| pcr detection of porcine circovirus type 2 dna in whole blood, serum, oropharyngeal swab, nasal swab, and feces from experimentally infected pigs and field cases. | porcine circovirus type 2 (pcv2) shedding patterns were investigated by polymerase chain reaction (pcr) for the detection of pcv2 dna, and the diagnostic suitability of a sample for the pcr was examined by using different types of samples. in the experimental infection, sixteen pigs were inoculated intranasally with pcv2. the samples, including oropharyngeal and nasal swabs, feces, whole blood and serum became positive for pcv2 dna by pcr immediately after the inoculation, and almost all samples ... | 2003 | 12679576 |
| optimal enhancement of in situ hybridization for the detection of porcine circovirus 2 in formalin-fixed, paraffin-wax-embedded tissues using a combined pretreatment of thermocycler and proteinase k. | optimal enhancement of the hybridization signal was developed for the detection of porcine circovirus (pcv) 2 in formalin-fixed, paraffin-wax-embedded tissues from pigs with postweaning multisystemic wasting syndrome. the hybridization signal obtained after thermocycler pretreatment was very uniform across the section, whereas the signal obtained after either proteinase k or microwave pretreatment not only was weaker but was of variable intensity across sections. thermocycler pretreatment combin ... | 2003 | 12726742 |
| association of lymphopenia with porcine circovirus type 2 induced postweaning multisystemic wasting syndrome (pmws). | the composition of peripheral blood leukocyte populations was studied following experimental pcv2-infection in 3-week-old piglets. four of 10 pcv2-infected piglets developed clinical and pathological symptoms consistent with postweaning multisystemic wasting syndrome (pmws) between 14 and 21 days post-inoculation (p.i.), and were characterised as pmws-affected. only these four pmws-affected piglets, but neither the non-symptomatic infected nor control animals, developed a clear leukopenia. kinet ... | 2003 | 12730011 |
| isolation and characterization of porcine circovirus type-2 from sera of stillborn fetuses. | in order to examine an association between porcine circovirus type-2 (pcv2) infection and reproductive failure in pigs, sera (n = 171) from stillborn fetuses were collected from 3 different farms with prolonged histories of reproductive problems. these sera were tested for the presence of antibodies to pcv2 using an immunoperoxidase monolayer assay. of the 171 sera tested, 28 had pcv2 antibody titers of > or = 1:16. when these 28 samples were tested by a polymerase chain reaction assay,13 were f ... | 2003 | 12760475 |
| comparative serologic and virologic study of commercial swine herds with and without postweaning multisystemic wasting syndrome. | a comparative serologic and virologic study was performed in pigs from 5 herds with postweaning multisystemic wasting syndrome (pmws) and 2 herds without pmws in quebec. in each herd, 60 blood samples were collected at 4-wk intervals from pigs from 3 to 23 wk of age. the serum was evaluated for the presence of antibodies to porcine circovirus type 2 (pcv2) and porcine reproductive and respiratory syndrome virus (prrsv), as well as for the presence of nucleic acid of pcv2, prrsv, an porcine parvo ... | 2003 | 12760476 |
| multiplex nested pcr compared with in situ hybridization for the differentiation of porcine circoviruses and porcine parvovirus from pigs with postweaning multisystemic wasting syndrome. | multiplex nested polymerase chain reactions (pcrs) were developed for the simultaneous detection and differentiation of genomic material of porcine circovirus 1 (pcv1), porcine circovirus 2 (pcv2), and porcine parvovirus (ppv) in formalin-fixed, paraffin-embedded tissues. multiplex conventional and nested pcr and in situ hybridization were compared for their ability to detect the 3 viruses in such tissues. xylene deparaffinization followed by proteinase k digestion yielded dna of sufficient qual ... | 2003 | 12760479 |
| comparative analysis of the transcriptional patterns of pathogenic and nonpathogenic porcine circoviruses. | the rnas of porcine circovirus type 1 (pcv1) synthesized in pk15 cells were characterized. a total of 12 rnas were detected. they include the viral capsid protein rna (cr), a cluster of eight rep-associated rnas (designated rep, rep', rep3a, rep3b, rep3c-1, rep3c-2, rep3c-3, and rep3c-4), and three ns-associated rnas (designated ns462, ns642, and ns0). members of the rep-associated rna cluster all share common 5'- and 3'-nucleotide sequences and they share common 3'-nucleotide sequence with the ... | 2003 | 12788629 |
| an orf2 protein-based elisa for porcine circovirus type 2 antibodies in post-weaning multisystemic wasting syndrome. | porcine circovirus type 2 (pcv2) plays a crucial role in the pathogenesis of post-weaning multisystemic wasting syndrome (pmws) in swine. as pcv2 displays significant homology with pcv1 (a non-pathogenic virus) at the nucleotide and amino-acid level, a discriminative antigen is needed for specific serological diagnosis. the orf2-encoded capsid protein from pcv2 was used to develop an indirect enzyme-linked immunosorbent assay (elisa). gst-fused capsid protein from pcv2 and gst alone (both expres ... | 2003 | 12814886 |
| immunohistochemical characterisation of pcv2 associate lesions in lymphoid and non-lymphoid tissues of pigs with natural postweaning multisystemic wasting syndrome (pmws). | the lymphoid, renal, pulmonary, and hepatic lesions of naturally occurring postweaning multisystemic wasting syndrome (pmws) affected pigs have been studied by means of immunohistology. ten conventionally reared pigs showing acute clinical signs of pmws were selected from a farm on which animal were seronegative to porcine reproductive and respiratory virus and to aujeszky's disease virus. all pigs were positive in tests for porcine circovirus type 2 by ish and ihc. monoclonal and polyclonal ant ... | 2003 | 12842612 |
| change of porcine circovirus 2 target cells in pigs during development from fetal to early postnatal life. | change of porcine circovirus 2 (pcv2) target cells during development from fetal to postnatal life in pigs was examined. pcv2 inoculation was performed in fetuses in utero at either 57, 75 or 92 gestational days and in piglets at 1 day of age. twenty-one days after virus inoculation, pcv2-infected cells in the heart, lungs, liver, spleen and inguinal lymph nodes were localized and immuno-phenotyped by double-immunofluorescence labeling using different cell markers and pcv2-antibodies. during fet ... | 2003 | 12860073 |
| coinfection by cryptosporidium parvum and porcine circovirus type 2 in weaned pigs. | routine histopathological diagnosis of one representative 3-month-old pig from a group suffering from diarrhoea revealed a massive degree of parasitation by cryptosporidium parvum, with a concomitant infection by porcine circovirus type 2 (pcv2), that was confirmed by immunohistochemical procedures. the areas of intestine where parasites were more numerous presented abundant pcv2 infected cells in mucosa and submucosa. the concurrence of c. parvum, a rare primary intestinal pathogen in post-wean ... | 2003 | 12864903 |
