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chimeric viruses containing the n-terminal ectodomains of gp5 and m proteins of porcine reproductive and respiratory syndrome virus do not change the cellular tropism of equine arteritis virus.equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv) are members of family arteriviridae; they are highly species specific and differ significantly in cellular tropism in cultured cells. in this study we examined the role of the two major envelope proteins (gp5 and m) of eav and prrsv in determining their cellular tropism. we generated three viable eav/prrsv chimeric viruses by swapping the n-terminal ectodomains of these two proteins from prrsv ia1107 str ...201222739441
porcine reproductive and respiratory syndrome virus induces autophagy to promote virus replication.an increasing number of studies demonstrate that autophagy, an intrinsic mechanism that can degrade cytoplasmic components, is involved in the infection processes of a variety of pathogens. it can be hijacked by various viruses to facilitate their replication. in this study, we found that prrsv infection significantly increases the number of double- or single-membrane vesicles in the cytoplasm of host cells in ultrastructural analysis. our results showed the lc3-i was converted into lc3-ii after ...201222739997
the polymorphism analysis of cd169 and cd163 related with the risk of porcine reproductive and respiratory syndrome virus (prrsv) infection.porcine reproductive and respiratory syndrome virus (prrsv) could infect porcine alveolar macrophages (pam), and the cd169 and cd163 are identified as critical receptors on the surface of pam, but whether the single nucleotide polymorphisms (snps) of these genes could influence the infection is remain unclear. in this study, we identified totally 6 snps for cd169 (g1640t, c1654a, c4175t) and cd163 (g2277a, a2552g and c2700a), and evaluated their associations with prrsv infection using two classi ...201222740140
antiviral activity of phage display selected peptides against porcine reproductive and respiratory syndrome virus in vitro.porcine reproductive and respiratory syndrome is an important infectious disease of pigs and has a significant harmful effect on the livestock industry, especially in china. prrsv orf1b gene encodes primary proteins which play a vital role during prrsv replication. in this paper, various 12-amino-acid peptides were displayed. these peptides could bind to the polymerase and helicase of prrsv orf1b protein, respectively, in which p9 exerted the highest antiviral activity with an ic50 of 56 μm, and ...201222743126
immune responses in pigs induced by recombinant dna vaccine co-expressing swine il-18 and membrane protein of porcine reproductive and respiratory syndrome virus.in this study, two dna vaccines, which express the membrane (m) protein of porcine respiratory and reproductive syndrome virus (prrsv) (pegfp-m) and co-express both m and swine il-18 (pegfp-il18-m), were constructed and their abilities to induce humoral and cellular responses in piglets were comparatively evaluated. experimental results showed that both recombinant dna vaccines could not elicit neutralizing antibodies in the immunized piglets. however, both dna vaccines elicited th1-biased cellu ...201222754326
evaluation of the long-term effect of air filtration on the occurrence of new prrsv infections in large breeding herds in swine-dense regions.airborne transmission of porcine reproductive and respiratory syndrome virus (prrsv) is a risk factor for the infection of susceptible populations. therefore, a long‑term sustainability study of air filtration as a means to reduce this risk was conducted. participating herds (n = 38) were organized into 4 independent cohorts and the effect of air filtration on the occurrence of new prrsv infections was analyzed at 3 different levels from september 2008 to january 2012 including the likelihood of ...201222754642
post-transcriptional control of type i interferon induction by porcine reproductive and respiratory syndrome virus in its natural host cells.porcine reproductive and respiratory syndrome virus (prrsv) is not only a poor inducer of type i interferon but also inhibits the efficient induction of type i interferon by porcine transmissible gastroenteritis virus (tgev) and synthetic dsrna molecules, poly i:c. however, the mechanistic basis by which prrsv interferes with the induction of type i interferon in its natural host cells remains less well defined. the purposes of this review are to summarize the key findings in supporting the post ...201222754646
regulatory t cells in arterivirus and coronavirus infections: do they protect against disease or enhance it?regulatory t cells (t(regs)) are a subset of t cells that are responsible for maintaining peripheral immune tolerance and homeostasis. the hallmark of t(regs) is the expression of the forkhead box p3 (foxp3) transcription factor. natural regulatory t cells (nt(regs)) are a distinct population of t cells that express cd4 and foxp3. ntregs develop in the thymus and function in maintaining peripheral immune tolerance. other cd4(+), cd4(-)cd8(-), and cd8(+)cd28(-) t cells can be induced to acquire r ...201222754651
n-linked glycosylation of gp5 of porcine reproductive and respiratory syndrome virus is critically important for virus replication in vivo.it has been proposed that the n-linked glycan addition at certain sites in gp5 of porcine reproductive and respiratory syndrome virus (prrsv) is important for production of infectious viruses and viral infectivity. however, such specific n-linked glycosylation sites do not exist in some field prrsv isolates. this implies that the existence of gp5-associated glycan per se is not vital to the virus life cycle. in this study, we found that mutation of individual glycosylation sites at n30, n35, n44 ...201222761373
pathogenicity and distribution of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs.the pathogenesis of highly pathogenic porcine reproductive and respiratory syndrome virus (prrsv) strain (hun4) is poorly understood. therefore, highly pathogenic prrsv strain (hun4) and its derivative strain (hun4-f112) (obtained by propagation in marc145 cells for 112 passages) were inoculated into a total of 48 prrsv-sero-negative pigs (age: 4-5 weeks) by the intranasal route. virological, pathological and in situ hybridization analyses were performed. the results exhibited that pigs infected ...201322762447
characterization of thymus atrophy in piglets infected with highly pathogenic porcine reproductive and respiratory syndrome virus.our previous study has demonstrated that piglets infected with highly pathogenic prrsv (hp-prrsv) induced significant thymus atrophy. the aim of this study was to further investigate the lesions in thymus of piglets infected with hp-prrsv or prrsv and the changes of thymic t cell populations. the lesions were evaluated for the thymus/body weight ratios, pathological changes and virus load in thymus, apoptosis and ultrastructure of thymocytes. the result showed that thymus/body weight ratios of h ...201222763175
detection and typing of highly pathogenic porcine reproductive and respiratory syndrome virus by multiplex real-time rt-pcr.porcine reproductive and respiratory syndrome (prrs) causes economic losses in the pig industry worldwide, and prrs viruses (prrsv) are classified into the two distinct genotypes "north american (na, type 2)" and "european (eu, type 1)". in 2006, a highly pathogenic na strain of prrsv (hp-prrsv), characterized by high fever as well as high morbidity and mortality, emerged in swine farms in china. therefore, a real-time reverse transcription polymerase chain reaction (rt-qpcr) assay specific for ...201222768042
