| immunogenicity of the highly pathogenic porcine reproductive and respiratory syndrome virus gp5 protein encoded by a synthetic orf5 gene. | since may 2006, a highly pathogenic porcine reproductive and respiratory syndrome virus (prrsv), which causes continuous high fever and a high proportion of deaths in vaccinated pigs of all ages, has emerged and prevailed in mainland china. huge efforts should be made towards the development of an efficient vaccine against the highly pathogenic prrsv. although the orf5-encoded gp5 is the most important immunogenic protein, accumulating evidences have demonstrated that incomplete protection confe ... | 2009 | 19368777 |
| evidence of long distance airborne transport of porcine reproductive and respiratory syndrome virus and mycoplasma hyopneumoniae. | the ability of porcine reproductive and respiratory syndrome virus (prrsv) and mycoplasma hyopneumoniae to be transported over long distances via the airborne route was evaluated. a source population of 300 grow-finish pigs was experimentally inoculated with prrsv mn-184 and m. hyopneumoniae 232 and over a 50-day period, air samples were collected at designated distances from the source herd using a liquid cyclonic collector. samples were tested for the presence of prrsv rna and m. hyopneumoniae ... | 2009 | 19379664 |
| identification of snps in porcine genes expressed during porcine respiratory and reproductive syndrome virus infection. | | 2009 | 19392816 |
| application of a protocol for the diagnosis of postweaning multisystemic wasting syndrome in italy. | samples of superficial inguinal and bronchial lymph nodes, ileum, tonsil and lung were taken from three to five pigs on each of 61 farms with a clinical history of postweaning multisystemic wasting syndrome (pmws). the samples were examined histologically and by immunohistochemistry for porcine circovirus type 2 (pcv-2). pmws was diagnosed in two stages: first, an evaluation of the haematoxylin and eosin-stained sections that identified the cases in which the characteristic pcv-2 cytoplasmic inc ... | 2009 | 19395716 |
| serologic survey for selected infectious diseases in raccoons (procyon lotor) in indiana, usa. | the objective of this study was to characterize the antibody prevalence of important livestock and domestic animal pathogens in raccoons (procyon lotor) trapped and sampled in 39 forest patches in north-central indiana, usa, between 2004 and 2005. a total of 459 serum samples were tested for antibodies to leptospira serovars, 512 for canine distemper virus (cdv) antibodies, and 340 for antibodies to porcine reproductive and respiratory syndrome virus (prrsv). in total, 47, 16, and 0% of the samp ... | 2009 | 19395767 |
| rapid detection of porcine reproductive and respiratory syndrome virus by reverse transcription loop-mediated isothermal amplification. | the fragment of the membrane protein m gene with high conservation and specificity of porcine reproductive and respiratory syndrome virus (prrsv) was chosen to be the target region, according to which six special primers were designed successfully. reverse transcription loop-mediated isothermal amplification (rt-lamp) was applied to detect the prrsv by incubation at 65 degrees for only 45 min with the ladder-like pattern of bands from 182 bp on the agarose gel, and the product specificity was co ... | 2009 | 19401617 |
| genetic diversity of the orf5 gene of porcine reproductive and respiratory syndrome virus isolates in china from 2006 to 2008. | since april 2006, swine herds have experienced the outbreaks of a highly pathogenic porcine reproductive and respiratory syndrome (prrs) in china. to explore the possible mechanism of the emergence of the highly pathogenic prrs and more fully understand the extent of genetic diversity of prrsv in china, we analyzed the orf5 gene sequences of 159 representative prrsv isolates in 16 provinces from 2006 to 2008. sequence and phylogenetic analyses showed that all these 159 isolates belonged to the n ... | 2009 | 19406176 |
| reverse transcription loop-mediated isothermal amplification for the detection of porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) is an important pathogen of swine. the objective of the current study is to investigate the feasibility of using reverse transcription loop-mediated isothermal amplification (rt-lamp) for the detection of prrsv. the rt-lamp is a recently described dna amplification technique reported to be simple, inexpensive, fast, and accurate. the rt-lamp reaction was set up using 2 sets of primers that were designed to detect north american and euro ... | 2009 | 19407088 |