| cytokine mrna expression profiles in lymphoid tissues of pigs naturally affected by postweaning multisystemic wasting syndrome. | fifteen 8-week-old conventional pigs were selected from a farm where pigs were suffering from postweaning multisystemic wasting syndrome (pmws). ten of the animals were diseased pigs showing typical signs of pmws (wasting and respiratory disorders) and positive for infection with porcine circovirus type 2 (pcv2), and the other five animals selected as controls were pen-mate, apparently healthy pigs. blood samples and lymphoid tissues were taken from each animal for haematological, serological an ... | 2003 | 12867643 |
| simultaneous detection and differentiation between porcine circovirus and porcine parvovirus in boar semen by multiplex seminested polymerase chain reaction. | a multiplex seminested polymerase chain reaction (pcr) was developed for the simultaneous detection and differentiation among porcine circovirus 1 (pcv1), pcv2, and porcine parvovirus (ppv) from boar semen. primers of pcv1, pcv2 and ppv were specific and did not react with other viruses respectively. twenty (20.4%) and 42 (42.9%) out of 98 whole semen samples were found to be positive for pcv and ppv using multiplex conventional and seminested pcr, respectively. when the separated fractions of p ... | 2003 | 12867738 |
| pcv2 replicase transcripts in infected porcine kidney (pk15) cells. | the circoviridae family includes small viruses containing circular single strand dna. there are two circoviruses described in pigs. porcine circovirus 2 (pcv2) has been linked to a disease termed postweaning multisystemic wasting syndrome (pmws) whereas a close relative of this virus, termed pcv type 1 (pcv1) has been considered a non-pathogenic contaminant of the pk15 cell line. rolling circle replication of small dna viruses like circoviruses is mediated by a replicase (rep) gene that is trans ... | 2002 | 12881643 |
| three-dimensional structure of penicillium chrysogenum virus: a double-stranded rna virus with a genuine t=1 capsid. | although double-stranded (ds) rna viruses are a rather diverse group, they share general architectural principles and numerous functional features. all dsrna viruses, from the mammalian reoviruses to the bacteriophage phi6, including fungal viruses, share a specialized capsid involved in transcription and replication of the dsrna genome, and release of the viral plus strand rna. this ubiquitous capsid consists of 120 protein subunits in a so-called t=2 organization. the stringent requirements of ... | 2003 | 12888349 |
| in vitro studies on the infection and replication of porcine circovirus type 2 in cells of the porcine immune system. | porcine circovirus type 2 (pcv2) nucleic acid and/or antigens are consistently observed in cells of monocytic morphology in lesions of pigs affected by post-weaning multisystemic wasting syndrome (pmws). in this study, pcv2 antigen was detected in the cytoplasm of monocytes, pulmonary macrophages (pms) and monocyte-derived macrophages exposed to the virus in vitro, by immunofluorescence analysis (ifa) and the phenotype of these cells confirmed by detection of monocytic cell surface markers using ... | 2003 | 12909411 |
| mapping of viral rna sequences required for assembly of peanut clump virus particles. | rna sequences required for assembly into rod-shaped virions of rna-1 and rna-2 of peanut clump virus (pcv) were mapped by testing the ability of different rna-1 and -2 deletion mutants to be encapsidated in vivo in an rnase-resistant form. encapsidation of rna-1 was found to require a sequence domain in the 5'-proximal part of the p15 gene, the 3'-proximal gene of rna-1. on the other hand, the subgenomic rna which encodes p15 was not encapsidated, suggesting that other features of rna-1 are impo ... | 2003 | 12917480 |
| 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. affected young pigs had pneumonia and enterit ... | 2003 | 12918819 |
| detection of porcine circovirus type 2 in feces of pigs with or without enteric disease by polymerase chain reaction. | to establish the sensitive polymerase chain reaction(pcr) method and detect porcine circovirus type 2 (pcv2) from intestines and feces of commercial swine herds with or without enteric disease, intestinal samples from 68 pigs and 29 fecal samples from commercial swine farms were collected. a primer set, forward primer 5'-gaagaatggaagaagcgg-3' and reverse primer 5'-ctcacagcagtagacaggt-3', could detect the virus at a concentration as low as 2 infectious virions per milliliter under controlled cond ... | 2003 | 12918820 |
| exogenous porcine viruses. | porcine organs, cells and tissues provide a viable source of transplants in humans, though there is some concern of public health risk from adaptation of swine infectious agents in humans. limited information is available on the public health risk of many exogenous swine viruses, and reliable and rapid diagnostic tests are available for only a few of these. the ability of several porcine viruses to cause transplacental fetal infection (parvoviruses, circoviruses, and arteriviruses), emergence or ... | 2003 | 12934944 |
| new reporter gene-based replication assay reveals exchangeability of replication factors of porcine circovirus types 1 and 2. | two types of porcine circovirus (pcv), which differ in their pathogenicity, are known. pcv type 2 (pcv2) is the etiological agent of postweaning multisystemic wasting syndrome in swine, while pcv1 has not yet been linked to a disease. corroborating earlier observations in pcv1, transcript mapping revealed that the rep gene of pcv2 encodes two products, the full-length protein rep and the spliced version rep' and that the simultaneous expression of rep and rep' proteins is essential for initiatio ... | 2003 | 12941898 |
| effect of vaccination with selective bacterins on conventional pigs infected with type 2 porcine circovirus. | the objective of this study was to determine whether vaccination with bacterins commonly used in the usa, when administered at a time typical of us protocol, enhances porcine circovirus type 2 (pcv2) replication and the incidence and severity of clinical signs and lesions characteristic of postweaning multisystemic wasting syndrome (pmws) in conventional pigs. sixty-one pigs free of pcv2 were randomly assigned to four groups. groups 1 (n = 15) and 2 (n = 15) pigs served as sham-inoculated negati ... | 2003 | 12949409 |
| the essential and nonessential transcription units for viral protein synthesis and dna replication of porcine circovirus type 2. | during porcine circovirus (pcv) replication in pk15 cells, nine pcv type 2 (pcv2)-specific rnas are synthesized. they include the capsid rna (cr), five rep-associated rnas (rep, rep', rep3a, rep3b, and rep3c), and three ns-associated rnas (ns515, ns672, and ns0). in this work, mutational analyses were conducted to investigate the involvement of each pcv2 transcription unit in viral protein synthesis and dna replication. the results demonstrated that a stop codon introduced at the very 5'-end of ... | 2003 | 12954212 |
| development of a polyclonal-antibody-based immunohistochemical method for the detection of type 2 porcine circovirus in formalin-fixed, paraffin-embedded tissue. | an immunohistochemical method for the detection of type 2 porcine circovirus (pcv2) in paraffin-embedded tissue was developed. rabbits were inoculated with purified pcv2 to obtain a polyclonal antiserum. antiserum was applied to sections of porcine tissue that contained lesions consistent with postweaning multisystemic wasting syndrome and in which pcv2 genome had been demonstrated by in situ hybridization. in all cases (18/18), the density and distribution of positive cells detected by in situ ... | 1999 | 12968735 |