ligation of fc gamma receptor iib enhances levels of antiviral cytokine in response to prrsv infection in vitro.prrsv infection ade facilitates the attachment and internalization of the virus onto its host cells, such as monocytes and macrophages, through fc receptor-mediated endocytosis. fcγriib is the only inhibitory receptor with a tyrosine-based inhibitory motif (itim) in its cytoplasmic tail, where counters the "itam triggered" activation signals and down-regulates phagocytosis. however, porcine fcγriib's role in the antiviral immune response to prrsv infection has not been studied. in this study, ou ...201222771209
highly pathogenic porcine reproductive and respiratory syndrome virus gp5 b antigenic region is not a neutralizing antigenic region.in 2006, highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) caused great economic losses emerged in china and continues to be a threat for the pig industry. b antigenic region (ar) ((37)shl/fqliynl(45)) of gp5 was considered to be a major linear neutralizing ar in prrsv classical strains. however, peptide-purified antibodies against this ar did not neutralize prrsv in a recent report. compared with classical prrsv, one amino acid mutation (l/f(39)→ i(39)) was found ...201222771210
location of t-cell epitopes in nonstructural proteins 9 and 10 of type-ii porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) is a significant swine pathogen which exhibits considerable sequence diversity. in an attempt to identify highly conserved t-cell epitopes contained in proteins of this virus, we examined heptadecamer peptides spanning the sequence of the prrsv nonstructural proteins (nsps) 9 and 10, both of which are highly conserved, for their ability to elicit a recall proliferative and interferon-gamma response in peripheral blood mononuclear cells ...201222771938
porcine ear necrosis syndrome: a preliminary investigation of putative infectious agents in piglets and mycotoxins in feed.the aim of this study was to identify the causative factors of porcine ear necrosis syndrome (pens) in 72 pigs, 5.5-10 weeks in age housed on nine farms. biopsy samples of ear pinnae were collected from all piglets for bacteriology, histopathology and in situ hybridization for porcine circovirus type 2 (pcv2). at the same time, serum samples were taken for serological analysis and viral pcr, and feed was sampled for mycotoxin analysis. the initial lesion of pens seemed to be a focal epidermal ne ...201222784419
outbreaks of highly pathogenic porcine reproductive and respiratory syndrome in jiangxi province, china.in 2007, herds of pigs in jiangxi province, china experienced outbreaks of a severe form of suspected porcine reproductive and respiratory syndrome (prrs) characterized by high fever, high morbidity and mortality in animals of different ages. 152 swine sera and 42 tissues (consisting of liver, lung, lymph node and kidney) from five herds of pigs were collected. pigs were diagnosed as infected with a highly pathogenic form of the prrs virus (prrsv) based on elisa and reverse transcriptase polymer ...201222784793
expression and serological reactivity of nsp7 protein of prrs genotype i virus.the aim of this work was to express recombinant nonstructural nsp7 protein of european genotype of porcine reproductive and respiratory syndrome virus and to evaluate its diagnostic sensitivity and specificity in serological diagnostics of the disease. the gene coding for nsp7 protein was expressed in escherichia coli cells and purified by imac. serological reactivity of purified protein was assessed on a panel of swine sera in indirect elisa test. serum samples originated from prrs positive far ...201222795686
usp18 restricts prrsv growth through alteration of nuclear translocation of nf-κb p65 and p50 in marc-145 cells.although the functions of porcine respiratory and reproductive syndrome virus (prrsv) proteins are increasingly understood, the roles of host factors in modifying infection are less well understood. growing evidence places deubiquitination at the core of a multitude of regulatory processes, ranging from cell growth to innate immune response and health, such as cancer, degenerative and infectious diseases. this report provides further information on the functional role of the porcine ubiquitin-sp ...201222796444
[recombinant porcine lung surfactant protein a inhibits porcine reproductive and respiratory syndrome virus infection into host cells in vitro].to investigate the antiviral activity of porcine lung surfactant protein a (sp-a) to porcine reproductive and respiratory syndrome virus (prrsv) in vitro.201222803352
porcine reproductive and respiratory syndrome virus: interlaboratory ring trial to evaluate real-time reverse transcription polymerase chain reaction detection methods.to compare the real-time reverse transcription quantitative polymerase chain reaction (rt-qpcr) assays used for the diagnosis of porcine reproductive and respiratory syndrome virus (prrsv), a europe-wide interlaboratory ring trial was conducted. a variety of prrsv strains including north american (na) and european (eu) genotype isolates were analyzed by the participants. great differences regarding qualitative diagnostics as well as analytical sensitivity were observed between the individual rt- ...201222807507
recent progress in studies of arterivirus- and coronavirus-host interactions.animal coronaviruses, such as infectious bronchitis virus (ibv), and arteriviruses, such as porcine reproductive and respiratory syndrome virus (prrsv), are able to manifest highly contagious infections in their specific native hosts, thereby arising in critical economic damage to animal industries. this review discusses recent progress in studies of virus-host interactions during animal and human coronavirus and arterivirus infections, with emphasis on ibv-host cell interactions. these interact ...201222816036
downregulation of antigen-presenting cells in tonsil and lymph nodes of porcine reproductive and respiratory syndrome virus-infected pigs.porcine reproductive and respiratory syndrome virus (prrsv) can persist in different organs of infected pigs, which suggests a failure in the immune response. antigen-presenting cells (apcs) play a pivotal role in the induction of effective t- and b-cell responses. in this study, we investigated the changes in the different apc subpopulations and t- and b-cell counts in the tonsil, retropharyngeal and mediastinal lymph nodes of pigs experimentally infected with a european prrsv field isolate. ou ...201322816521
tracing the genetic history of porcine reproductive and respiratory syndrome viruses derived from the complete orf 5-7 sequences: a bayesian coalescent approach.to trace the genetic history of porcine reproductive and respiratory syndrome virus (prrsv), we determined the complete sequences of orfs 5 to 7 of four prrsv isolates. these sequences were analyzed together with published sequences from 146 isolates from various parts of the world using a bayesian coalescent approach as well as bayesian inference and maximum-likelihood methods. all of the european-type (eu-type) viruses were classified into one of two groups or unclassified (4 isolates), while ...201222825696
comparison of the virulence of european and north american genotypes of porcine reproductive and respiratory syndrome virus in experimentally infected pigs.the objective of this study was to compare the virulence of korean types 1 and 2 porcine reproductive and respiratory syndrome virus (prrsv) isolated from weaned pigs with respiratory disease. affected pigs were within the same herd and animals infected with type 2 virus had significantly higher mean rectal temperatures than those with type 1 virus between days 2 and 9 post-inoculation (p<0.05). similarly, mean serum viral titres, expressed as tissue culture infective doses 50% (tcid50)/ml, as w ...201322831992
