| viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus. | one-day-old gnotobiotic piglets were inoculated intranasally with in vitro passaged porcine circovirus 1 (pcv-1), pcv-2, and porcine parvovirus (ppv) alone or in combination (pcv-1/pcv-2, pcv-1/ppv, and pcv-2/ppv). piglets were evaluated for 1) the development of porcine postweaning multisystemic wasting syndrome (pmws), 2) distribution of viral antigens by immunochemistry, and 3) viremia and the presence of viral dna in nasal and ocular secretions and feces. all single agent-infected piglets an ... | 2000 | 10810990 |
| development of probes to differentiate porcine circovirus types 1 and 2 in vitro by in situ hybridization. | porcine circovirus type 1 (pcv1), a pk-15 cell line contaminant, and porcine circovirus type 2 (pcv2), associated with post-weaning multisystemic wasting syndrome (pmws), are genetically and antigenically related. several techniques have been developed to detect pcv, including in situ hybridization (ish). previously reported probes used for ish may hybridize with both pcv1 and pcv2 nucleic acids. we attempted to produce probes for ish that can detect and differentiate pcv2 from pcv1 in pcv-infec ... | 2000 | 10865154 |
| xenotransplantation and the potential risk of xenogeneic transmission of porcine viruses. | the clinical success of allotransplantation and the shortage of donor organs have led to a proposal for the use of animal organs as alternative therapeutic materials for humans. in that regard, swine are preferable to non-human primates as a source of donor organs. while applications for clinical trials for xenotransplantation have not yet been received in canada, several trials have already been authorized in the united states. a major concern, however, is the potential for xenogeneic transmiss ... | 2000 | 11041495 |
| cloning and sequencing of columbid circovirus (cocv), a new circovirus from pigeons. | the complete nucleotide sequence of columbid circovirus (cocv) isolated from pigeons is described. cocv was amplified using a consensus primer pcr approach directed against conserved sequences within the rep genes of vertebrate circoviruses. the genome of cocv is circular and 2037 nt in size. it displays 55% homology to the genome of psittacine beak and feather disease virus and is more distantly related (< 40% homology) to porcine circovirus type 1 and 2. two major open reading frames were iden ... | 2000 | 11205099 |
| replication of porcine circovirus type 1 requires two proteins encoded by the viral rep gene. | the rep gene of porcine circovirus type 1 (pcv1) is indispensable for replication of viral dna. truncation or introduction of point mutations into four conserved sequence motifs led to inactivation of rep as replication initiator. transcription of rep starts at nucleotide 767 +/- 10 bp. an intron (nucleotides 1176 to 1558) is removed by splicing. this leads to synthesis of a truncated protein, which was termed rep' (19.2 kda). because of a frameshift, the last 48 amino acids of rep' deviate from ... | 2001 | 11162799 |
| retrospective serological survey of antibodies to porcine circovirus type 1 and type 2. | a retrospective serological survey was performed to determine the presence of antibodies to porcine circovirus type 1 (pcv1) and porcine circovirus type 2 (pcv2) in serum samples collected from sows at slaughterhouses in canada in 1985, 1989, and 1997. each serum sample was tested by indirect immunofluorescence on pcv-free pk15 cells, on pcv1-infected pk15 cells and on pcv2-infected pk15 cells. for the 3 years studied, sera positive to pcv1 and pcv2 were identified and the number of sera positiv ... | 2000 | 10935885 |
| serum antibodies to porcine circovirus type 1 and type 2 in pigs with and without pmws. | | 2000 | 10909911 |
| differentiation of porcine circovirus 1 and 2 in formalin-fixed, paraffin-wax-embedded tissues from pigs with postweaning multisystemic wasting syndrome by in-situ hybridisation. | non-radioactive digoxigenin (dig)-labelled probes that can differentiate porcine circovirus (pcv) 1 from pcv2 in formalin-fixed, paraffin-wax-embedded tissues by in-situ hybridisation were developed. a 349 base pair (bp) dna fragment from open reading frame (orf) 1 of pcv1 and a 481 bp dna fragment from orf2 of pcv2 generated by polymerase chain reaction (pcr) were used as pcv1 and pcv2 probes, respectively. a specific dig-labelled pcv1 dna probe did not hybridise with pcv2-infected pk-15 cells ... | 2001 | 11676625 |
| production, characterisation and applications of monoclonal antibodies to porcine circovirus 2. | the production, preliminary characterisation and applications of monoclonal antibodies (mabs) against six porcine circovirus 2 isolates are described. a total of 14 stable hybridomas were produced, of which 7 were characterised. all of the mabs characterised were of igg isotype. all the mabs tested reacted by iif with acetone-fixed cell cultures infected with pcv2 isolates from canada, france, spain, denmark, usa and uk. no cross-reactivity with a porcine circovirus 1 field isolate was demonstra ... | 2001 | 11448029 |
| rep and rep' protein of porcine circovirus type 1 bind to the origin of replication in vitro. | genome replication of porcine circovirus type 1 (pcv1) relies upon expression of the full-length protein rep and a spliced isoform (rep'), and the presence of a 111-bp genomic fragment comprising the origin of replication. using an electrophoretic mobility shift assay (emsa), the capability of both rep proteins to bind to partial fragments of the origin of replication of pcv1 was investigated in vitro. both proteins formed complexes with double-stranded dna origin fragments containing a stem-loo ... | 2001 | 11878884 |
| detection of porcine circovirus types 1 and 2 in serum and tissue samples of pigs with and without postweaning multisystemic wasting syndrome. | presence of porcine circovirus type 1 (pcv1) and pcv2 was studied in sera and superficial inguinal lymph nodes from postweaning multisystemic wasting syndrome (pmws)-affected and non-pmws-affected pigs by using in situ hybridization and pcr. pcv1 and pcv2 were found in less than 3% and more than 50% of the samples, respectively. the most sensitive technique and site was pcr in superficial inguinal lymph nodes, but in situ hybridization correlated better with presence of characteristic lesions. | 2002 | 11980975 |
| association of porcine circovirus 2 with reproductive failure in pigs: a retrospective study, 1995-1998. | in order to determine if vertically transmitted porcine circovirus (pcv) has played a role in reproductive failure in pigs in areas of endemic infection, archival fixed tissues were examined by polymerase chain reaction (pcr) and immunohistochemistry. tissues tested were from routine cases of abortion or reproductive failure submitted between 1995 and 1998 to the diagnostic laboratory at the western college of veterinary medicine, saskatoon. they originated from 29 high-health herds in the provi ... | 2001 | 11467183 |