| myocarditis and abortion associated with intrauterine infection of sows with porcine circovirus 2. | porcine circovirus 2 (pcv2) is a recently identified agent that has been associated with postweaning multisystemic wasting syndrome (pmws) in swine populations. in this report, the potential spectrum of disease associated with pcv2 is expanded by evidence of vertical transmission and associated reproductive failure. pcv2 was isolated from a litter of aborted piglets from a farm experiencing late-term abortions and stillbirths. severe, diffuse myocarditis was present in 1 piglet associated with e ... | 1999 | 12968736 |
| immunogenicity and pathogenicity of chimeric infectious dna clones of pathogenic porcine circovirus type 2 (pcv2) and nonpathogenic pcv1 in weanling pigs. | porcine circovirus type 2 (pcv2) is the primary causative agent of postweaning multisystemic wasting syndrome (pmws), whereas the ubiquitous porcine circovirus type 1 (pcv1) is nonpathogenic for pigs. we report here the construction and characterization of two chimeric infectious dna clones of pcv1 and pcv2. the chimeric pcv1-2 clone contains the pcv2 capsid gene cloned in the backbone of the nonpathogenic pcv1 genome. a reciprocal chimeric pcv2-1 dna clone was also constructed by replacing the ... | 2003 | 14512571 |
| conjugated linoleic acid ameliorates viral infectivity in a pig model of virally induced immunosuppression. | we investigated the cellular and molecular immunoregulatory actions of conjugated linoleic acid (cla) of relevance to viral disease pathogenesis and antiviral responses. to test the hypothesis that cla ameliorates viral disease, we developed a viral challenge model by infecting pigs with type-2 porcine circovirus (pcv2). after 42 d of dietary supplementation with either soybean oil (n = 16) or cla (n = 16), half of the pigs in each group were challenged with pcv2. we examined the effect of cla o ... | 2003 | 14519812 |
| acute hepatitis in a piglet experimentally inoculated with tissue homogenates from pigs with postweaning multisystemic wasting syndrome. | five 2 day-old colostrum-deprived piglets were inoculated with tissue homogenates from pigs with postweaning multisystemic wasting syndrome. one of the five piglets developed icterus and died 23 days post-inoculation. histologic examination revealed acute hepatitis. porcine circovirus type 2 (pcv-2) antigen and nucleic acid were detected in hepatocytes and phagocytic cells. ultrastructurally, hepatocytes and phagocytic cells had large numbers of cytoplasmic inclusions, which were composed of ele ... | 2003 | 14532704 |
| association of porcine circovirus 2 with porcine respiratory disease complex. | a retrospective study was performed on natural cases of porcine respiratory disease complex (prdc) to determine the association and prevalence of prdc with porcine circovirus 2 (pcv2) and other co-existing pathogens in korea. histologically, alveolar septa were markedly thickened by infiltrates of mononuclear cells. moderate to marked multifocal peribronchial and peribronchiolar fibrosis were present and often extended into the airway lamina propria. among the 105 pigs with prdc, 85 were positiv ... | 2003 | 14550736 |
| effects of dexamethasone on the pathogenesis of porcine circovirus type 2 infection in piglets. | to investigate the effect of immunosuppression on porcine circovirus type 2 (pcv2) infection, hysterectomy-produced, colostrum-deprived piglets were inoculated with the virus by the intranasal or intraperitoneal route, with or without dexamethasone (dex) treatment. eleven piglets aged 8 days were divided into four groups, namely group a (four animals given pcv2), b (three given pcv2 with dex), c (two given sterile medium with dex) and d (two given sterile medium). no significant clinical signs w ... | 2003 | 14554127 |
| 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 m ... | 2003 | 14573798 |
| protection of swine against post-weaning multisystemic wasting syndrome (pmws) by porcine circovirus type 2 (pcv2) proteins. | porcine circovirus type 2 (pcv2) is known to be associated with post-weaning multisystemic wasting syndrome (pmws), a recently described disease of young pigs. since no pcv2 vaccine was available so far, we have developed a specific pcv2 vaccine candidate. the orf1-encoded replication protein and orf2-encoded capsid protein of pcv2 were expressed and detected in either mammalian or insect expression systems. in a first trial, orf2 protein was found to be a major immunogen, inducing protection in ... | 2003 | 14575769 |
| characterization of the recombinant proteins of porcine circovirus type2 field isolate expressed in the baculovirus system. | porcine circovirus (pcv) type2 was isolated using primary porcine kidney cells from lymph node of piglets with typical pmws. the presence of the virus was identified by pcr using primers specific to pcv type2. the orfs 1 and 2 were amplified by pcr using primers corresponding to the target genes of the pcv type 2. cloned genes were inserted into the baculovirus expression vector and pcv recombinant proteins were expressed using baculovirus expression system. recombinant protein expression was de ... | 2002 | 14614268 |
| genetic characterization of porcine circovirus-2 field isolates from pmws pigs. | pmws is a new emerging disease in swine herds worldwide. field isolates of pcv-2, a putative major causative agent of pmws, were isolated and genetically characterized. viral genome of two field isolates (pc201dj and pc201ss) from pigs showing typical pmws was sequenced. the nucleotide sequence homology with other pcv-2 isolates was ranging from 95% to 99% in complete viral genomic sequence. the highly conserved nonanucleotide motif of replication origin was identical to that of other pcv-2 isol ... | 2002 | 14614270 |
| concurrent presence of porcine circovirus type 2 and porcine parvovirus in retrospective cases of exudative epidermitis in pigs. | | 2004 | 14623159 |
| susceptibility of pig embryos to porcine circovirus type 2 infection. | the aim of the present study was to determine if porcine circovirus type 2 (pcv2) is able to infect embryonic cells of in vivo produced porcine embryos with and without zona pellucida (zp). zp-intact and zp-free morulae (6-day post-insemination) and early blastocysts (7-day post-insemination), and hatched blastocysts (8-day post-insemination) were exposed to 10(5.0) tcid50 pcv2 per ml (strain 1121, fifth passage pk15). at 48 h post-incubation, the percentage of infected embryos and the percentag ... | 2004 | 14643864 |
| comparison of the structures of three circoviruses: chicken anemia virus, porcine circovirus type 2, and beak and feather disease virus. | circoviruses are small, nonenveloped icosahedral animal viruses characterized by circular single-stranded dna genomes. their genomes are the smallest possessed by animal viruses. infections with circoviruses, which can lead to economically important diseases, frequently result in virus-induced damage to lymphoid tissue and immunosuppression. within the family circoviridae, different genera are distinguished by differences in genomic organization. thus, chicken anemia virus is in the genus gyrovi ... | 2003 | 14645560 |