evaluation of a dna vaccine candidate co-expressing gp3 and gp5 of porcine reproductive and respiratory syndrome virus (prrsv) with interferon α/γ in immediate and long-lasting protection against hp-prrsv challenge.porcine reproductive and respiratory syndrome virus (prrsv) has become one of the most economically important diseases to the global pork industry. current vaccination strategies only provide a limited protective efficacy. in this study, a dna vaccine, pvax1(©)-α-γ-gp35, co-expressing gp3 and gp5 of prrsv with interferon α/γ was constructed, and its immediate and long-lasting protection against highly pathogenic prrsv (hp-prrsv) challenge were examined in pigs. for immediate protection, the resu ...201222843314
complete genome sequence of a highly pathogenic porcine reproductive and respiratory syndrome virus variant.following the 2006 outbreaks of the highly pathogenic porcine reproductive and respiratory syndrome, the causative agent was identified as the highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv). to investigate whether the hp-prrsv variant continues circulating and accelerating evolution, we sequenced and analyzed the complete genome of the identified hp-prrsv field strain sd16. the sequence data indicate that the hp-prrsv variant continues to prevail and accelerate ...201222843863
identification of nonessential regions of the nsp2 protein of an attenuated vaccine strain (hun4-f112) of highly pathogenic porcine reproductive and respiratory syndrome virus for replication in marc-145 cell.the regions in the middle of nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (prrsv) have been shown to be nonessential for prrsv replication, and these nonessential regions are different in various viral strains.201222856599
complete genome sequence of a novel variant porcine reproductive and respiratory syndrome virus (prrsv) strain: evidence for recombination between vaccine and wild-type prrsv strains.porcine reproductive and respiratory syndrome virus (prrsv) is the etiologic agent of porcine reproductive and respiratory syndrome (prrs), which can evolve continuously by random mutation or intragenic recombination. here we report the complete genomic sequence of a prrsv variant with nucleotide acid deletions and insertions in the nonstructural protein 2 (nsp2) gene and a possible recombination event between a modified live virus (mlv) vaccine strain and a prototype chinese field strain.201222879614
infectious risk factors for individual postweaning multisystemic wasting syndrome (pmws) development in pigs from affected farms in spain and denmark.two prospective longitudinal studies in 13 postweaning multisystemic wasting syndrome (pmws)-affected farms from spain (n=3) and denmark (n=10) were performed. blood samples from pigs were longitudinally collected from 1st week until the occurrence of the pmws outbreak. wasted and healthy age-matched pigs were euthanized, necropsied and histopathologically characterised. pmws diagnosis was confirmed by means of lymphoid lesions and detection of porcine circovirus type 2 (pcv2) in these tissues b ...201222884005
identification of a new unusual length polymorphism of the nucleocapsid protein in porcine reproductive and respiratory syndrome virus.all twenty-nine prrsv orf7 nucleotide sequences obtained from clinical samples originating from the three central european countries austria (n = 7), czech republic (n = 12), and slovakia (n = 10) belonged to type 1, subtype i (eu-1). twenty-seven sequences encoded the typical length of the nucleocapsid protein composed of 128 amino acids. two genetically identical orf7s of prrsv originating from a single farm in slovakia showed a new length polymorphism of the nucleocapsid protein comprising 13 ...201222886536
immunohistochemical expression of il-12, il-10, ifn-α and ifn-γ in lymphoid organs of porcine reproductive and respiratory syndrome virus-infected pigs.despite the numerous studies carried out, the mechanisms used by porcine reproductive and respiratory syndrome (prrs) virus (prrsv) to impair the host immune response are not yet clear. the aim of this study was to determine the expression of il-12, il-10, ifn-α and ifn-γ in lymphoid organs of prrsv experimentally-infected pigs. twenty eight piglets were inoculated with prrsv field isolate 2982 and killed in batches of four at 3, 7, 10, 14, 17, 21 and 24 days post-inoculation (dpi). control anim ...201222889555
preliminary findings of a previously unrecognized porcine primary immunodeficiency disorder.weaned pigs from a line bred for increased feed efficiency were enrolled in a study of the role of host genes in the response to infection with porcine reproductive and respiratory syndrome virus (prrsv). four of the pigs were euthanatized early in the study due to weight loss with illness and poor body condition; 2 pigs before prrsv infection and the other 2 pigs approximately 2 weeks after virus inoculation. the 2 inoculated pigs failed to produce prrsv-specific antibodies. gross findings incl ...201322903400
induction of interleukin-10 is dependent on p38 mitogen-activated protein kinase pathway in macrophages infected with porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) causes reproductive failure and respiratory illness in pigs and usually establishes a persistent infection. previous studies suggested that interleukin-10 (il-10) could play a critical role in prrsv-induced immunosuppression. however, the ability of prrsv to induce il-10 in infected cells is controversial. in this study, we further investigated this issue using prrsv strain ch-1a, which is the first north american genotype strain isolat ...201222909062
use of reverse genetics to develop a novel marker porcine reproductive and respiratory syndrome virus.nucleocapsid (n) protein of porcine reproductive and respiratory syndrome virus (prrsv) is the most abundant viral structural protein with high immunogenicity. previously, the nonessential sequences for virus infectivity were identified at both n and c terminal ends of n protein. here, by means of reverse genetics, a marker virus (v7apma) was generated with a mutant n protein that differs from the wild-type strains (vaprrs, type 2 prrsv). v7apma shows stable inheritance in cell culture and the v ...201222936497
efficient inhibition of porcine reproductive and respiratory syndrome virus replication by artificial micrornas targeting the untranslated regions.a robust artificial microrna (amirna) strategy against porcine reproductive and respiratory syndrome virus (prrsv) was developed by targeting the untranslated regions (utrs). six candidate amirnas targeting the 5' or 3' utr were used for vector construction, and four effective amirnas were selected for further study using a vector transfection/virus infection assay. in cell cultures stably transfected with the four amirna vectors, expression of the sequence-specific amirnas was confirmed using p ...201322948796
interaction of cellular poly(c)-binding protein 2 with nonstructural protein 1β is beneficial to chinese highly pathogenic porcine reproductive and respiratory syndrome virus replication.non-structural protein1β (nsp1β) of porcine reproductive and respiratory syndrome virus (prrsv) has been recognized to be involved in suppressing the host innate immune response and mediating viral subgenomic mrna transcription. in the present study, we have analyzed the interaction of nsp1β of chinese highly pathogenic prrsv (hp-prrsv) with cellular poly(c)-binding 2 (pcbp2) by means of the yeast two-hybrid screening in a pulmonary alveolar macrophages (pams) cdna library and co-immunoprecipita ...201222951310
role of non-structural protein 2 in the regulation of the replication of the porcine reproductive and respiratory syndrome virus in marc-145 cells: effect of gene silencing and over expression.porcine reproductive and respiratory syndrome (prrs) is an economically important disease in swine-producing areas. many vaccine strategies have been developed to control the disease, but none have yet been completely successful. the development of a cell line that can produce large yields of prrsv vaccine is very necessary. in order to determine the role of nsp2 in the replication of the highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) in marc-145 cells, we used ...201222959006