| clinical and pathological observations on pigs with postweaning multisystemic wasting syndrome. | the aim of this work was to characterise the lesions and agents present in clinically normal and clinically affected pigs on a farm during an outbreak of postweaning multisystemic wasting syndrome (pmws), and to evaluate the diagnostic techniques for detecting porcine circovirus type 2 (pcv-2) and other microorganisms. four pigs in the early stage and 11 pigs in the late stage of the disease, and eight clinically normal pigs were necropsied. samples of lymphoid tissue and serum were also obtaine ... | 2001 | 11594382 |
| infectious agents identified in pigs with multifocal interstitial nephritis at slaughter. | one kidney was taken from each of 100 pigs at slaughter; 50 had gross lesions of multifocal interstitial nephritis and 50 had no gross lesions. forty-nine of the affected kidneys had lesions that were characterised by the presence of either a few randomly distributed or numerous widely disseminated pale foci, 1 to 3 mm in diameter, on the cortical surface (white-dotted kidneys). microscopically, these focal inflammatory lesions often had a distinct lymphofollicular pattern (follicular nephritis) ... | 2002 | 11871667 |
| analysis of transcription of porcine circovirus type 1. | porcine circovirus type 1 (pcv1) contains two major open reading frames encoding the replication initiator proteins, rep and rep', and the structural protein, cap. the promoters of these two genes (p(cap) and p(rep)) have been mapped. p(cap) is located within the rep open reading frame (nt 1328-1252). p(rep) has been mapped to the intergenic region immediately upstream of the rep gene (nt 640-796) and overlaps the origin of replication of pcv1. although binding of both rep gene products to a fra ... | 2002 | 12388810 |
| seroprevalence of porcine circovirus type 2 in swine populations in canada and costa rica. | porcine circovirus (pcv) was recently divided into 2 antigenically distinct types that differ (65% amino acid identity) in the protein encoded by open reading frame 2 (orf2). porcine circovirus 1 is apparently non-pathogenic and, in contrast, pcv2 is associated with porcine multisystemic wasting syndrome (pmws). our objective was to determine the extent of exposure of normal pigs in canada and costa rica to pcv2. recombinant dna techniques were used to produce an antigen from orf2 of pcv2 that w ... | 2002 | 12418777 |
| 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 |
| 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 |
| 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 |
| 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 |
| double in situ hybridization for simultaneous detection and differentiation of porcine circovirus 1 and 2 in pigs with postweaning multisystemic wasting syndrome. | double in situ hybridization using a digoxigenin-labelled porcine circovirus 1 (pcv1) and biotinylated pcv2 probe, was developed for the simultaneous detection and differentiation of pcv1 and pcv2 in formalin-fixed, paraffin-embedded tissues from pigs with postweaning multisystemic wasting syndrome. the combination of an alkaline phosphatase conjugated antidigoxigenin system with alkaline phosphatase conjugated streptavidin-biotin system allowed identification of pcv1 and/or pcv2. no evidence of ... | 2002 | 12505399 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| mutational analysis of the direct tandem repeat sequences at the origin of dna replication of porcine circovirus type 1. | mutational analysis was conducted to investigate the role of the nucleotide sequences flanking the stem-loop palindromic structure at the origin of dna replication of porcine circovirus type 1 (pcv1) with respect to self-dna replication and progeny virus generation. the results demonstrated that the a-rich sequence to the left of the palindrome is non-essential for virus replication. although a set of four hexanucleotide (h) sequences to the right of the palindrome (organized in two tandem repea ... | 2005 | 15993915 |
| analysis of the subcellular localization of the proteins rep, rep' and cap of porcine circovirus type 1. | porcine circovirus type 1 (pcv1) encodes two major orfs. the cap gene comprises the major structural protein of pcv, the rep gene specifies rep and rep', which are both essential for initiating the replication of the viral dna. rep corresponds to the full-length protein, whereas rep' is a truncated splice product that is frame-shifted in its c-terminal sequence. in this study, the cellular localization of pcv1-encoded proteins was investigated by immune fluorescence techniques using antibodies a ... | 2005 | 16168452 |
| ultrastructural alterations in human blood leukocytes induced by porcine circovirus type 1 infection. | swine infectious pathogens, especially viruses, represent a potential public health risk associated with the use of pig tissues for xenotransplantation in humans. we hypothesized that porcine circovirus type i (pcv-1) may infect human mononuclear cells, resulting in ultrastructural alterations of the target cells. | 2005 | 16202070 |
| regeneration of the replication-associated proteins tandem direct repeat recognition nucleotide sequence at the origin of dna replication of porcine circovirus type 1. | four copies of a hexanucleotide (h) sequence are located to the right of the palindrome at the origin of dna replication of the porcine circovirus type 1 (pcv1) genome. these sequences are organized in two direct tandems, the proximal h1/h2 and the distal h3/h4 repeats, and they have been shown to be binding sites for the essential rep and rep' proteins. previous work demonstrated that infectious pcv1 virion can accommodate a variable number of h sequences at the origin of dna replication. in th ... | 2006 | 16300812 |
| detection of rampant nucleotide reversion at the origin of dna replication of porcine circovirus type 1. | mutational analysis was conducted to investigate the involvement of the "loop-sequence" (which is flanked by a pair of 11-nucleotide inverted repeats) at the origin of dna replication of porcine circovirus type 1 with respect to viral protein synthesis, dna self-replication and progeny virus production. the results demonstrated that an octanucleotide (a1g2t3a4t5t6a7c8) embedded in the loop is essential for viral dna replication. similar to previous work with porcine circovirus type 2, this octan ... | 2005 | 15708589 |