| dendritic cells harbor infectious porcine circovirus type 2 in the absence of apparent cell modulation or replication of the virus. | dendritic cells (dcs) play crucial roles in innate and adaptive immune responses, rendering them critical targets for virus infections. porcine circovirus type 2 (pcv2) is associated with the development of postweaning multisystemic wasting syndrome (pmws) in piglets. we demonstrate here that 80 to 90% of monocyte-derived and bone marrow-derived dcs interact with pcv2 similar to the early stages of an infection. there was no evidence for virus replication, but the virus did persist in dcs withou ... | 2003 | 14645585 |
| cytokine profiles of peripheral blood mononuclear cells from pigs with postweaning multisystemic wasting syndrome in response to mitogen, superantigen or recall viral antigens. | in vitro cytokine profiles of peripheral blood mononuclear cells (pbmc) from pigs with postweaning multisystemic wasting syndrome (pmws) and healthy pigs were determined in response to recall viral antigens (porcine circovirus type 2; pcv2), mitogens (phytohaemagglutinin) or superantigens (staphylococcal enterotoxin b). pbmc from pmws-affected pigs, in contrast to those from healthy pigs, responded to recall pcv2 antigen by releasing il-10 and ifn-gamma, but they were less able or even unable to ... | 2003 | 14645926 |
| [case report: porcine circovirus type 2 infection in an european wild boar (sus scrofa) in the state of brandenburg, germany]. | this case represents the first case of porcine circovirus type 2 (pcv-2)--infection in a free living european wild boar associated with morphological lesions, which are regarded as characteristic for postweaning multisystemic wasting syndrome (pmws) in domestic pigs. the animal, an approximately 10 month old male, was found dead in a rural area within the state of brandenburg, germany. the closest commercial pig farm is located in 3 km distance from the spot where the carcass was found. at necro ... | 2003 | 14650740 |
| 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 ... | 2003 | 14667018 |
| characterisation of hungarian porcine circovirus 2 genomes associated with pmws and pdns cases. | the authors report the data of the first survey on the incidence of post-weaning multisystemic wasting syndrome (pmws) and porcine dermatitis and nephropathy syndrome (pdns) in hungary. a pcr method specific for the detection of porcine circovirus 2 (pcv-2) was developed, which proved to be suitable for diagnostic purposes. pcr screening of organ samples from pigs suspected to be affected with pmws or pdns revealed the presence of pcv-2 in 80% of the cases. six pcv-2 genomes from hungarian isola ... | 2003 | 14680067 |
| monitoring for potentially xenozoonotic viruses in new zealand pigs. | shortage of human donor organs for transplantation has prompted evaluation of animals as an alternative donor source. pigs are the most acceptable candidate animals but issues of xenozoonozes remain. despite careful monitoring of high-health-status (hhs) pigs, there is still a risk that their tissues may carry infectious agents. furthermore, pathogens which are significant in xenotransplantation are not necessarily those of veterinary importance. the detection of these potentially transmissible ... | 2004 | 14695679 |
| apoptosis and proliferative activity in lymph node reaction in postweaning multisystemic wasting syndrome (pmws). | postweaning multisystemic wasting syndrome (pmws) affects nursery and growing pigs, and is characterized by wasting, failure to thrive, pale skin, respiratory distress, diarrhoea and sometimes jaundice. macroscopic findings are aspecific, but lymphocyte depletion in lymphoid tissues is one of the histological hallmarks [vet. q. 24 (2002) 109]. spontaneous cases of pmws were studied to evaluate proliferative activity and apoptosis as mechanisms involved in the pathogenesis of cell depletion in ly ... | 2004 | 14700535 |
| use of a polymerase chain reaction assay and an elisa to monitor porcine circovirus type 2 infection in pigs from farms with and without postweaning multisystemic wasting syndrome. | to determine whether correlations exist between viremia with porcine circovirus type 2 (pcv2) and serum antibody profiles and between detection of pcv2 in nasal cavities and viremia of pigs from farms with and without postweaning multisystemic wasting syndrome (pmws). | 2004 | 14719708 |
| molecular biology of porcine circovirus: analyses of gene expression and viral replication. | the rep gene of porcine circovirus type 1 directs the synthesis of two proteins. the full-length protein rep is 312 amino acids in size, the spliced variant rep' is truncated (168 aa) and exon 2 is frame-shifted. replication of pcv1 dna depends on synthesis of both proteins. rep and rep' bind in vitro to double-stranded dna fragments comprising part of the origin of replication of pcv1, but the minimal binding sites of the two proteins are distinct. rep protein represses the promoter of the rep ... | 2004 | 14741119 |
| the clinical expression and emergence of porcine circovirus 2. | since its discovery and characterization in western canada in 1995, the distribution of post-weaning multisystemic wasting syndrome (pmws) has grown and the syndrome is undoubtedly recognized worldwide. more recently, there is a heightened interest in several potentially related conditions including porcine dermatitis and nephropathy syndrome (pdns), proliferative and necrotizing pneumonia (pnp), congenital tremors (ct-aii), perinatal myocarditis and reproductive failure. although the causality ... | 2004 | 14741125 |
| pathological findings associated with naturally acquired porcine circovirus type 2 associated disease. | porcine circovirus type 2 (pcv2) is a novel virus of the circoviridae family which is considered the cause of postweaning multisystemic wasting syndrome (pmws). pcv2 has also been associated to a number of pathological conditions of pigs, including porcine dermatitis and nephropathy syndrome, reproductive failure, porcine respiratory disease complex, proliferative and necrotising pneumonia and congenital tremor type aii. pathological studies have been used to describe and characterise pmws and t ... | 2004 | 14741126 |
| porcine circovirus-2 and concurrent infections in the field. | porcine circovirus-2 (pcv-2) is the necessary cause of post-weaning multisystemic wasting syndrome (pmws) in swine; however, a variety of co-factors, including other infectious agents, are thought to be necessary in the full expression of disease. porcine parvovirus (ppv) was found in the inoculum used in the first experiments to reproduce pmws in gnotobiotic swine. retrospective and prospective studies in the field and laboratory have demonstrated pcv-2 can act synergistically with ppv to enhan ... | 2004 | 14741128 |
| pmws: experimental model and co-infections. | porcine circovirus type 2 (pcv2) is now recognised as the causal agent of porcine multisystemic wasting syndrome (pmws), an economically important wasting disease of young pigs [j. vet. diagn. invest. 12 (2000) 3]. gross lesions of pmws include generalised lymphadenopathy, hepatitis, nephritis and pneumonia and typical histological lesions include lymphocytic depletion and multinucleated giant cell formation in lymph nodes, degeneration and necrosis of hepatocytes, and multifocal lymphohistocyti ... | 2004 | 14741129 |
| avian circovirus diseases: lessons for the study of pmws. | the diseases associated with psittacine beak and feather disease virus (bfdv), pigeon circovirus (picv) and goose circovirus (gocv), which can be classified with porcine circovirus type 2 (pcv2) as members of the genus circovirus of the family circoviridae, have clinico-pathological features in common with post-weaning multisystemic wasting syndrome (pmws), with which pcv2 infection is causally associated. intracytoplasmic botryoid inclusions within macrophages and depletion of t and b lymphocyt ... | 2004 | 14741130 |