significance of genetic variation of prrsv orf5 in virus neutralization and molecular determinants corresponding to cross neutralization among prrs viruses.a high rate of genetic and antigenic variability among porcine reproductive and respiratory syndrome viruses (prrsvs) hampers effective prevention and control of the disease caused by prrsv. the major envelope protein (gp5) encoded by the orf5 of prrsv has a critical role in inducing virus neutralizing (vn) antibody and cross protection among different strains of prrsv. this study was conducted to identify sequence elements related to cross neutralization by comparing the orf5 sequences of 69 fi ...201322959007
proteomic characterization of a novel structural protein orf5a of porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) emerged in the late 1980s in both europe and north america is an arterivirus causing great economic losses in the pig industry worldwide. recently, a novel structural protein, orf5a, encoded by an alternative orf of a subgenomic mrna encoding the major envelope glycoprotein, gp5, has been discovered in all arteriviruses, suggesting its important role in arterivirology. the present study attempted to investigate compensatory changes of c ...201222960469
ring test evaluation of the repeatability and reproducibility of a porcine reproductive and respiratory syndrome virus oral fluid antibody enzyme-linked immunosorbent assay.the precision of a porcine reproductive and respiratory syndrome virus (prrsv) oral fluid antibody enzyme-linked immunosorbent assay (elisa) was evaluated by calculating reliability coefficients for assay repeatability (within laboratory) and assay reproducibility (between laboratories). randomly ordered oral fluid samples of known (n = 39) and unknown (n = 224) prrsv antibody status were tested in 12 diagnostic laboratories. each laboratory tested the samples twice, first using an antibody elis ...201222964428
chinese highly pathogenic porcine reproductive and respiratory syndrome virus exhibits more extensive tissue tropism for pigs.the highly pathogenic porcine reproductive and respiratory syndrome virus (prrsv) emerging in china exhibits high fatality to pigs. however, the mechanism related to the increased pathogenicity of the virus remains unclear. in the present study, the differences in tissue tropism between the highly pathogenic prrsv strain (jxwn06) and the low pathogenic prrsv strain (hb-1/3.9) were investigated using prrsv-specific immunohistochemistry (ihc) staining to provide evidence for elucidating possible m ...201222978380
impact of a novel inactivated prrs virus vaccine on virus replication and virus-induced pathology in fetal implantation sites and fetuses upon challenge.preventing congenital infection is important for the control of porcine reproductive and respiratory syndrome (prrs). recently, in our laboratory, an inactivated porcine reproductive and respiratory syndrome virus (prrsv) vaccine has been developed. promising results in young pigs encouraged us to test the vaccine potency to prevent congenital infection. in the present study, the performance of this experimental inactivated vaccine was investigated in pregnant gilts. an advanced protocol was use ...201222980086
dissociation of porcine reproductive and respiratory syndrome virus neutralization from antibodies specific to major envelope protein surface epitopes.glycoprotein 5 (gp5) and membrane (m) protein are the major proteins in the envelope of porcine reproductive and respiratory syndrome virus (prrsv). although viral neutralization epitopes are reported in gp5 and m of type 2 prrsv, their significance as targets of porcine humoral immunity is not well described. thus, we constructed recombinant polypeptides containing ectodomain neutralization epitopes to examine their involvement in porcine antibody neutralization and antiviral immunity. prrsv in ...201222981434
poly(a)-binding protein interacts with the nucleocapsid protein of porcine reproductive and respiratory syndrome virus and participates in viral replication.interactions between host factors and the viral protein play important roles in host adaptation and regulation of virus replication. poly(a)-binding protein (pabp), a host cellular protein that enhances translational efficiency by circularizing mrnas, was identified by yeast two-hybrid screening as a cellular partner for prrsv nucleocapsid (n) protein in porcine alveolar macrophages. the specific interaction of prrsv n protein with pabp was confirmed in infected cells by co-immunoprecipitation a ...201222985629
identification of amino acid residues important for anti-ifn activity of porcine reproductive and respiratory syndrome virus non-structural protein 1.the non-structural protein 1 (nsp1) of porcine reproductive and respiratory syndrome virus is partly responsible for inhibition of type i interferon (ifn) response by the infected host. by performing alanine-scanning mutagenesis, we have identified amino acid residues in nsp1α and nsp1β (the proteolytic products of nsp1) that when substituted with alanine(s) exhibited significant relief of ifn-suppression. a mutant virus (16-5a, in which residues 16-20 of nsp1β were substituted with alanines) en ...201222995188
porcine reproductive and respiratory syndrome virus induces pronounced immune modulatory responses at mucosal tissues in the parental vaccine strain vr2332 infected pigs.porcine reproductive and respiratory syndrome (prrs) is a chronic viral disease of pigs caused by prrs virus (prrsv). the prrsv vr2332 is the prototype north american parental strain commonly used in the preparation of vaccines. goal of this study was to understand missing information on vr2332 induced immune modulation at the lungs and lymphoid tissues, the sites of prrsv replication. pigs were infected intranasally and samples collected at post-infection day (pid) 15, 30, and 60. microscopical ...201322995873
reston virus in domestic pigs in china.historically, reston virus (restv) has been found to be associated with outbreaks of disease only in nonhuman primates. its spread to domestic pigs was reported for the first time in 2008. in this study, we report the discovery, molecular detection, and phylogenetic analysis of reston virus (restv) in domestic pigs in china. a total of 137 spleen specimens from pigs that died after showing typical clinical signs of porcine reproductive and respiratory syndrome (prrs), and for which infection wit ...201422996641
complete genome sequence of two variant porcine reproductive and respiratory syndrome viruses isolated from vaccinated piglets.porcine reproductive and respiratory syndrome virus (prrsv) continues to affect the chinese swine industry. since 2006, variant prrsv strains sharing two unique discontinuous deletions of 30 amino acids in the nonstructural protein nsp2 have become dominant in chinese swine herds and have caused huge economic losses to the swine industry in china. here we report the complete genome sequence of two novel prrsv variants isolated from vaccinated piglets with additional amino acid deletions in nsp2.201222997418
the effect of infection order of porcine circovirus type 2 and porcine reproductive and respiratory syndrome virus on dually infected swine alveolar macrophages.concurrent infection with porcine circovirus type 2 (pcv2) and porcine reproductive and respiratory syndrome virus (prrsv) is known as one of the major causes for porcine respiratory disease complex (prdc). dual infection with pcv2 and prrsv is consistently to have more severe clinical presentations and pulmonary lesions than infection with pcv2 alone or prrsv alone. however, it is not known if dual infections with pcv2 and prrsv in different infection order may lead to different clinical sympto ...201223009687