| quantitative changes of sialoadhesin and cd163 positive macrophages in the implantation sites and organs of porcine embryos/fetuses during gestation. | porcine reproductive and respiratory syndrome virus (prrsv) crosses the placenta most easily in the last third of gestation. further, prrsv does not replicate in preimplantation embryos but does replicate in postimplantation embryos and fetuses. in the present study, it was aimed to find an explanation for these observations by localization and quantification of the macrophages carrying two entry mediators that play a crucial role in prrsv replication, sialoadhesin (sn) and cd163, in the implant ... | 2009 | 19410291 |
| porcine reproductive and respiratory syndrome virus as a vector: immunogenicity of green fluorescent protein and porcine circovirus type 2 capsid expressed from dedicated subgenomic rnas. | porcine reproductive and respiratory syndrome virus (prrsv) is the causative agent of prrs, which is characterized by late-term abortions in sows and respiratory disease in young pigs. using an infectious cdna clone of north american prrsv strain p129, the viral genome was engineered to transcribe an additional subgenomic rna initiating between non-structural and structural genes. two unique restriction sites and a copy of the transcription regulatory sequence for orf6 (trs6) were inserted betwe ... | 2009 | 19423145 |
| monoclonal antibodies and conserved antigenic epitopes in the c terminus of gp5 protein of the north american type porcine reproductive and respiratory syndrome virus. | glycoprotein 5 (gp5) is the major glycoprotein of porcine reproductive and respiratory syndrome virus (prrsv). in this study, the gene encoding rtgp5, lacking signal peptide sequence, was expressed as gst-fusion protein in e. coli. fifteen monoclonal antibodies (mabs) against rtgp5 were developed and used to probe a series of gp5 peptides by elisa, in which two mabs specifically recognized the epitope gp5ep3 (146-156aa), four recognized gp5ep5 (164-180aa) and nine recognized gp5ep7 (192-200aa). ... | 2009 | 19427138 |
| development and validation of an immunogold chromatographic test for on-farm detection of prrsv. | an immunochromatographic test strip was developed to detect porcine reproductive and respiratory syndrome virus (prrsv). the test uses two gold-labeled monoclonal antibodies: d5 against recombinant nucleocapsid protein (rn) and e9 against recombinant m protein (rm). in the test, prrsv binds to a mixture of d5 and e9 labeled with colloidal gold; the complexes move through a membrane and are captured by rabbit anti-rm and anti-rn antibodies at a test line, producing a reddish-purple band because o ... | 2009 | 19427332 |
| enhanced inhibition of porcine reproductive and respiratory syndrome virus replication by combination of morpholino oligomers. | porcine reproductive and respiratory syndrome (prrs) has caused heavy economic losses in the swine industry worldwide and current strategies to control prrs are inadequate. previous studies have shown that peptide-conjugated phosphorodiamidate morpholino oligomer (ppmo) can be an effective antiviral against the prrs virus (prrsv). ppmo is structurally similar to dna with modified backbone and is resistant to nuclease. this study was designed to examine increasing inhibitory effect of ppmo combin ... | 2009 | 19428596 |
| inhibition of porcine reproductive and respiratory syndrome virus replication by adenovirus-mediated rna interference both in porcine alveolar macrophages and swine. | porcine reproductive and respiratory syndrome virus (prrsv) has been mainly responsible for the heavy economic losses in many swine-producing regions. current vaccination strategies and antiviral drugs provide only limited protection. consequently, there is a need to develop a new antiviral strategy. in this study, two recombinant adenoviruses expressing short-hairpin rnas (shrnas) directed against orf1b of prrsv s1 strain were constructed and the inhibition of prrsv replication was determined. ... | 2009 | 19428607 |
| adenovirus-mediated expression of interferon-alpha delays viral replication and reduces disease signs in swine challenged with porcine reproductive and respiratory syndrome virus. | in this study, pigs were injected with a nonreplicating human adenovirus type 5 vector expressing porcine interferon-alpha (ad5-pifn-alpha) and then challenged with porcine reproductive and respiratory syndrome virus (prrsv) to determine whether the presence of increased levels of ifn-alpha would decrease viral replication and/or disease. groups of 10 pigs each were inoculated with ad5-pifn-alpha and not challenged, ad5-pifn-alpha and challenged with prrsv 1 d later, or inoculated with a control ... | 2009 | 19435413 |
| the effect of vaccination against porcine reproductive and respiratory syndrome virus (prrsv) on the porcine circovirus-2 (pcv-2) load in porcine circovirus associated disease (pcvad) affected pigs. | a diagnostic project was initiated across the united states in 2006 to improve the understanding of porcine circovirus associated diseases (pcvad) as well as to identify co-factors in pcvad-affected farms. a porcine circovirus-2 (pcv-2) dna real-time polymerase chain reaction quantitation (qpcr) was established according to a published method and sera from a total of 23pig farms across the united states were examined for viral loads for pcv-2 and analyzed for any possible effects of porcine repr ... | 2009 | 19436588 |