| identification of pig circovirus type 2 in new zealand pigs. | interest in porcine circovirus has been stimulated by the recent emergence of postweaning multisystemic wasting syndrome (pmws) in pigs and the potential use of pig organs for xenotransplantation in humans. porcine circovirus type 1 (pcv1) is considered to be widespread in pigs but nonpathogenic. circovirus type 2 (pcv2) is a similar virus but has been differentiated only recently as a separate type. high tissue concentrations of pcv2 are associated with lesions in pmws cases, but the etiologica ... | 2005 | 15808691 |
| demonstration of nicking/joining activity at the origin of dna replication associated with the rep and rep' proteins of porcine circovirus type 1. | the replication of porcine circovirus type 1 (pcv1) is thought to occur by rolling-circle replication (rcr), whereby the introduction of a single-strand break generates a free 3'-hydroxyl group serving as a primer for subsequent dna synthesis. the covalently closed, single-stranded genome of pcv1 replicates via a double-stranded replicative intermediate, and the two virus-encoded replication-associated proteins rep and rep' have been demonstrated to be necessary for virus replication. however, a ... | 2006 | 16775310 |
| lack of evidence of porcine circovirus type 1 and type 2 infection in piglets with congenital tremors in korea. | | 2005 | 15816185 |
| detection of porcine circovirus type 1 in commercial pig vaccines using polymerase chain reaction. | the absence of extraneous viruses is a requirement in the quality control of vaccines for veterinary use in the european pharmacopoeia. a polymerase chain reaction (pcr) assay for the detection of porcine circovirus type 1 (pcv1) and type 2 (pcv2) was evaluated in 18 commercial porcine vaccines. since vaccine components may contain pcr enhancers or inhibitors, 13 of the studied vaccines (used as diluents) were subsequently spiked with different dilutions of pcv2 and tested by pcr. although pcv2 ... | 2006 | 16624728 |
| infectivity of porcine circovirus 1 and circovirus 2 in primary porcine hepatocyte and kidney cell cultures. | infectivity of porcine circovirus (pcv) 1 and pcv2 was examined in primary porcine hepatocyte culture by comparing that of pcv in primary kidney cell culture. the virus titer of pcv2-infected hepatocyte cultures was higher than that of the pcv1-infected hepatocyte cultures and the pcv-infected kidney cell cultures. the number of virus-positive cells was most abundant in pcv2-infected hepatocyte cultures as determined by immunohistochemistry and/or in situ hybridization. the results of our data s ... | 2006 | 16520543 |
| mapping of the nuclear localization signals in open reading frame 2 protein from porcine circovirus type 1. | porcine circovirus type 1 (pcv1) contains two major open reading frames encoding the replication-associated proteins and the major structural capsid (cap) protein. pcv1 cap has an n-terminus carrying several potential monopartite or bipartite nuclear localization signals (nls). the contribution of these partially overlapping motifs to nuclear importing was identified by expression of mutated pcv1 cap versions fused to enhanced green fluorescent protein (egfp). the c-terminus truncated pcv1 cap-e ... | 2008 | 18180855 |
| rapid detection of porcine circovirus type 2 by loop-mediated isothermal amplification. | a method of loop-mediated isothermal amplification (lamp) was employed to develop a rapid and simple detection system for porcine circovirus type 2 (pcv2). the amplification could be finished in 60 min under isothermal condition at 64 degrees c by employing a set of four primers targeting the cap gene of pcv2. the lamp assay showed higher sensitivity than the conventional pcr, with a detection limit of five copies per tube of purified pcv2 genomic dna. no cross-reactivity was observed from the s ... | 2008 | 18355932 |
| functional analysis of cis- and trans-acting replication factors of porcine circovirus type 1. | the replication proteins rep and rep' of porcine circovirus type 1 (pcv1) are both capable of introducing and resealing strand discontinuities at the viral origin of dna replication in vitro underlying genome amplification by rolling-circle replication. the pcv1 origin of replication encompasses the minimal binding site (mbs) of the rep and rep' proteins and an inverted repeat with the potential to form a stem-loop. in this study, both elements of the pcv1 origin were demonstrated to be essentia ... | 2007 | 17360750 |
| inhibition of porcine circovirus type 1 and type 2 production in pk-15 cells by small interfering rnas targeting the rep gene. | porcine circovirus type 1 (pcv1) and type 2 (pcv2) are two genotypes of porcine circovirus. both of them are presumed to be widespread in the swine population. currently, there is no specific treatment for their infections. rna interference (rnai) is a sequence-specific rna degradation mechanism mediated by small interfering rna (sirna), which represents a possible therapeutic application for the treatment of viral infections. in this study, three sirna expression plasmids (ps-repa, ps-repb and ... | 2007 | 17467930 |
| [construction of infectious dna clone of chimeric porcine circovirus type 1-2 and its immunogenicity in mice]. | to construct infectious dna clone of chimeric porcine circovirus type 1-2. | 2008 | 19062650 |
| porcine circovirus type 2-induced interleukin-10 modulates recall antigen responses. | porcine circovirus type 2 (pcv2) is the necessary agent for the occurrence of post-weaning multisystemic wasting syndrome (pmws) in pigs. it has been suggested that pmws-affected pigs are immunosuppressed and, therefore, more prone to develop co-infections. in this study, we elucidated that pcv2 downregulates in vitro the immune cell functions during recall antigen responses. we showed that pcv2, but not the non-pathogenic porcine circovirus type 1, induces interleukin (il)-10 secretion by monoc ... | 2008 | 18272768 |
| detection and analysis of porcine circovirus type 1 in hungarian wild boars: short communication. | porcine circovirus type 1 (pcv1) is considered to be a non-pathogenic virus detected in cell cultures, vaccines or products used for cell culture preparations, all of them of porcine origin. serological evidence and genetic studies suggested that pcv1 was widespread in domestic pigs. the presence of pcv1 in wild boars in germany was also described using serological methods. this paper reports the first detection of pcv1 in hungarian wild boars. samples were collected at slaughterhouses and proce ... | 2008 | 18401965 |