evolution of quasispecies diversity for porcine reproductive and respiratory syndrome virus under antibody selective pressure.to study the quasispecies diversity of porcine reproductive and respiratory syndrome virus (prrsv), open reading frame 5 (orf5) of strain sd0612 was amplified and cloned. sixty clones of orf5 were sequenced and analyzed with dnastar software. nucleic acid sequence homology was 97.7%-100%, with 78 mutations observed. among these 60 clones, the sequences of 17 clones were identical and recognized as the dominant quasispecies of strain sd0612. evolution of sd0612 quasispecies diversity under antibo ...201223015127
risk factors causing postweaning multisystemic wasting syndrome (pmws) onset in swiss pig farms.postweaning multisystemic wasting syndrome (pmws) was epizoozic between 2003 and 2008 in switzerland. nevertheless, infectious risk factors including porcine reproductive and respiratory syndrome virus (prrsv) were missing at all or were seen only sporadically (enzootic pneumonia and actinobazillosis). in a case-control study, 30 farms with pmws affected pigs were compared to 30 inconspicious farms ("matched pairs"). the case-control allocation was verified by pcv2 dna measurements of 5 healthy ...201223027509
comparison of the efficacy of autogenous inactivated porcine reproductive and respiratory syndrome virus (prrsv) vaccines with that of commercial vaccines against homologous and heterologous challenges.the porcine reproductive and respiratory syndrome virus (prrsv) is a rapidly evolving pathogen of swine. at present, there is a high demand for safe and more effective vaccines that can be adapted regularly to emerging virus variants. a recent study showed that, by the use of a controlled inactivation procedure, an experimental bei-inactivated prrsv vaccine can be developed that offers partial protection against homologous challenge with the prototype strain lv. at present, it is however not kno ...201223031319
exploratory study of torque teno sus viruses in pulmonary inflammatory lesions in pigs.the pathogenic role of torque teno sus viruses 1 (ttsuv1) and 2 (ttsuv2), and their capacity to induce lesions are controversial. ttsuvs have been linked to porcine circovirus diseases (pcvds) and described as cause of mild respiratory lesions in gnotobiotic pigs; moreover, an increased ttsuv prevalence has been found in porcine respiratory disease complex (prdc) affected pigs. in the present study, ttsuv1 and ttsuv2 loads and their prevalence were evaluated in formalin-fixed, paraffin-embedded ...201323031343
risk factors for porcine reproductive and respiratory syndrome virus infection and resulting challenges for effective disease surveillance.this study aimed to identify risk factors for active porcine reproductive and respiratory syndrome virus (prrsv) infection at farm level and to assess the probability of an infected farm being detected through passive disease surveillance in england. data were obtained from a cross-sectional study on 147 farrow-to-finish farms conducted from april 2008-april 2009. the risk factors for active prrsv infection were identified using multivariable logistic regression analysis. the surveillance system ...201223034160
recognition of the different structural forms of the capsid protein determines the outcome following infection with porcine circovirus type 2.porcine circovirus type 2 (pcv2) capsid protein (cp) is the only protein necessary for the formation of the virion capsid, and recombinant cp spontaneously forms virus-like particles (vlps). located within a single cp subunit is an immunodominant epitope consisting of residues 169 to 180 [cp(169-180)], which is exposed on the surface of the subunit, but, in the structural context of the vlp, the epitope is buried and inaccessible to antibody. high levels of anti-cp(169-180) activity are associat ...201223035215
comparative analysis of immune responses following experimental infection of pigs with european porcine reproductive and respiratory syndrome virus strains of differing virulence.porcine reproductive and respiratory syndrome virus (prrsv) is difficult to control due to a high mutation rate and the emergence of virulent strains. the objective of this study was to analyze the immunological and pathological responses after infection with the european subtype 3 strain lena in comparison to subtype 1 strains belgium a and lelystad-ter huurne (lv). sixteen pigs were inoculated per strain, and sixteen pigs with pbs. at days 7 and 21 post-inoculation (p.i.), four pigs per group ...201323036445
production and immunogenicity of chimeric virus-like particles containing porcine reproductive and respiratory syndrome virus gp5 protein.porcine reproductive and respiratory syndrome virus (prrsv) poses a severe threat in swine industry and causes heavy economic losses worldwide. currently, the available vaccines are the inactivated and attenuated virus vaccines, but the use of prrsv in their production raises the issue of safety. we developed a chimeric virus-like particles (vlps) vaccine candidate for prrsv protection. the chimeric vlps was composed of m1 protein from h1n1 influenza virus and a fusion protein, denoted as na/gp5 ...201223036496
cytokine production in immortalized porcine alveolar macrophages infected with porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) is one of the most economically significant viral pathogens for pig production worldwide. prrsv primarily infects cells of the monocyte/macrophage lineage such as porcine alveolar macrophages (pams), and is generally known to suppress normal macrophage function and regulate innate immune responses to viral infection. a continuous prrsv-permissive porcine monocyte-derived cell line was previously generated to facilitate virus propagation ...201223041033
efficient -2 frameshifting by mammalian ribosomes to synthesize an additional arterivirus protein.programmed -1 ribosomal frameshifting (-1 prf) is a gene-expression mechanism used to express many viral and some cellular genes. in contrast, efficient natural utilization of -2 prf has not been demonstrated previously in eukaryotic systems. like all nidoviruses, members of the arteriviridae (a family of positive-stranded rna viruses) express their replicase polyproteins pp1a and pp1ab from two long orfs (1a and 1b), where synthesis of pp1ab depends on -1 prf. these polyproteins are posttransla ...201223043113
dna shuffling of the gp3 genes of porcine reproductive and respiratory syndrome virus (prrsv) produces a chimeric virus with an improved cross-neutralizing ability against a heterologous prrsv strain.porcine reproductive and respiratory syndrome virus (prrsv) is an important swine pathogen. here we applied the dna shuffling approaches to molecularly breed the prrsv gp3 gene, a neutralizing antibodies inducer, in an attempt to improve its heterologous cross-neutralizing ability. the gp3 genes of six different prrsv strains were bred by traditional dna shuffling. additionally, synthetic dna shuffling of the gp3 gene was also performed using degenerate oligonucleotides. the shuffled-gp3-librari ...201223051709
positive inductive effect of il-18 on virus-specific immune responses induced by prrsv-gp5 dna vaccine in swine.two dna vaccines encoding the envelope protein gp5 of porcine reproductive and respiratory syndrome virus (prrsv) alone (pegfp-gp5) and co-encoding gp5 and swine interleukin-18 (il-18) proteins (pegfp-il18-gp5), were constructed and comparatively evaluated for their abilities to induce humoral and cellular responses in piglets. experimental results showed that among all vaccinated groups, the live prrsv vaccine elicited the highest titre of serum neutralizing antibody and the strongest cell-medi ...201323058982
