healthy adult pigs sourced from 22 geographically distributed farms in Ireland were analysed for PLHV DNA using novel species-specific polymerase chain reaction assays. We now report that PLHV infection is widespread in the Irish domestic pig population and that PLHV-1 infections are most common (74% of all animals tested), followed by PLHV-3 and PLHV-2 (45% and 21%, respectively) and that infections with multiple PLHV species were frequently detected.

Features of porcine circovirus-2 disease: correlations between lesions, amount and distribution of virus, and clinical outcome.

Tissue sets from 36 snatch-farrowed colostrum-deprived (SF/CD) and 71 Caesarian-derived gnotobiotic swine infected with porcine circovirus type 2 (PCV-2) as neonates were examined and scored for the types and tissue distribution of histologic lesions associated with this viral infection. The occurrence and severity of these lesions were correlated with qualitative and quantitative determinations of viral burden in tissues by immunohistochemistry (IHC) and tissue titrations for infectious virus, respectively. These measures were, in turn, related to 1 of 3 categories of clinical disease expressed in PCV-2-infected swine as subclinical infection, preclinical postweaning multisystemic wasting syndrome (PMWS), and clinically evident PMWS, respectively.

Subset-dependent modulation of dendritic cell activity by circovirus type 2.

Viral interactions with dendritic cells (DCs) have important consequences for immune defence function. Certain single-stranded DNA viruses that associate with a number of species, including humans and pigs, exhibit interesting characteristics in this context. Porcine circovirus type 2 (PCV2) can persist within myeloid DCs in the absence of virus replication.

Adaptation of an Invader assay for the detection of African swine fever virus DNA.

A closed tube isothermal Invader assay (Third Wave Technologies Inc., Madison, Wisconsin, USA) was adapted for the detection of African swine fever virus (ASFV) DNA. Several ASFV Invader assays were designed successfully and tested on a real-time PCR instrument (iCycler, BioRad).

Interlaboratory testing of porcine sera for antibodies to porcine circovirus type 2.

A panel of 20 porcine sera was distributed to 5 laboratories across Europe and Canada. Each center was requested to test the sera for the presence of porcine circovirus type 2 antibodies using the routine assays, indirect immunofluorescence assay (IFA) and indirect immunoperoxidase monolayer assay (IPMA), and to determine the titer of each serum. Results from all centers were then compiled and correlated.

Reproduction of postweaning multisystemic wasting syndrome in pigs experimentally inoculated with a Swedish porcine circovirus 2 isolate.

In recent years, porcine circovirus type 2 (PCV2)-associated postweaning multisystemic wasting syndrome (PMWS) has been reported worldwide. However, to date, PMWS has not been reported in Sweden despite the demonstration of serum antibodies to a PCV2-like virus in Swedish pigs. This communication reports the experimental reproduction of clinical PMWS after inoculation of colostrum-deprived (CD) pigs, derived from a Northern Ireland herd, with an isolate of PCV2 virus recovered from a clinically normal Swedish pig that was necropsied in 1993.

Identification of a sequence from the genome of porcine circovirus type 2 with an inhibitory effect on IFN-alpha production by porcine PBMCs.

Porcine circovirus type 2 (PCV-2) has been identified as the causal agent of postweaning multisystemic wasting syndrome and has been associated with several other disease syndromes in pigs. To date, however, little is known regarding the mechanism(s) underlying the pathogenesis of PCV-2-induced diseases and the interaction of the virus with the host immune system. In the present study, oligodeoxynucleotides (ODNs), with central CpG motifs selected from the genome of PCV-2, were demonstrated to modulate the immune response of porcine PBMCs.

Porcine circovirus 2-associated disease in Eurasian wild boar.

Porcine circovirus 2 (PCV2) was first identified in high-health herds of domestic swine and was associated with a debilitating disease called postweaning multisystemic wasting syndrome (PMWS). Most subsequent studies have indicated that PCV2 infects only swine but there is little information on porcids other than improved breeds of domestic swine. Multisystemic disease was reported in a group of Eurasian wild boars raised under free-range conditions.

Absence of evidence of porcine circovirus infection in piglets with congenital tremors.

Porcine circovirus types 1 (PCV1) and 2 (PCV2) have been associated with congenital tremors (CTs) in piglets in the United States. In this study, central nervous system and nonneural tissues of 40 CT piglets from Spain, the United Kingdom, Ireland, and Sweden were investigated for the presence of PCV1 and PCV2 using in situ hybridization and immunohistochemical labeling on paraffin sections. The polymerase chain reaction for PCV2 was also carried out on sera from the Spanish CT cases.

Immunologic features of porcine circovirus type 2 infection.

Clinical expression of porcine circovirus 2 (PCV-2) infection in swine may result in two distinct high mortality disease syndromes. In North America, postweaning multisystemic wasting syndrome (PMWS), while still sporadic in incidence, predominates. In Europe and elsewhere, both PMWS and a second syndrome, porcine dermatitis and nephropathy syndrome (PDNS), occur in endemic and epidemic forms.

Exudative epidermitis and porcine circovirus-2 infection in a Swedish SPF-herd.

An outbreak of exudative epidermitis (EE) among piglets in a Swedish SPF-herd initiated a survey for indications as to the cause of disease. The herd was established by caesarean section and has been closed to all new animal material, with the exception of semen for artificial insemination (AI). The study comprised serum samples from the SPF-herd over a 10-year period (n=109) and a close monitoring of animals in the herd during the period after the EE outbreak.