| nucleotide sequence-based identification of a novel circovirus of canaries. | circovirus-like, spherical particles measuring 16 to 18 nm in diameter were detected in organ homogenates from adult canaries that had died after a short illness characterized by dullness, anorexia, lethargy and feather disorder. a polymerase chain reaction method, based on degenerate primers specific to conserved amino acid sequences in the circovirus replication-associated protein, was used to amplify dna specific to a novel circovirus, tentatively named canary circovirus (ccv). sequence analy ... | 2001 | 19184917 |
| rapid detection of porcine parvovirus dna by sensitive loop-mediated isothermal amplification. | a method of loop-mediated isothermal amplification (lamp) was employed to develop a rapid and simple detection system for porcine parvovirus (ppv) dna. the amplification could be finished in 45 min under isothermal condition at 62 degrees c by employing a set of four primers targeting vp2 gene of ppv. lamp assay showed higher sensitivity than pcr, with a detection limit of 5 copies of ppv genomic dna per reaction. no cross reactivity was observed from the samples of other related viruses includi ... | 2009 | 19428576 |
| a dna miniarray system for simultaneous visual detection of porcine circovirus type 1 (pcv1) and 2 (pcv2) in pigs. | a miniarray system was developed for the simultaneous detection of porcine circovirus type 1 (pcv1) and type 2 (pcv2) in pigs. the system consists of a polymerase chain reaction (pcr) step to amplify target viral dna, followed by detection of the amplified dna using a membrane-anchored probe array and an avidin-alkaline phosphatase (av-ap) indicator system. the lower limit of detection of pcv using the miniarray was 10(1.9) tissue culture infectious dose 50 (tcid(50))/ml and 10(2.08)tcid(50)/ml ... | 2009 | 18651234 |
| characterization of monoclonal antibody against replication-associated protein of porcine circovirus. | the replication-associated (rep) protein of porcine circovirus (pcv) was suggested to play an essential role in the replication and translation of viral dna. in this study, one monoclonal antibody (mab) specific for rep protein of porcine circovirus type 1 (pcv1), two mabs against rep protein of porcine circovirus type 2 (pcv2), and five mabs to both rep protein of pcv1 and pcv2 were generated using, respectively, rep protein of pcv1 and pcv2 expressed in escherichia coli as an immunogen. wester ... | 2009 | 19072659 |
| interaction of the replication proteins and the capsid protein of porcine circovirus type 1 and 2 with host proteins. | porcine circovirus type 2 (pcv2) is an important pathogen in swine, whereas porcine circovirus type 1 (pcv1) is apathogenic. to analyze the interactions between pcv and its host, we have used a yeast two-hybrid assay to identify cellular proteins interacting with cap and rep proteins of both pcv genotypes. six cellular proteins were found to interact with cap (mkrn1, gc1qr, par-4, nap1, npm1 and hsp40) and three with rep (znf265, tdg and vg5q). these interactions were confirmed by co-immunopreci ... | 2009 | 19178923 |
| viral nucleic acids in live-attenuated vaccines: detection of minority variants and an adventitious virus. | metagenomics and a panmicrobial microarray were used to examine eight live-attenuated viral vaccines. viral nucleic acids in trivalent oral poliovirus (opv), rubella, measles, yellow fever, varicella-zoster, multivalent measles/mumps/rubella, and two rotavirus live vaccines were partially purified, randomly amplified, and pyrosequenced. over half a million sequence reads were generated covering from 20 to 99% of the attenuated viral genomes at depths reaching up to 8,000 reads per nucleotides. m ... | 2010 | 20375174 |
| replication of porcine circoviruses. | porcine circoviruses are circular single-stranded dna viruses that infect swine and wild boars. two species of porcine circoviruses exist. porcine circovirus type 1 is non pathogenic contrary to porcine circovirus type 2 which is associated with the disease known as post-weaning multisystemic wasting syndrome. porcine circovirus dna has been shown to replicate by a rolling circle mechanism. other studies have revealed similar mechanisms of rolling-circle replication in plasmids and single-strand ... | 2009 | 19450240 |
| loop-mediated isothermal amplification for rapid detection and differentiation of wild-type pseudorabies and gene-deleted virus vaccines. | a loop-mediated isothermal amplification (lamp) assay was developed specifically for detection and differentiation of pseudorabies virus (prv). one group of primers was designed to detect wild-type strains (i.e., strains with the ge gene) and the other group of primers was designed to detect both prv ge-vaccine and wild-type strains (i.e., strains with the gg gene and with or without the ge gene). after amplification by bst enzyme at a constant temperature of 65 degrees c, a laddering of bright ... | 2010 | 20691214 |
| regulator of g protein signalling 16 is a target for a porcine circovirus type 2 protein. | interaction studies have suggested that the non-structural protein encoded by open reading frame 3 (orf3) of porcine circovirus type 2 (pcv2) binds specifically to a regulator of g protein signalling (rgs) related to human rgs16 (hurgs16). the full-length clone of rgs16 was generated from porcine cells and sequence analysis revealed a close relationship to hurgs16 and murine rgs16. in vitro pull-down experiments verified an interaction between porcine rgs16 (porgs16) and orf3 from pcv2. using gs ... | 2009 | 19570954 |
| analysis of porcine circovirus type 1 detected in rotarix vaccine. | a metagenomic analysis of live human vaccines has recently demonstrated the presence of porcine circovirus type 1 (pcv1) dna in the paediatric vaccine rotarix used in the prevention of acute gastroenteritis. using real-time pcr for pcv1, titres of pcv1 dna in several batches of rotarix were found to be in the order of 6-7 log(10) copies per dose. pre-treatment of the reconstituted vaccine with the nuclease benzonase, followed by extraction of nucleic acid and quantification of pcv1 dna by real-t ... | 2010 | 21093497 |
| porcine circoviruses--small but powerful. | when porcine circovirus type 1 (pcv1) was isolated more than 40 years ago as a non-pathogenic contaminant of a porcine kidney cell line, enthusiasm and curiosity kept within reasonable limits. virologists became more interested, when a second variant was isolated and termed pcv2, because pcv2 is linked to postweaning multisystemic wasting disease (pmws), a new emerging multifactorial disease in swine. both pcv1 and pcv2 are small and rather simply organized and express only few proteins. therefo ... | 2009 | 19647885 |