| viremia and effect of fetal infection with porcine viruses with special reference to porcine circovirus 2 infection. | this publication reviews some pathogenetic features of the transplacental infection with porcine viruses in sows. viremia either with virus freely circulating or associated to peripheral blood mononuclear cells (pbmc) is an essential part of such pathogenesis. virus replication occurs either in fetal tissues only or both in fetal and maternal tissues and the outcome may be different. since porcine circovirus 2 (pcv2) has been associated with reproductive failure in sows, the question was asked w ... | 2004 | 14741131 |
| molecular characterization of porcine circovirus type 2 isolates from post-weaning multisystemic wasting syndrome-affected and non-affected pigs. | porcine circovirus type 2 (pcv2) is recognized as a primary cause in post-weaning multisystemic wasting syndrome (pmws). in this study, both pcv1 and pcv2 types were studied in pigs originating from pmws-affected (+) and non-affected (-) herds from brittany. pcv2 was identified by pcr in 100 % of animals from pmws(+) herds and in 76 % from pmws(-) herds, while pcv1 was not detected. the complete sequences of 38 pcv2 isolates were determined and 23 new variants were identified, displaying between ... | 2004 | 14769887 |
| a comparison of virus isolation, polymerase chain reaction, immunohistochemistry, and in situ hybridization for the detection of porcine circovirus 2 and porcine parvovirus in experimentally and naturally coinfected pigs. | virus isolation, polymerase chain reaction (pcr), immunohistochemistry, and in situ hybridization were compared for the detection of porcine circovirus 2 (pcv2) and porcine parvovirus (ppv) from experimentally and naturally coinfected pigs. all coinfected pigs developed postweaning multisystemic wasting syndrome (pmws), characterized by sudden onset of depression and anorexia. microscopically, granulomatous inflammation with intracytoplasmic inclusion bodies was present in lymph node from all co ... | 2004 | 14974846 |
| sequence requirements for the development of a chimeric hcv replicon system. | the hepatitis c virus (hcv) 3'nontranslated region (3'ntr) is important for virus infection and replicon replication. here, we constructed a panel of chimera replicons containing non-structural (ns) and 3'ntr sequences from different hcv strains or types, and examined the requirements for stable replication. a subgenomic replicon chimera comprising the polymerase and 3'ntr from hcv strain con1, and other non-structural genes from type 1a strain h77, supported stable colony formation and replicat ... | 2004 | 15019239 |
| comparison of porcine circovirus type 2 load in serum quantified by a real time pcr in postweaning multisystemic wasting syndrome and porcine dermatitis and nephropathy syndrome naturally affected pigs. | postweaning multisystemic wasting syndrome (pmws) diagnosis is based on the presence of characteristic histopathological lymphoid lesions and porcine circovirus type 2 (pcv2) within these lesions. previous studies indicate that pcv2 load is higher in pmws affected than in pcv2 infected, healthy pigs. on the other hand, pcv2 has been suggested to play a role in porcine dermatitis and nephropathy syndrome (pdns) pathogenesis. this study describes a new taqman real time pcr assay and its use to qua ... | 2004 | 15019262 |
| effect of porcine parvovirus vaccination on the development of pmws in segregated early weaned pigs coinfected with type 2 porcine circovirus and porcine parvovirus. | the objectives of this study were to determine if coinfection of segregated early weaned (sew) pigs with porcine circovirus type 2 (pcv2) and porcine parvovirus (ppv) induces an increase in the incidence of post-weaning multisystemic wasting syndrome (pmws) compared to singular pcv2 infection, and to determine if vaccination against ppv protects pigs against pmws associated with pcv2/ppv coinfection in sew pigs. seventy, 3-week-old, sew pigs were randomly assigned to one of the five groups. pigs ... | 2004 | 15036529 |
| a novel approach to intrauterine viral inoculation of swine using pcv type 2 as a model. | experimentally intrauterine (iu) viral inoculation has been commonly used to circumvent maternal interference with transplacental infection of fetuses and to assess the effect of viral infection on fetal development or reproductive parameters. however, iu inoculation requires surgical procedures such as laparatomy and surgical incision of the uterus. post-surgical complications, that frequently result in abortion or fetal death, have been a major disadvantage. an animal trial was conducted to ev ... | 2004 | 15036992 |
| detection of template strand switching during initiation and termination of dna replication of porcine circovirus. | nucleotide substitution mutagenesis was conducted to investigate the importance of the inverted repeats (palindrome) at the origin of dna replication (ori) of porcine circovirus type 1 (pcv1). viral genomes with engineered mutations on either arm or both arms of the palindrome were not impaired in protein synthesis and yielded infectious progeny viruses with restored or new palindromes. thus, a flanking palindrome at the ori was not essential for initiation of dna replication, but one was genera ... | 2004 | 15047840 |
| 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. they demonstrate a wide variation in the titers obtained between laboratories. these differ ... | 2004 | 15053371 |
| immunisation against pcv2 structural protein by dna vaccination of mice. | porcine circovirus type 2 (pcv2) is the causative agent of an emerging swine disease, postweaning multisystemic wasting syndrome (pmws). the disease affects primarily 5-12-weeks-old pigs which might suggest that infection with pcv2 occurs when the level of maternal antibodies have declined to sub-protective levels around weaning at 3-5-weeks of age. if immunoprophylaxis is to be effective, an immunisation method capable of breaking through maternal immunity must be employed. in this study, we ha ... | 2004 | 15063557 |
| excessive porcine circovirus type 2 antibody titres may trigger the development of porcine dermatitis and nephropathy syndrome: a case-control study. | in a case-control study, the role of porcine circovirus 2 (pcv2) and putative co-factors in the development of porcine dermatitis and nephropathy syndrome (pdns) were investigated. pigs with and without pdns were examined for macroscopic lesions and histopathology. in addition, organs and tissues were collected at necropsy and examined for the presence of fibrinous deposits (immune complexes), cd8+ cells, and for the presence of bacterial and viral infections. results from pdns cases were compar ... | 2004 | 15066723 |
| response of white leghorn chickens of various genetic lines to infection with avian leukosis virus subgroup j. | in experiment 1, chickens from various white leghorn experimental lines were inoculated with strain adol-hcl of subgroup j avian leukosis virus (alv-j) either as embryos or at 1 day of age. at various ages, chickens were tested for alv-j induced viremia, antibody, and packed cell volume (pcv). also, at 4 and 10 wk of age, bursal tissues were examined for avian leukosis virus (alv)-induced preneoplastic lesions with the methyl green-pyronine (mgp) stain. in experiment 2, chickens harboring or lac ... | 2004 | 15077798 |