infectiousness of pigs infected by the porcine reproductive and respiratory syndrome virus (prrsv) is time-dependent.the time-dependent transmission rate of porcine reproductive and respiratory syndrome virus (prrsv) and the correlation between infectiousness, virological parameters and antibody responses of the infected pigs were studied in experimental conditions. seven successive transmission trials involving a total of 77 specific pathogen-free piglets were carried out from 7 to 63 days post-inoculation (dpi). a semi-quantitative real time rt-pcr was developed to assess the evolution of the viral genome lo ...201223061672
porcine reproductive and respiratory syndrome virus detection in thailand during 2005-2010 in relation to clinical problems, pig types, regions, and seasons.the objectives of the present study were to determine the prevalence of porcine reproductive and respiratory syndrome virus (prrsv) in thailand between 2005 and 2010. the study was conducted by retrospectively investigating the detection of prrsv from different pig types including boars, sows, piglets, nursery pigs, and fattening pigs from six regions of thailand, i.e., the northern, eastern, northeastern, central, western, and southern parts. the data were obtained from cases submitted to the c ...201323065394
sulfated modification can enhance antiviral activities of achyranthes bidentata polysaccharide against porcine reproductive and respiratory syndrome virus (prrsv) in vitro.achyranthes bidentata polysaccharide (abps) was sulfated using the chlorosulfonic acid-pyridine method. the uv-spectrum of sulfated abps (sabps) was characterized with two different absorbance peaks at 196.3 and 262.8 nm. ft-ir spectrum of sabps exhibited absorption bands at 1236.5 cm(-1) (asymmetrical s=o stretching vibration) and 822.8 cm(-1) (symmetrical c-o-s vibration related to a c-o-so(3) group). anti-prrsv activities of sabps were tested on marc-145 cells by mtt method. the results showe ...201323068136
a sybr green-based real-time rt-pcr assay for simple and rapid detection and differentiation of highly pathogenic and classical type 2 porcine reproductive and respiratory syndrome virus circulating in china.sybr green coupled to melting curve analysis has been suggested to detect rna viruses showing high genomic variability. here, a sybr green-based real-time rt-pcr assay was developed for simultaneous detection and differentiation of highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) and classical type 2 prrsv (c-prrsv). the different strains were identified by their distinctive melting temperatures: 82.98 ± 0.25 °c and 85.95 ± 0.24 °c for hp-prrsvs or 82.74 ± 0.26 °c ...201323070137
identifying an outbreak of a novel swine disease using test requests for porcine reproductive and respiratory syndrome as a syndromic surveillance tool.animal disease monitoring and surveillance are crucial for ensuring the health of animals, humans and the environment. many studies have investigated the utility of monitoring syndromes associated with data from veterinary laboratory submissions, but no research has focused on how negative test results from a veterinary diagnostic laboratory data can be used to improve our knowledge of disease outbreaks. for example, if a diagnostic laboratory was seeing a disproportionate number of negative tes ...201223072647
genomic sequence and virulence comparison of four type 2 porcine reproductive and respiratory syndrome virus strains.porcine reproductive and respiratory syndrome virus (prrsv) is a ubiquitous and costly virus that exhibits substantial sequence and virulence disparity among diverse isolates. in this study, we compared the whole genomic sequence and virulence of 4 type 2 prrsv isolates. among the 4 isolates, sdsu73, mn184, and nadc30 were all clearly more virulent than nadc31, and among the 3 more virulent isolates, there were subtle differences based on viral replication, lung lesions, lymphadenopathy, febrile ...201223073232
attenuation of porcine reproductive and respiratory syndrome virus by molecular breeding of virus envelope genes from genetically divergent strains.molecular breeding via dna shuffling can direct the evolution of viruses with desired traits. by using a positive-strand rna virus, porcine reproductive and respiratory syndrome virus (prrsv), as a model, rapid attenuation of the virus was achieved in this study by dna shuffling of the viral envelope genes from multiple strains. the gp5 envelope genes of 7 genetically divergent prrsv strains and the gp5-m genes of 6 different prrsv strains were molecularly bred by dna shuffling and iteration of ...201323077307
experimental infection of united states swine with a chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus.the pathogenesis of type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) in 10-week old swine in the united states was investigated. rjxwn06, rescued from an infectious clone of chinese hp-prrsv, replicated in swine with at least 100-fold increased kinetics over u.s. strain vr-2332. rjxwn06 caused significant weight loss, exacerbated disease due to bacterial sepsis and more severe histopathological lung lesions in pigs exposed to hp-prrsv than to those infected ...201323079105
porcine reproductive and respiratory syndrome virus infection activates il-10 production through nf-κb and p38 mapk pathways in porcine alveolar macrophages.porcine reproductive and respiratory syndrome virus (prrsv) is an emerging animal virus that has caused high economic losses for the swine industry worldwide. previous in vitro and in vivo studies demonstrated that prrsv infection induces significant production of interleukin 10 (il-10), a pleiotropic cytokine with immuno-modulatory functions involved in host defense. however, the underlying regulatory mechanisms during prrsv remain largely unknown. in the present study, we analyzed the expressi ...201323085400
chemical constituents of arisaema franchetianum tubers.a novel pyrrolidine alkaloid, (2r*,3s*,5s*)-n,2-dimethyl-3-hydroxy-5-(10-phenyldecyl)pyrrolidine (1), and 17 known compounds were isolated from arisaema franchetianum engl. (araceae) tubers. the 17 compounds were bergenin (2), emodin (3), caffeic acid (4), nobiletin (5), 3-o-β-d-galactopyranosyl-hederagenin 28-o-β-d-xylopyranosyl(1 → 6)-β-d-galactopyranosyl ester (6), coniferin (7), qingyangshengenin (8), methylconiferin (9), syringaresinol 4'-o-β-d-glucopyranoside (10), gagaminine (11), perloly ...201323106482
ribavirin efficiently suppresses porcine nidovirus replication.porcine reproductive and respiratory syndrome virus (prrsv) and porcine epidemic diarrhea virus (pedv) are porcine nidoviruses that represent emerging viral pathogens causing heavy economic impacts on the swine industry. although ribavirin is a well-known antiviral drug against a broad range of both dna and rna viruses in vitro, its inhibitory effect and mechanism of action on porcine nidovirus replication remains to be elucidated. therefore, the present study was conducted to determine whether ...201323108045
molecular characterization, expression profiles, and association analysis with hematologic parameters of the porcine hpse and hpse2 genes.heparan sulfate (hs), which consists of repeating disaccharide units, plays an essential role in inflammation and viral infections. heparanase (encoded by the hpse gene) can cleave the hs chains of heparan sulfate proteoglycans (hspgs), which are known to be important participants in immune responses. hpse2 (heparanase 2) is a homologous gene of hpse. to investigate the functions of hs, which is the primary receptor of the porcine reproductive and respiratory syndrome virus (prrsv), the two gene ...201323109057