| replacement of the replication factors of porcine circovirus (pcv) type 2 with those of pcv type 1 greatly enhances viral replication in vitro. | porcine circovirus type 1 (pcv1), originally isolated as a contaminant of pk-15 cells, is nonpathogenic, whereas porcine circovirus type 2 (pcv2) causes an economically important disease in pigs. to determine the factors affecting virus replication, we constructed chimeric viruses by swapping open reading frame 1 (orf1) (rep) or the origin of replication (ori) between pcv1 and pcv2 and compared the replication efficiencies of the chimeric viruses in pk-15 cells. the results showed that the repli ... | 2010 | 20573809 |
| the porcine circovirus type 1 in porcine kidney 15 cell line is not transferred to mice lymphoid cells after xenoimplantation into the peritoneal cavity. | the porcine circovirus type 1 (pcv1) has been identified within lymphoid tissues of experimental infected pigs and suggested to induce an immunosuppressive stage in pigs. the virus does not induce a cytophatic effect in the pig-derived cell line pk-15. because pcv1 is prevalent in many pig cells and tissues, the risk of inducing a viral xenozoonosis by pcv1 was raised for the xenoimplantation of pig cells into human hosts. the present work evaluated if pcv1 is able to replicate in mice tissues a ... | 2010 | 20977832 |
| rapid detection of porcine circovirus type 2 using a taqman-based real-time pcr. | porcine circovirus type 2 (pcv2) and the associated disease postweaning multisystemic wasting syndrome (pmws) have caused heavy losses in global agriculture in recent decades. rapid detection of pcv2 is very important for the effective prophylaxis and treatment of pmws. to establish a sensitive, specific assay for the detection and quantitation of pcv2, we designed and synthesized specific primers and a probe in the open reading frame 2. the assay had a wide dynamic range with excellent linearit ... | 2010 | 21192832 |
| investigations of porcine circovirus type 1 (pcv1) in vaccine-related and other cell lines. | porcine circovirus type 1 (pcv1) is highly prevalent in swine and was recently reported in u.s. licensed rotavirus vaccines. since animal-derived raw materials, such as cells, trypsin, and serum, can be a major source of introducing virus contamination in biological products, we have investigated pcv1 in several cell lines obtained from atcc that have broad use in research, diagnostics, or vaccine development. it is expected that these cell lines have been exposed to bovine and porcine viruses d ... | 2011 | 21835219 |
| Productive infection of human hepatocellular carcinoma cells by porcine circovirus type 1. | Porcine circovirus type 1 (PCV1), a small DNA virus in pigs, recently gained its notoriety when commercial human rotavirus vaccines were discovered to be contaminated by infectious PCV1. Here we report, for the first time, definitive evidence of productive PCV1 infection in a subclone of human hepatocellular carcinoma cell line (Huh-7, subclone 10-3). Infectious virus was detected in the lysates of infected Huh-7 cells by immunofluorescent assay (IFA) and can be serially passaged in Huh-7-S10-3 ... | 2011 | 21742002 |
| the porcine circovirus type 1 capsid gene promoter improves antigen expression and immunogenicity in a hiv-1 plasmid vaccine. | one of the promising avenues for development of vaccines against human immunodeficiency virus type 1 (hiv-1) and other human pathogens is the use of plasmid-based dna vaccines. however, relatively large doses of plasmid must be injected for a relatively weak response. we investigated whether genome elements from porcine circovirus type 1 (pcv-1), an apathogenic small ssdna-containing virus, had useful expression-enhancing properties that could allow dose-sparing in a plasmid vaccine. | 2011 | 21299896 |
| detection of porcine circovirus type 1 in commercial porcine vaccines by loop-mediated isothermal amplification. | a loop-mediated isothermal amplification (lamp) method with a real-time monitoring system was developed for the detection of porcine circovirus type 1 (pcv1) in commercial swine vaccines. this method was highly specific for pcv1. no cross-reaction to porcine circovirus type 2, porcine parvovirus, pseudorabies virus, classical swine fever virus, and porcine reproductive and respiratory syndrome virus was observed. the analytical sensitivity of the lamp for pcv1 dna was 10 copies/μl in the case of ... | 2011 | 21948286 |
| absence of porcine circovirus type 1 (pcv1) and high prevalence of pcv 2 exposure and infection in swine finisher herds. | porcine circovirus (pcv) appeared in 1974 as an unidentified, innocuous viral inhabitant of cell cultures and pigs. today pcv1 is a contaminant of some human vaccines, and pcv2 is a major pathogen of swine. pcv1 is reportedly ubiquitous in swine but nonpathogenic. since the interplay of pcv1 and pcv2 in swine might explain variable disease results and shed light on the potential for human exposure, we analyzed in depth the prevalence of pcv1 and pcv2 infection and exposure in the u.s. finishing ... | 2011 | 21352865 |
| Loop-mediated isothermal amplification for detection of porcine circovirus type 2. | ABSTRACT: | 2011 | 22044506 |
| Low levels of diversity among genomes of Porcine circovirus type 1 (PCV1) points to differential adaptive selection between Porcine circoviruses. | Several features related with the evolutionary patterns among all the PCV1 genomes available at GenBank have been analyzed in the present work (diversity, number of genotypes, recombination, saturation, selection, evolutionary rate). The reported results point to low levels of nucleotide and amino acid diversity, low number of positively selected codons and a slow evolution rate. Compared with the other species of the Circoviridae family, the diversity is the lowest reported. This can be related ... | 2012 | 22088213 |
| Use of PCR-based assays for the detection of the adventitious agent porcine circovirus type 1 (PCV1) in vaccines, and for confirming the identity of cell substrates and viruses used in vaccine production. | Safety and quality are important issues for vaccines. Whereas reversion to virulence poses a safety risk with live attenuated vaccines, the potential for the presence of adventitious agents is also an issue of vaccine quality. The recent detection or porcine circovirus type 1 (PCV1) in human vaccines has further highlighted the importance of quality control in vaccine production. The purpose of this study was to use a novel conventional PCR to detect PCV1, and subsequently screen materials used ... | 2012 | 22079617 |
| contamination by porcine circovirus type 1: findings, investigations, and learnings. | conference proceeding proceedings of the pda/fda adventitious viruses in biologics: detection and mitigation strategies workshop in bethesda, md, usa; december 1-3, 2010 guest editors: arifa khan (bethesda, md), patricia hughes (bethesda, md) and michael wiebe (san francisco, ca). | 2011 | 22294584 |