| pathogenesis of postweaning multisystemic wasting syndrome caused by porcine circovirus 2: an immune riddle. | postweaning multisystemic wasting syndrome (pmws) is a disease of pigs first recognised in north america in 1997 and subsequently reported worldwide that is caused by porcine circovirus 2 (pcv2), a member of the family circoviridae. the most consistent feature of pmws is a generalized depletion of lymphocytes. secondary infections with opportunistic organisms are common. there is evidence that the destruction of thymic lymphocytes has a central role in the pathogenesis of pmws. pigs with pmws ha ... | 2004 | 15098103 |
| identification of the essential and non-essential transcription units for protein synthesis, dna replication and infectious virus production of porcine circovirus type 1. | a plasmid-based transfection system capable of yielding infectious porcine circovirus type 1 (pcv1) was established and mutational analysis was conducted to investigate the involvement of each viral transcription unit in protein synthesis, dna replication and progeny virus production. during pcv1 replication in pk15 cells, twelve viral-specific rnas are synthesized. they include the capsid protein rna ( cr), eight rep-associated rnas ( rep, rep', rep3a, rep3b, rep3c-1, rep3c-2, rep3c-3 and rep3c ... | 2004 | 15098111 |
| infection studies on human cell lines with porcine circovirus type 1 and porcine circovirus type 2. | the lack of human donor organs in allotransplantation has led to a proposal for the use of porcine tissues and organs as alternative therapeutic material for humans. besides immunological problems like graft rejection, one of the major concerns is the transmission of porcine microorganisms as viruses, bacteria and fungi to a human recipient. | 2004 | 15099209 |
| epidemiological study on porcine circovirus type 2 (pcv2) infection in the european wild boar (sus scrofa). | porcine circovirus type 2 (pcv2) is considered as the causative agent of postweaning multisystemic wasting syndrome (pmws) in domestic pigs, where the virus is ubiquitous as evidenced by serological surveys. we present the results of the first nationwide sero-survey on the presence of pcv2 antibodies in european wild boars, and report the first pmws case in a wild boar from spain. sera from 656 hunter harvested wild boars from 45 different geographical sites and 22 additional imported animals we ... | 2004 | 15099500 |
| lack of an effect of a commercial vaccine adjuvant on the development of postweaning multisystemic wasting syndrome (pmws) in porcine circovirus type 2 (pcv2) experimentally infected conventional pigs. | the objective of this study was to evaluate the effect of a commercial vaccine adjuvant on the clinical and pathological outcome of pcv2 experimentally infected 8 to 9-week-old conventional pigs. forty-four pigs were divided into four groups: non-infected control pigs, pigs that received a vaccine adjuvant, pigs inoculated with pcv2, and pigs inoculated with pcv2 together with the vaccine adjuvant. infection was monitored until 69 days post-inoculation (pi). some pcv2 inoculated pigs had hyperth ... | 2004 | 15099505 |
| in vitro and in vivo characterization of an infectious clone of a european strain of porcine circovirus type 2. | the aim of this study was to describe the generation of a pcv2 (porcine circovirus type 2) infectious clone (pic-pcv2) and its infectivity under in vitro and in vivo conditions. the constructed pic-pcv2 contained the whole pcv2 genome from a german isolate together with a partial duplication of 467 bp. pk-15 cells were transfected with pic-pcv2 and an indirect immune fluorescence assay (ifa) was performed 7 days post-transfection. the pcv2 cap gene was expressed in approximately 20 % of the cult ... | 2004 | 15105543 |
| development of an elisa based on the baculovirus-expressed capsid protein of porcine circovirus type 2 as antigen. | the genome of porcine circovirus type 2 (pcv2) contains two major open reading frames, which have been shown to encode the virus capsid and replication-associated proteins. the capsid protein is a major structural protein of the virus; it can be a suitable target antigen for detecting pcv2-specific antibodies to monitor pcv2 infection. to produce the antigen, the capsid protein coding sequence was cloned into a baculovirus transfer vector, and a recombinant capsid (rc) protein of pcv2 was expres ... | 2004 | 15107550 |
| systemic cytokine profile in feeder pigs suffering from natural postweaning multisystemic wasting syndrome (pmws) as determined by semiquantitative rt-pcr and flow cytometric intracellular cytokine detection. | postweaning multisystemic wasting syndrome (pmws) is an economically important disease in pigs caused by porcine circovirus type 2 (pcv2). development of this disease is presumably associated with an impairment of the immune system. we, therefore, investigated the systemic expression of relevant cytokines (il-1, il-2, il-4, il-6, il-8, il-10, il-12p40, tnf-alpha, ifn-gamma) and il-2ralpha at mrna (semiquantitative rt-pcr) and at protein level (flow cytometric intracellular cytokine detection aft ... | 2004 | 15113655 |
| characteristics of porcine circovirus-2 replication in lymphoid organs of pigs inoculated in late gestation or postnatally and possible relation to clinical and pathological outcome of infection. | in this study, the characteristics of porcine circovirus-2 (pcv2) replication (infectious virus titrations, distribution, and immunophenotyping of infected cells) in lymphoid organs were examined and related to the development of clinical signs and histological lesions in 26 piglets that had been inoculated with pcv2 either in utero or at 1 day of age. piglets inoculated in utero at 92 or 104 gestational days (n = 12) were collected by caesarean section at term and either sacrificed immediately ... | 2004 | 15152830 |
| postweaning multisystemic wasting syndrome: a review of aetiology, diagnosis and pathology. | this review paper concentrates on the aetiology, diagnosis, and pathological aspects of postweaning multisystemic wasting syndrome (pmws). pmws was first recognized in canada in 1996 as a new emerging disease which caused wasting in postweaned pigs. since then, pmws has been recognized in pigs in many countries. the syndrome is caused by a dna virus referred to as porcine circovirus 2 (pcv2), which is classified in the family circoviridae. pmws primarily occurs in pigs between 25 and 120 days of ... | 2004 | 15158207 |
| 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. | 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-f ... | 2004 | 15163723 |
| detection and genetic typing of type 2 porcine circoviruses in archived pig tissues from the uk. | porcine circovirus 2 (pcv-2) is implicated as the causative agent of post-weaning multisystemic wasting syndrome (pmws) and is also associated with porcine dermatitis and nephropathy syndrome (pdns). the recent emergence of epidemic pmws in the united kingdom was predated by sporadic cases of pdns dating back to the early 1980's. the aim of this study was to investigate whether pcv-2 dna was present in archival tissues, and if so, to investigate the relatedness of these viruses with contemporary ... | 2004 | 15168203 |