genetic diversity characterization of porcine reproductive and respiratory syndrome virus isolates in romania, based on phylogenetic analysis.porcine reproductive and respiratory syndrome (prrs) is a disease produced by the (prrs) virus, characterized by endemic evolution in the majority of countries, which remains in actuality being a permanent threat to health and economic free farms, as well as for those infected. the aim of this study was to evaluate the genetic diversity of romanian prrsv isolates from the four most important pig farms in romania by comparing the nucleotide sequences obtained for orf5 and orf7 with a wide range o ...201223109899
analysis of the swine tracheobronchial lymph node transcriptomic response to infection with a chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) is a major pathogen of swine worldwide. emergence in 2006 of a novel highly pathogenic prrsv (hp-prrsv) isolate in china necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nodes (tbln) 13 days post-infection with hp-prrsv rjxwn06, prrsv strain vr-2332 or sham inocula. rna from each was prepared for next-generation sequencing. amplified library constructs were directly sequenced and a ...201223110781
oral immunogenicity of porcine reproductive and respiratory syndrome virus antigen expressed in transgenic banana.porcine reproductive and respiratory syndrome virus (prrsv) is a persistent threat of economically significant influence to the swine industry worldwide. recombinant dna technology coupled with tissue culture technology is a viable alternative for the inexpensive production of heterologous proteins in planta. embryogenic cells of banana cv. 'pei chiao' (aaa) have been transformed with the orf5 gene of prrsv envelope glycoprotein (gp5) using agrobacterium-mediated transformation and have been con ...201323116484
complete genome sequence of a novel highly pathogenic porcine reproductive and respiratory syndrome virus variant.highly pathogenic porcine reproductive and respiratory syndrome (hp-prrs) emerged in china in 2006, and hp-prrs virus (hp-prrsv) has evolved continuously. here, the complete genomic sequence of a novel hp-prrsv field strain, jx, is reported. the present finding will contribute to further studies focusing on the evolutionary mechanism of prrsv.201223118452
the survey of porcine teschoviruses in field samples in china with a universal rapid probe real-time rt-pcr assay.a real-time reverse transcription polymerase chain reaction (rt-pcr) based on taqman was established and evaluated for quantitative detection of porcine teschoviruses (ptvs). a pair of primers and a taqman probe targeting on the highly conserved sequence of the 5'-untranslated region (5'-utr) of one to 11 serotypes of ptv were designed. standard plasmid dna containing pcr amplification of the 5'-utr were constructed and used to develop the real-time rt-pcr. the results indicated that the real-ti ...201323138413
expression of short peptide by an improved isocaudamer tandem repeat strategy.an improved isocaudamer tandem repeat strategy for the production of short functional peptide was demonstrated in the study. the coding sequence of short peptide was codon optimized, and two isocaudamers were induced into the end of coding sequence. by re-cutting with isocaudamers and re-ligating, the coding sequence of short peptide in the expression vector was increased in a multiple manner (21, 22, 23, 24, 25 …….). in the present study, an 8 amino-acidresidue peptide of porcine reproductive a ...201323140616
antibody repertoire development in fetal and neonatal piglets. xv. porcine circovirus type 2 infection differentially affects serum igg levels and antibodies to orf2 in piglets free from other environmental factors.porcine circovirus type 2 (pcv2) is an important pathogen in the porcine respiratory disease complex (prdc) and its persistence may be due to dysregulation of systemic immunity. we examined this contention using isolator piglets. we present data on ig levels in serum and bronchio-alveolar lavage (bal), on antibody response to pcv2 and to tnp conjugates used as model antigens in 48 pcv2-infected isolator piglets. we compared these to data from tnp-immunized isolator piglets colonized with a probi ...201223142304
identification of a new cell line permissive to porcine reproductive and respiratory syndrome virus infection and replication which is phenotypically distinct from marc-145 cell line.airborne transmitted pathogens, such as porcine reproductive and respiratory syndrome virus (prrsv), need to interact with host cells of the respiratory tract in order to be able to enter and disseminate in the host organism. pulmonary alveolar macrophages (pam) and ma104 derived monkey kidney marc-145 cells are known to be permissive to prrsv infection and replication and are the most studied cells in the literature. more recently, new cell lines developed to study prrsv have been genetically m ...201223148668
increasing expression of microrna 181 inhibits porcine reproductive and respiratory syndrome virus replication and has implications for controlling virus infection.porcine reproductive and respiratory syndrome virus (prrsv) is one of the most important viral pathogens in the swine industry. emerging evidence indicates that the host micrornas (mirnas) are involved in host-pathogen interactions. however, whether host mirnas can target prrsv and be used to inhibit prrsv infection has not been reported. recently, microrna 181 (mir-181) has been identified as a positive regulator of immune response, and here we report that mir-181 can directly impair prrsv infe ...201223152505
cyclophilin inhibitors block arterivirus replication by interfering with viral rna synthesis.virus replication strongly depends on cellular factors, in particular, on host proteins. here we report that the replication of the arteriviruses equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv) is strongly affected by low-micromolar concentrations of cyclosporine a (csa), an inhibitor of members of the cyclophilin (cyp) family. in infected cells, the expression of a green fluorescent protein (gfp) reporter gene inserted into the prrsv genome was inhib ...201223152531
analysis of molecular variation of porcine reproductive and respiratory syndrome virus in central china from 2006 to 2012.to analyze the epidemiology of prrsv in hubei province of china, 668 serum samples collected from 14 pig-breeding farms were tested. we found that the prrsv-positive rate was 5.24 % and that hp-prrsv had become the dominant strain. to further investigate the genetic variation of prrsv strains in this region, the complete gene sequences of nsp2, orf5, and orf7 from nine prrsv strains collected during 2011-2012 were determined and compared with 33 known sequences. the results revealed that diverse ...201323160706
production of antisera against porcine haptoglobin: potential for distinguishing haptoglobin subunits.haptoglobin (hp) is one of the acute phase proteins (apps) that help to alleviate the immune oxidative damage. the present study expressed a truncated porcine hp in escherichia coli and produced rabbit and mouse antisera to the recombinant protein, in order to investigate hp levels in sera from piglets infected with porcine reproduction and respiratory syndrome virus (prrsv). antisera prepared revealed both chains of porcine hp in western blot, and mouse antisera showed stronger binding activiti ...201323164635
complete genome sequence of a highly pathogenic porcine reproductive and respiratory syndrome virus nm1 strain from northern china.nm1 is a highly pathogenic north american-type porcine reproductive and respiratory syndrome virus (prrsv). the complete genome sequence shows that nm1 shares high sequence identity (99.2 to 99.4%) to other hp-prrsv isolates, containing two discontinuous deletions, a 1-amino-acid deletion at position 481 and a 29-amino-acid deletion at positions 533 to 651, in nonstructural protein 2.201223166263