| regulatory approaches for control of viral contamination of vaccines. | conference proceeding proceedings of the pda/fda adventitious viruses in biologics: detection and mitigation strategies workshop in bethesda, md, usa; december 1-3, 2010 guest editors: arifa khan (bethesda, md), patricia hughes (bethesda, md) and michael wiebe (san francisco, ca) improved assurance that vaccines do not contain harmful adventitious agents is expected to enhance public confidence and promote vaccine benefit. the recent discovery of porcine circovirus 1 in some rotavirus vaccines u ... | 2011 | 22294577 |
| detection of a novel circovirus pcv3 in pigs with cardiac and multi-systemic inflammation. | porcine circovirus 2 causes different clinical syndromes resulting in a significant economic loss in the pork industry. three pigs with unexplained cardiac and multi-organ inflammation that tested negative for pcv2 and other known porcine pathogens were further analyzed. | 2016 | 27835942 |
| insulated isothermal reverse transcriptase pcr (iirt-pcr) for rapid and sensitive detection of classical swine fever virus. | classical swine fever (csf) is an oie-listed disease that can have a severe impact on the swine industry. user-friendly, sensitive, rapid diagnostic tests that utilize low-cost field-deployable instruments for csf diagnosis can be useful for disease surveillance and outbreak monitoring. in this study, we describe validation of a new probe-based insulated isothermal reverse transcriptase pcr (iirt-pcr) assay for rapid detection of classical swine fever virus (csfv) on a compact, user-friendly dev ... | 2016 | 25644051 |
| optimization of virus detection in cells using massively parallel sequencing. | massively parallel sequencing (mps)-based virus detection has potential regulatory applications. we studied the ability of one of these approaches, based on degenerate oligonucleotide primer (dop)-polymerase chain reaction (pcr), to detect viral sequences in cell lines known to express viral genes or particles. dop-pcr was highly sensitive for the detection of small quantities of isolated viral sequences. detected viral sequences included nodavirus, bracovirus, and endogenous retroviruses in hig ... | 2014 | 24309095 |
| molecular and infectivity studies of porcine circovirus in vaccines. | this report describes fda's laboratory response to the 2010 reports that porcine circovirus type 1 (pcv-1) dna was present in u.s.-licensed rotavirus vaccines and in cells used to produce inactivated poliovirus vaccines. in the present study, rotarix(®) (glaxosmithkline, rixenxart, belgium) was found to contain full-length pcv-1 genomes that are particle-associated, and cell culture assays in swine testis (st) and pcv-free porcine kidney (pk-15) cells confirmed that pcv-1 sequences in this vacci ... | 2011 | 21569811 |
| Outcome of experimental porcine circovirus type 1 infections in mid-gestational porcine foetuses. | Porcine circovirus type 1 (PCV1) has been described as a non-cytopathic contaminant of the PK-15 cell line. Several experimental infections with PCV1 failed to reproduce disease in pigs. Therefore, PCV1 is generally accepted as non-pathogenic to pigs. To our knowledge, nothing is known about the outcome of PCV1 infections in porcine foetuses. This was examined in the present study. | 2011 | 22018436 |
| an experimental live chimeric porcine circovirus 1-2a vaccine decreases porcine circovirus 2b viremia when administered intramuscularly or orally in a porcine circovirus 2b and porcine reproductive and respiratory syndrome virus dual-challenge model. | commercially available inactivated vaccines against porcine circovirus type 2 (pcv2) have been shown to be effective in reducing pcv2 viremia. live-attenuated, orally administered vaccines are widely used in the swine industry for several pathogens because of their ease of use yet they are not currently available for pcv2 and efficacy. the aims of this study were to determine the efficacy of a live-attenuated chimeric pcv2 vaccine in a dual-challenge model using pcv2b and porcine reproductive an ... | 2011 | 21951266 |
| preclinical detection of porcine circovirus type 2 infection using an ultrasensitive nanoparticle dna probe-based pcr assay. | porcine circovirus type 2 (pcv2) has emerged as one of the most important pathogens affecting swine production globally. preclinical identification of pcv2 is very important for effective prophylaxis of pcv2-associated diseases. in this study, we developed an ultrasensitive nanoparticle dna probe-based pcr assay (undp-pcr) for pcv2 detection. magnetic microparticles coated with pcv2 specific dna probes were used to enrich pcv2 dna from samples, then gold nanoparticles coated with pcv2 specific o ... | 2014 | 24842840 |
| discovery and complete genome sequence of a novel circovirus-like virus in the endangered rowi kiwi, apteryx rowi. | circoviruses are circular, non-enveloped, single-stranded dna viruses around 2000 nucleotides (nt) in length and include the pathogenic species, porcine circovirus 1 and beak and feather disease virus, capable of causing significant morbidity and mortality. this group of viruses may be robust to degradation by external environments, and avian circoviruses are known to move between closely related hosts. using a de novo metagenomic approach, followed by confirmatory pcr, we identify for the first ... | 2016 | 27115421 |
| detection of contaminants in cell cultures, sera and trypsin. | the aim of this study was standardization and application of polymerase chain reaction (pcr) for the detection of contaminants in cell cultures, sera and trypsin. five pcr protocols were standardized to assess the presence of genetic material from mycoplasma, porcine circovirus 1 (pcv1), bovine leukemia virus (blv) or bovine viral diarrhea virus (bvdv) in cell culture samples. pcr reactions for the genes gapdh and beta-actin were used to evaluate the efficiency of nucleic acid extraction. the pc ... | 2013 | 24071554 |
| transformed cell-specific induction of apoptosis by porcine circovirus type 1 viral protein 3. | several members of the family circoviridae have been shown to encode proteins with apoptotic activity. for example, both porcine circovirus type 2 (pcv2) and chicken anemia virus (cav) encode a third viral protein (vp3) that has been shown to be cytotoxic. interestingly, in the case of the cav protein (designated apoptin), apoptosis is specific to transformed cell types. similarities in genome structure and organization suggest that pcv type 1 (pcv1) may also contain a third orf, which codes for ... | 2015 | 25381055 |