| identification of an octanucleotide motif sequence essential for viral protein, dna, and progeny virus biosynthesis at the origin of dna replication of porcine circovirus type 2. | a plasmid-based transfection system capable of generating infectious porcine circovirus type 2 (pcv2) was established. this system was then used in mutagenesis studies to investigate the involvement of a "conserved" nonanucleotide (which constitutes a portion of the loop sequence) located at the origin of dna replication of pcv2 with respect to viral protein synthesis, dna self-replication, and progeny virus production. the results demonstrated that an octanucleotide (agtattac) embedded in the l ... | 2004 | 15183050 |
| characterization of porcine circovirus type 2 in taiwan. | in an effort to understand the genetic diversity of porcine circovirus type 2 (pcv2) and the prevalence of pcv2 infection in taiwanese herds, we have sequenced the complete genomes from pcv2-infected specimens and individually measured the antibody titer against pcv2 from pigs reared in taiwan between the years 2000 and 2002. a total of 623 specimens originating from pigs displaying varied clinical signs were screened with the polymerase chain reaction (pcr). results showed that 309 pigs (49.6%) ... | 2004 | 15187354 |
| postweaning multisystemic wasting syndrome (pmws) in the philippines: porcine circovirus type 2 (pcv2) detection and characterization. | four swine facilities located in northern luzon, in the philippines, showed lesions and clinical signs similar to those described in post weaning multisystemic wasting syndrome (pmws). post-mortem and histopathological examination revealed the presence of typical lymphoid lesions caused by porcine circovirus type 2 (pcv2). an in situ hybridization (ish) technique allowed the detection of pcv2 nucleic acid associated with the lesions in target tissues. pcv2 dna from paraffin embedded tissues was ... | 2004 | 15187364 |
| detection and genetic characterization of porcine circovirus type 2 (pcv2) in pigs from croatia. | porcine circovirus type 2 (pcv2) from the circoviridae family has recently been associated with two serious diseases of swine, post-weaning multisystemic wasting syndrome (pmws) and porcine dermatitis and nephropathy syndrome (pdns). during 2002, several outbreaks of clinical disease in pigs with weights ranging from 10 to 70 kg occurred on four farms in different locations in croatia. the signs were consistent with pmws and pdns. apart from progressive weight loss, pneumonia and/or diarrhoea, m ... | 2004 | 15196907 |
| the presence of co-infections in pigs with clinical signs of pmws in the netherlands: a case-control study. | in this study, 60 pigs with clinical signs of post-weaning multisystemic wasting syndrome (pmws) from 20 different pig herds and 180 control pigs (without clinical signs of pmws) were examined to get more insights into the frequencies of porcine circovirus 2 infections and the presence of co-infections in pigs with and without clinical signs of pmws in the netherlands. porcine circovirus type 2 was detected in 100% of the pigs with clinical signs of pmws by virus isolation and/or pcr and in 50% ... | 2004 | 15196908 |
| molecular characterization of penicillium chrysogenum virus: reconsideration of the taxonomy of the genus chrysovirus. | molecular cloning and complete nucleotide sequencing of penicillium chrysogenum virus (pcv) dsrnas indicated that pcv virions contained four dsrna segments with sizes of 3562, 3200, 2976 and 2902 bp. each dsrna segment had unique sequences and contained a single large open reading frame (orf). in vitro translation of transcripts derived from full-length cdna clones of pcv dsrnas yielded single products of sizes similar to those predicted from the deduced amino acid sequences of the individual or ... | 2004 | 15218197 |
| multiplex pcr for rapid detection of pseudorabies virus, porcine parvovirus and porcine circoviruses. | a multiplex pcr (mpcr) assay was developed and subsequently evaluated for its effectiveness as a means to simultaneously detect multiple viral infections of swine. specific primers for each of four common dna viruses, namely, pseudorabies virus (prv), porcine circovirus type i (pcv1), porcine circovirus type ii (pcv2), and porcine parvovirus (ppv), were used for testing procedure. the assay was shown to be highly sensitive in that as little as 10(-4) ng of each of the respective amplicons (appro ... | 2004 | 15223125 |
| eucaryotic expression of the nucleocapsid protein gene of porcine circovirus type 2 and use of the protein in an indirect immunofluorescence assay for serological diagnosis of postweaning multisystemic wasting syndrome in pigs. | the purpose of this study was to develop a sensitive, rapid, and inexpensive immunofluorescence assay (ifa) using a recombinant porcine circovirus type 2 (pcv2) nucleocapsid protein for the serological detection of pcv2-specific antibodies in pig sera. the viral nucleocapsid protein encoded by the pcv2 orf2 gene has recently been identified as the most immunoreactive viral protein that carries type-specific antigenic determinants. the orf2 sequence of the iaf-2897 strain of pcv2 has been cloned ... | 2004 | 15242949 |
| epitope mapping of the major capsid protein of type 2 porcine circovirus (pcv2) by using chimeric pcv1 and pcv2. | type 2 porcine circovirus (pcv2) is associated with postweaning multisystemic wasting syndrome in pigs, whereas the genetically related type 1 pcv (pcv1) is nonpathogenic. in this study, seven monoclonal antibodies (mabs) against pcv2-orf2 capsid protein were generated, biologically characterized, and subsequently used to map the antigenic sites of pcv2 capsid protein by using infectious pcv dna clones containing pcv1/pcv2-orf2 chimeras. the pcv1/pcv2-orf2 chimeras were constructed by serial del ... | 2004 | 15254185 |
| genome sequence analysis of 10 dutch porcine circovirus type 2 (pcv-2) isolates from a pmws case-control study. | the factors responsible for the emergence of post-weaning multisystemic wasting syndrome (pmws) as an epidemic disease with significant impact upon the pig industry are not all known. porcine circovirus type 2 (pcv-2) has been shown to be necessary but not sufficient for the expression of pmws. retrospective serological and molecular surveys have shown that pcv-2 was widespread and was maintained with only occasional reports of sporadic pmws in the 30 year period prior to the recent emergence of ... | 2004 | 15276779 |
| expression of monocyte chemoattractant protein-1 and macrophage inflammatory protein-1 in porcine circovirus 2-induced granulomatous inflammation. | the expression of monocyte chemoattractant protein-1 (mcp-1) and macrophage inflammatory protein-1 (mip-1) in granulomatous inflammation of lymph nodes was determined in 1-day-old piglets inoculated intranasally with porcine circovirus 2 (pcv2). the methods used were reverse transcription-polymerase chain reaction (rt-pcr), granulomatous lesion scoring, and in-situ hybridization. maximum mcp-1 expression and mip-1 expression were observed at 17 and 21 days post-inoculation (dpi), respectively. g ... | 2004 | 15276851 |
| [disinfectant tests at 20 and 10 degrees c to determine the virucidal activity against circoviruses]. | to evaluate virucidal activity against porcine circovirus type 2 (pcv2), four disinfectants were tested under laboratory conditions. as basis to perform the testing the "guidelines for testing chemical disinfectants" of the german veterinary association (dvg-guidelines) were applied. for simulation of field conditions, the tests were carried out in virus carrier tests, at 20 and 10 degrees c, and under protein load (40% foetal calf serum (fcs) in virus suspension). for disinfection of pcv2 at 20 ... | 2004 | 15287578 |