complete genome sequence of porcine reproductive and respiratory syndrome virus strain zcyz isolated from hybrid wild boars.a serologic investigation of porcine reproductive and respiratory syndrome virus (prrsv) in hybrid wild boar herds was conducted during 2008-2009. prrsv isolates with novel genetic markers were recovered. experimental infection of pigs indicated that hybrid wild boars are involved in the epidemiology of prrsv.201223166275
complete genome sequence of a moderately pathogenic porcine reproductive and respiratory syndrome virus variant strain.porcine reproductive and respiratory syndrome (prrs) has become one of the most economically important diseases to the global pork industry. the etiological agent is the prrs virus (prrsv). in the spring of 2006, a highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) appeared in china and caused heavy economic losses. here we report the complete genomic sequence of a novel prrsv variant with 174 amino acid deletions in the nonstructural protein 2 (nsp2) gene.201223166276
porcine reproductive and respiratory syndrome virus, thailand, 2010-2011.characterization of porcine reproductive and respiratory syndrome virus (prrsv) isolates from pigs in thailand showed 30-aa discontinuous deletions in nonstructural protein 2, identical to sequences for highly pathogenic prrsv. the novel virus is genetically related to prrsv from china and may have spread to thailand through illegal transport of infectious animals from bordering countries.201223171619
a pcv2 vaccine based on genotype 2b is more effective than a 2a-based vaccine to protect against pcv2b or combined pcv2a/2b viremia in pigs with concurrent pcv2, prrsv and ppv infection.the predominant genotype of porcine circovirus (pcv) in the pig population today is pcv2b yet pcv2a-based commercial vaccines are considered effective in protecting against porcine circovirus associated disease. the objective of this study was to compare the ability of pcv2a- and pcv2b-based vaccines to control pcv2b viremia in a challenge model that mimics the u.s. field situation. sixty-three pigs were randomly assigned to one of eight groups. sixteen pigs were vaccinated with an experimental ...201323174198
inhibition of porcine reproductive and respiratory syndrome virus replication by flavaspidic acid ab.porcine reproductive and respiratory syndrome virus (prrsv) represents a significant challenge to the swine industry worldwide. current control strategies against prrsv are still inadequate and there is an urgent need for new antiviral therapies. flavaspidic acid ab (fa-ab) is a compound derived from dryopteris crassirhizoma, a traditional antiviral chinese medicine. here, we first identified its anti-prrsv activity through targeting multiple stages in prrsv infection in vitro. our studies demon ...201323178515
sequence analysis of nsp9 gene of 25 prrsv strains from guangdong province, subtropical southern china.in order to evaluate the trend in the prevalence of porcine reproductive and respiratory syndrome on farms, 25 porcine reproductive and respiratory syndrome virus (prrsv) strains were collected from 2009 to 2012 from 11 districts in the guangdong province. the complete gene sequences of nsp9 from the 25 prrsv strains were amplified, sequenced, and then compared with the published sequences of other strains. the results showed that these sequences shared 97.6-99.4 % of the same nucleotides and 97 ...201323180485
detection of vr-2332 strain of porcine reproductive and respiratory syndrome virus type ii using an aptamer-based sandwich-type assay.porcine reproductive and respiratory syndrome virus (prrsv) causes porcine reproductive and respiratory syndrome disease (prrs), a disease that has a significant and economic impact on the swine industry. in this study, single-stranded dna (ssdna) aptamers with high specificity and affinity against vr-2332 strain of prrsv type ii were successfully obtained. of 19 candidates, the lb32 aptamer was found to be the most specific and sensitive to vr-2332 strain according to an aptamer-based surface p ...201323198789
herd-level risk factors for the seropositivity to mycoplasma hyopneumoniae and the occurrence of enzootic pneumonia among fattening pigs in areas of endemic infection and high pig density.the aim of the present study was to identify potential risk factors for the occurrence of enzootic pneumonia (ep) in herds situated in a region of high pig density, where a majority of herds is endemically infected with mycoplasma hyopneumoniae. between 2006 and 2010, overall 100 herds were enrolled in a case-control study. data were collected through personal interview with the farmers, clinical examination of pigs and their environments, and serological testing for m. hyopneumoniae, swine infl ...201423199301
enhanced immunogenicity induced by an alphavirus replicon-based pseudotyped baculovirus vaccine against porcine reproductive and respiratory syndrome virus.pseudotyped baculovirus has emerged as a promising vector for vaccine development and gene therapy. alphaviruses, such as semliki forest virus (sfv), have also received considerable attention for use as expression vectors because of their self-replicating properties. in this study, pseudotyped baculovirus containing the hybrid cytomegalovirus (cmv) promoter/sfv replicon was used as a vector to co-express the gp5 and m proteins of porcine reproductive and respiratory syndrome virus (prrsv). the i ...201323201089
development of a differentiable virus via a spontaneous deletion in the nsp2 region associated with cell adaptation of porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) is renowned for its genetic, antigenic, and pathogenic heterogeneity. as a consequence, highly pathogenic prrsv (hp-prrsv) has emerged and caused tremendous economic losses in the swine industry. in this study, a chinese hp-prrsv jx143 isolate was serially passaged in marc-145 cells up to 100 times. we found that phenotypic changes involved with the cell adaptation process of prrsv jx143 were characterized by higher titers, faster growt ...201323201193
concurrent vaccinations against pcv2 and prrsv: study on the specific immunity and clinical protection in naturally infected pigs.the present study aims at evaluating the efficacy of the concurrent pcv2 and prrs vaccinations in comparison with single vaccinations and placebo in pigs exposed to both natural viral infections. four groups of pigs (200 animals each) at 4 weeks of age were considered. pigs from group a were concurrently vaccinated with a modified live prrsv-1-based vaccine and a genotype a-based pcv2 subunit (cap) vaccine via the intramuscular route. animals from groups b and c were vaccinated with prrsv and pc ...201323206413
reproductive parameters following a prrs outbreak where a whole-herd prrs mlv vaccination strategy was instituted post-outbreak.this study assessed the effect of whole-herd porcine reproductive and respiratory syndrome (prrs) modified-live virus (mlv) vaccination on herd-level reproductive performance, prrs virus (prrsv) viremia, and antibody in a subset of females in a 1,200-sow commercial herd in thailand. following a prrsv outbreak, the entire herd was vaccinated with prrs mlv twice at 3-week intervals and at 3-month intervals, thereafter. reproductive performance data over a 3-year period were available for analysis. ...201323212840
development of indirect elisas for differential serodiagnosis of classical and highly pathogenic porcine reproductive and respiratory syndrome virus.the objective of this study was to develop two indirect enzyme-linked immunosorbent assays (ielisas) for detection of serum antibodies against classical vaccine strain of porcine reproductive and respiratory syndrome virus (prrsv) and highly pathogenic prrsv (hp-prrsv). to detect the common antibodies against classical and hp-prrsv, the coating antigen used in the ielisa (designated ielisa-180) was the antigen of nsp2-180, the 180aa at amino terminal of nsp2. to detect the different antibodies a ...201423217174
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