| reduction of spiked porcine circovirus during the manufacture of a vero cell-derived vaccine. | porcine circovirus-1 (pcv1) was recently identified as a contaminant in live rotavirus vaccines, which was likely caused by contaminated porcine trypsin. the event triggered the development of new regulatory guidance on the use of porcine trypsin which shall ensure that cell lines and porcine trypsin in use are free from pcv1. in addition, manufacturing processes of biologicals other than live vaccines include virus clearance steps that may prevent and mitigate any potential virus contamination ... | 2014 | 24560672 |
| investigation of a regulatory agency enquiry into potential porcine circovirus type 1 contamination of the human rotavirus vaccine, rotarix: approach and outcome. | in january 2010, porcine circovirus type 1 (pcv1) dna was unexpectedly detected in the oral live-attenuated human rotavirus vaccine, rotarix (glaxosmithkline [gsk] vaccines) by an academic research team investigating a novel, highly sensitive analysis not routinely used for adventitious agent screening. gsk rapidly initiated an investigation to confirm the source, nature and amount of pcv1 in the vaccine manufacturing process and to assess potential clinical implications of this finding. the inv ... | 2013 | 24056737 |
| shedding of porcine circovirus type 1 dna and rotavirus rna by infants vaccinated with rotarix®. | thirty-three infants aged ∼2 months had serial stool samples collected after receipt of rotarix® vaccine dose 1, and were assessed for shedding of porcine circovirus type 1 dna and rotavirus group a rna by molecular methods. we did not find strong evidence that porcine circovirus type 1 replication occurred. porcine circovirus type 1 genome with the same sequence as that in rotarix® was detected in a few infants as late as day ≥ 13; while this timing could suggest there may have been replication ... | 2016 | 27936349 |
| detection of pcv-2 dna in stool samples from infants vaccinated with rotateq®. | rotarix® and rotateq® vaccines have led to a dramatic reduction in rotavirus disease worldwide. however, the detection of porcine circovirus type 1 (pcv-1) and 2 (pcv-2) dna in these vaccines raised some safety concerns. studies examining shedding of rotavirus in stool from rotavirus vaccine recipients have been performed but no published data exist regarding the shedding of pcv virus in stools of vaccinees. the goal of this study was to determine if pcv-1 and/or pcv-2 is shed in the feces of in ... | 2014 | 24104203 |
| genetic adaptation of porcine circovirus type 1 to cultured porcine kidney cells revealed by single-molecule long-read sequencing technology. | porcine circovirus type 1 (pcv1) is a nonpathogenic circovirus, and a contaminant of the porcine kidney (pk-15) cell line. we present the complete and annotated genome sequence of strain szeged of pcv1, determined by pacific biosciences rsii long-read sequencing platform. | 2017 | 28153895 |
| serologic response to porcine circovirus type 1 (pcv1) in infants vaccinated with the human rotavirus vaccine, rotarix™: a retrospective laboratory analysis. | in 2010, porcine circovirus type 1 (pcv1) material was unexpectedly detected in the oral live-attenuated human rotavirus (rv) vaccine, rotarix™ (gsk vaccines, belgium). an initial study (nct01511133) found no immunologic response against pcv1 in 40 vaccinated infants. as a follow-up, the current study (nct02153333), searched for evidence of post-vaccination serologic response to pcv1 in a larger number of archived serum samples. unlike the previous study, serum anti-pcv1 antibodies were assessed ... | 2017 | 27657348 |
| evaluation of the use of non-pathogenic porcine circovirus type 1 as a vaccine delivery virus vector to express antigenic epitopes of porcine reproductive and respiratory syndrome virus. | we previously demonstrated that the c-terminus of the capsid gene of porcine circovirus type 2 (pcv2) is an immune reactive epitope displayed on the surface of virions. insertion of foreign epitope tags in the c-terminus produced infectious virions that elicited humoral immune responses against both pcv2 capsid and the inserted epitope tags, whereas mutation in the n terminus impaired viral replication. since the non-pathogenic porcine circovirus type 1 (pcv1) shares similar genomic organization ... | 2016 | 26555162 |
| a taqman-based real-time pcr for detection and quantification of porcine parvovirus 4. | porcine parvovirus 4 (ppv4) is a dna virus, and a member of the parvoviridae family within the bocavirus genera. it was detected recently in swine, but its epidemiology and pathology remain unclear. a taqman-based real-time pcr (qpcr) targeting a conserved region of the orf3 gene of ppv4 was developed. the qpcr detection limit was 9.5 × 10(1) dna copies/μl. there was no cross-reaction with porcine parvovirus, torque teno virus 1, torque teno virus 2, porcine circovirus type 1, porcine circovirus ... | 2015 | 25813599 |
| optimal transfection methods and comparison of pk-15 and dulac cells for rescue of chimeric porcine circovirus type 1-2. | a chimeric porcine circovirus type 1-2 (pcv1-2) infectious dna clone has low transfection efficiency and exhibits low levels of proliferation. electroporation and lipofection parameters were optimized for pk-15 and dulac cells with the purpose of increasing the efficiency for rescuing infectious pcv1-2. titers of pcv1-2 in dulac cells were 100-fold higher than those in pk-15 cells following transfection. the electroporation efficiency into dulac cells was high when three 400 μs pulses at 250 v w ... | 2014 | 25125130 |
| lack of genetic diversity in newly sequenced porcine circovirus type 1 strains isolated 20 years apart. | the complete genome sequences of a porcine circovirus type 1 (pcv1) strain isolated in 1990 and one isolated in 2011 were obtained and compared to the sequences of other available pcv1 isolates. phylogenetic analyses revealed very low genetic diversity among these viruses, indicating an advanced state in the evolution of pcv1. | 2014 | 24723701 |
| comparative evaluation of conventional polymerase chain reaction (pcr), with loop-mediated isothermal amplification and sybr green i-based real-time pcr for the quantitation of porcine circovirus-1 dna in contaminated samples destined for vaccine production. | porcine circovirus type1 (pcv1), described initially as a contaminant of a porcine kidney cell line, is ubiquitous within the swine population the presence of pcv1 in porcine cell lines can lead to contamination during both human and porcine vaccine production. therefore, a rapid, specific, sensitive and practical method is needed for the detection of pcv1 in bio-products. the aim of this study was to compare three assays in their ability to accurately quantify pcv1 virus in biological samples, ... | 2013 | 23538038 |