| palindrome regeneration by template strand-switching mechanism at the origin of dna replication of porcine circovirus via the rolling-circle melting-pot replication model. | palindromic sequences (inverted repeats) flanking the origin of dna replication with the potential of forming single-stranded stem-loop cruciform structures have been reported to be essential for replication of the circular genomes of many prokaryotic and eukaryotic systems. in this study, mutant genomes of porcine circovirus with deletions in the origin-flanking palindrome and incapable of forming any cruciform structures invariably yielded progeny viruses containing longer and more stable pali ... | 2004 | 15308698 |
| genetic similarity between porcine circovirus type 2 isolated from the first reported case of pmws in south africa and north american isolates. | | 2004 | 15338708 |
| features of cell degeneration and death in hepatic failure and systemic lymphoid depletion characteristic of porcine circovirus-2-associated postweaning multisystemic wasting disease. | tissue section replicates from lymphoid tissues and livers of gnotobiotic swine were examined by immunohistochemistry for the colocalization of porcine circovirus-2 (pcv-2) nucleocapsid and terminal deoxynucleotidyl transferase (tdt)-mediated incorporation of biotinylated nucleotides (utp) onto the 3'-exposed hydroxyl groups (nick end labeling) nuclear deoxyribonucleic acid (tunel), a marker for apoptosis. single- and dually stained replicates from uninfected controls, subclinically affected pcv ... | 2004 | 15347819 |
| enteritis associated with porcine circovirus 2 in pigs. | this report describes the diagnosis of porcine circovirus 2 (pcv2)-associated enteritis in 6 weaned pigs without postweaning multisystemic wasting syndrome by histopathology, virus isolation, and in situ hybridization. the most unique lesions were granulomatous inflammation affecting peyer's patches, characterized by infiltrates of epithelioid macrophages and giant multinucleated cells. large, multiple, basophilic or amphophilic, grape-like intracytoplasmic inclusion bodies were often seen in th ... | 2004 | 15352548 |
| an attempt to render oocytes and embryos free from the porcine circovirus type 2 after experimental in vitro exposure. | the purpose of this study was to investigate the possibility of rendering oocytes and embryos free of porcine circovirus type 2 (pcv2). groups of cumulus oocytes complexes, cumulus free oocytes, and embryos 3 to 5 d post breeding were exposed to pcv2 (10(5) tcid50/ml) prior to disinfection by washing and different combinations of enzymatic treatments. the study suggests that under the in vitro conditions used, standard washing procedures with, or without, trypsin or incorporating pronase or hyal ... | 2004 | 15352549 |
| one for all: newer combination vaccines in practice. | as new combination vaccines are approved, practices must consider whether to switch. the decision is likely to be complex, involving everything from re-education of staff to recalculating the bottom line. at some point, however, change will be inevitable, driven principally by the need to add new vaccines to the schedule. in fall 2004, practitioners will be adding two doses of inactivated influenza vaccine to the infant schedule. more communities will be adding two doses of hepatitis a vaccine, ... | 2004 | 15354602 |
| apoptosis in lymphoid organs of pigs naturally infected by porcine circovirus type 2. | 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 hybridizat ... | 2004 | 15448345 |
| assessing the risk potential of porcine circoviruses for xenotransplantation: consensus primer-pcr-based search for a human circovirus. | an important issue with respect to virus safety in xenotransplantation is the search for human analogues of porcine viruses, because transmission of a porcine virus followed by recombination with a related human virus may lead to a new emerging virus of unknown pathogenicity, host range and virulence. in case of circoviruses, two types of porcine circovirus (pcv1 and pcv2) are described, but the existence of an analogous human circovirus has not yet been investigated. | 2004 | 15479465 |
| detection and in vitro and in vivo characterization of porcine circovirus dna from a porcine-derived commercial pepsin product. | non-pathogenic porcine circovirus type 1 (pcv1) and pathogenic pcv2 are widespread in swine herds. in this study, the detection and characterization of pcv1 and pcv2 dna from porcine-derived commercial pepsin are reported. the complete genomic sequences of the pepsin-derived pcv1 and pcv2 share 76 % nucleotide sequence identity with each other and 95-99 % identity with respective north american pcv1 and pcv2 isolates. however, the pcv-contaminated pepsin lacks infectivity in pk-15 cells. to furt ... | 2004 | 15483254 |
| porcine circovirus as a possible cause of postweaning wasting in pigs in switzerland. | postweaning wasting is a major worldwide problem in pig production, particularly with respect to the disease termed postweaning multisystemic wasting syndrome (pmws). in addition to wasting, pmws symptoms include respiratory distress, diarrhoea, pallor and occasional cases of jaundice. the causative agent is porcine circovirus type 2 (pcv-2). the objective of the present study was to determine the significance of pmws and similar conditions in switzerland. a total of 72 weaned piglets from 26 fa ... | 2004 | 15526602 |
| prevalence of porcine circovirus type 2 in aborted fetuses and stillborn piglets. | a retrospective study of natural cases of abortion, recorded between october 2000 and september 2002, was made to determine the prevalence of abortions associated with porcine circovirus type 2 (pcv-2). the virus was detected by pcr, immunohistochemistry and in situ hybridisation. a total of 46 (13.1 per cent) of 350 aborted fetuses and stillborn piglets were positive for pcv-2 by pcr, and the virus was detected in fetuses at all stages of gestation. viral antigen was detected in macrophages fro ... | 2004 | 15537144 |
| quantitation of porcine circovirus type 2 isolated from serum/plasma and tissue samples of healthy pigs and pigs with postweaning multisystemic wasting syndrome using a taqman-based real-time pcr. | porcine circovirus type 2 (pcv2) has been linked to several disease syndromes during the last decade. in this context, postweaning multisystemic wasting syndrome (pmws) has emerged as a significant disease. as most pig herds are infected with pcv2, the determination of viral load in animals may be useful in discriminating between healthy and pmws pigs. a taqman-based real-time pcr for quantitation of pcv2 in serum/plasma and tissue samples was established. a standard curve was created from seria ... | 2004 | 15542141 |
| experimental reproduction of postweaning multisystemic wasting syndrome in pigs by dual infection with mycoplasma hyopneumoniae and porcine circovirus type 2. | the objectives of this study were to investigate the interactions between mycoplasma hyopneumoniae and porcine circovirus type 2 (pcv2) and to establish a model for studying the pathogenesis of and testing intervention strategies for the control of pcv2-associated porcine respiratory disease complex (prdc). sixty-seven pigs were randomly assigned to four groups. group 1 (n=17) pigs served as controls, group 2 (n=17) pigs were inoculated with m. hyopneumoniae, group 3 (n=17) pigs were dual infect ... | 2004 | 15557072 |