| attenuation of porcine circovirus type-2b by replacement with the rep gene of porcine circovirus type-1. | porcine circovirus type-2 (pcv2) is the primary causative agent of porcine circovirus-associated diseases and has 4 main orfs, orf1 (rep gene), orf2 (cap gene), orf3 within orf1, and orf4, which is overlapped with orf3, and 1 origin (ori) of replication located between orf1 and orf2. the chimeric pcv1-2, containing the pcv2 capsid, pcv1 rep, and ori genes, is attenuated in pigs. in order to verify the role of the rep gene or ori in the virulence of pcv2, 3 chimeric viruses [pcv2b-ori1 (pcv1 ori ... | 2013 | 23454919 |
| highly permissive subclone of the porcine kidney cell line for porcine circovirus type 2 production. | this study established a highly permissive and decontaminated cell line for growing porcine circovirus type 2 (pcv2). a porcine kidney-15 cell line (pk-15) contaminated with porcine circovirus type 1 (pcv1) was decontaminated by neutralizing with rabbit anti-pcv1 hyperimmune serum. subsequently, by limiting dilution and cell subcloning, four pcv1-free monoclonal cells were grown to monolayers. each cell clone and pk-15 cell were infected with pcv2. the pkkc cell clone yielded up to 10(6.8)tcid(5 ... | 2013 | 23219808 |
| extraneous agent detection in vaccines--a review of technical aspects. | the quality and safety of commercial vaccines have a profound importance. contrary to all precautions and efforts the use of biological material in vaccine development and production may lead to potential contamination of the vaccines with known and unknown extraneous agents (eas). in veterinary field official lists of eas have been compiled as legal framework to describe the potential agents, which must be tested during manufacture of vaccines. nevertheless, detection of known and unknown conta ... | 2012 | 22575785 |
| identification of three new type-specific antigen epitopes in the capsid protein of porcine circovirus type 1. | porcine circovirus type 1 (pcv1) has been identified as a contaminant of porcine kidney cell line (pk-15). serological evidence and genetic studies have suggested that pcv1 is widespread in domestic pigs. in this study, monoclonal antibodies (mabs) and polyclonal antibodies (pabs) were generated against a recombinant pcv1 cap protein (pcv1-cap), which was expressed using the baculovirus system. pepscan analysis was used to identify epitopes on the pcv1-cap with mabs and pabs. three linear b-cell ... | 2012 | 22437253 |
| multi-platform analysis reveals a complex transcriptome architecture of a circovirus. | in this study, we used pacific biosciences rs ii long-read and illumina hiscansq short-read sequencing technologies for the characterization of porcine circovirus type 1 (pcv-1) transcripts. our aim was to identify novel rna molecules and transcript isoforms, as well as to determine the exact 5'- and 3'-end sequences of previously described transcripts with single base-pair accuracy. we discovered a novel 3'-utr length isoform of the cap transcript, and a non-spliced cap transcript variant. addi ... | 2017 | 28549855 |
| genetic variation analysis of pcv1 strains isolated from guangxi province of china in 2015. | porcine circovirus type 1 (pcv1) was discovered in 1974 as a contaminant of a porcine kidney (pk-15) cell line and was generally accepted to be nonpathogenic. but recently it was shown to cause lesions in experimentally infected pig fetuses. serological evidence and genetic studies suggested that pcv1 was widespread in domestic pigs. thus, the molecular epidemiology and genetic variation of pcv1 are still necessary to understand. | 2018 | 29415728 |
| analysis of putative orf3 gene within porcine circovirus type 2. | porcine circovirus type 2 (pcv2) is associated with postweaning multisystemic syndrome in pigs, whereas the ubiquitous related porcine circovirus type 1 (pcv1) is nonpathogenic. corroborating an earlier observation in pcv2, rep and rep' proteins encoded by orf1 are essential for the initiation of pcv2 replication. cap protein encoded by orf2 has a potential causative role in the initiation of pcv2 replication and contains a type-specific epitope. the putative orf3 of pcv2 oriented in the opposit ... | 2012 | 22741582 |
| porcine circovirus (pcv) removal by q sepharose fast flow chromatography. | the recently discovered contamination of oral rotavirus vaccines led to exposure of millions of infants to porcine circovirus (pcv). pcv was not detected by conventional virus screening tests. regulatory agencies expect exclusion of adventitious viruses from biological products. therefore, methods for inactivation/removal of viruses have to be implemented as an additional safety barrier whenever feasible. however, inactivation or removal of pcv is difficult. pcv is highly resistant to widely use ... | 2015 | 24039195 |
| investigation of porcine circovirus contamination in human vaccines. | dna from porcine circovirus type 1 (pcv1) and 2 (pcv2) has recently been detected in two vaccines against rotaviral gastroenteritis from manufacturers a and b. we investigated if pcv1 sequences are present in other viral vaccines. we screened seeds, bulks and final vaccine preparations from ten manufacturers using qrt-pcr. we detected 3.8 × 10³ to 1.9 × 10⁷ pcv1 dna copies/milliliter in live poliovirus seeds for inactivated polio vaccine (ipv) from manufacturer a, however, following inactivation ... | 2012 | 22402185 |
| successful removal of porcine circovirus-1 from immunoglobulin g formulated in glycine solution using nanofiltration. | porcine circovirus (pcv) is a potentially harmful virus that has been shown to contaminate biological products. the virus is resistant to many inactivation and/or removal procedures performed during manufacturing. anion exchange chromatography has been shown to be useful for pcv type 1 (pcv1) removal; however, reduction of pcv1 using methods such as heat inactivation, low ph, nanofiltration, uv-c, and gamma irradiation has not been successful. therefore, in this study, we evaluate various condit ... | 2018 | 29122439 |
| porcine circovirus type 1 was undetected in vaccine but could be cultured in the cell substrate of lanzhou lamb rotavirus vaccine. | in 2010, rotarix was found to be contaminated with infectious porcine circovirus type 1 (pcv1). in china, the lanzhou lamb rotavirus (llr) vaccine is the only vaccine used to prevent rotavirus disease. from 2006 to september 2014, more than 54 million doses of llr vaccines have been lot released. it is a safety issue whether pcv1 is present in the llr vaccine. although the cell substrate of llr, bovine kidney (bk), is different from that of rotarix, we have investigated the cell's permissivity f ... | 2018 | 29165219 |