| further assessment of houseflies (musca domestica) as vectors for the mechanical transport and transmission of porcine reproductive and respiratory syndrome virus under field conditions. | the purpose of this study was to evaluate the potential for houseflies (musca domestica) to mechanically transport and transmit porcine reproductive and respiratory syndrome virus (prrsv) between pig populations under controlled field conditions. the study employed swine housed in commercial livestock facilities and a release-recapture protocol involving marked (ochre-eyed) houseflies. to assess whether transport of prrsv by insects occurred, ochre-eyed houseflies were released and collected fro ... | 2009 | 19436589 |
| efficacy of a modified live porcine reproductive and respiratory syndrome virus (prrsv) vaccine in pigs naturally exposed to a heterologous european (italian cluster) field strain: clinical protection and cell-mediated immunity. | the purpose of this study was to assess clinical protection in pigs vaccinated with a commercially available attenuated porcine reproductive and respiratory syndrome virus (prrsv) vaccine (porcilis) prrs) and then naturally exposed under field conditions to a heterologous (italian cluster) strain of virulent prrsv. a total of 30, 4-week-old pigs seronegative for prrsv were allocated to 1 of 3 groups (im, id, and c groups). at 5 weeks of age, pigs of groups im (n=10 pigs) and id (n=10 pigs) were ... | 2009 | 19442420 |
| functional impairment of prrsv-specific peripheral cd3+cd8high cells. | the replication of porcine reproductive and respiratory syndrome virus (prrsv) in lungs and lymphoid tissues of prrsv-infected pigs is already strongly reduced before the appearance of neutralizing antibodies, indicating that other immune mechanisms are involved in eliminating prrsv at those sites. this study aimed to determine whether prrsv lelystad virus (lv)-specific cytotoxic t-lymphocytes (ctl) can efficiently eliminate prrsv-infected alveolar macrophages. therefore, ctl assays were perform ... | 2009 | 19445889 |
| genetic analysis of orf5 of recent korean porcine reproductive and respiratory syndrome viruses (prrsvs) in viremic sera collected from mlv-vaccinating or non-vaccinating farms. | the 23 open reading frame (orf) 5 sequences of korean type ii porcine reproductive and respiratory syndrome virus (prrsv) were collected from viremic sera from the (modified live vaccine) mlv-vaccinating and non-vaccinating farms from 2007 to 2008. the samples were phylogenetically analyzed with previous orf5 sequences, including type i korean prrsv, and previously reported or collected sequences from 1997 to 2008. a mn184-like subgroup of type ii korean prrsv was newly identified in the viremic ... | 2009 | 19461207 |
| gm-csf fused with gp3 and gp5 of porcine reproductive and respiratory syndrome virus increased the immune responses and protective efficacy against virulent prrsv challenge. | porcine reproductive and respiratory syndrome virus (prrsv) has recently caused catastrophic losses in swine industry worldwide. current vaccination strategies only provide a limited protection against prrsv infection. this study was aimed to construct the recombinant adenovirus co-expressing gp3 and gp5 of highly pathogenic prrsv fused with swine granulocyte-macrophage colony stimulating factor (gm-csf) (rad-gf35), and to detect the immune response in mice and pigs. the results showed that the ... | 2009 | 19463718 |
| challenges for porcine reproductive and respiratory syndrome virus (prrsv) vaccinology. | porcine reproductive and respiratory syndrome virus (prrsv) continues to be a threat for the pig industry. vaccines have been developed, but these failed to provide sustainable disease control, in particular against genetically unrelated strains. here we give an overview of current knowledge and gaps in our knowledge that may be relevant for the development of a future generation of more effective vaccines. prrsv replicates in cells of the monocyte/macrophage lineage, induces apoptosis and necro ... | 2009 | 19464553 |
| development of a vaccine vector based on a subgenomic replicon of porcine reproductive and respiratory syndrome virus. | in this study, a dna-launched subgenomic replicon of porcine reproductive and respiratory syndrome virus (prrsv) was developed for use as a vaccine vector. this replicon plasmid contained a prrsv subgenome without structural genes orf2-orf6, and was under the transcriptional control of the immediate-early promoter of cytomegalovirus (cmv). using enhanced green fluorescent protein (egfp) as a reporter gene, the dna-launched subgenomic replicon of prrsv, named pok-clone20-rep, could express hetero ... | 2009 | 19464739 |
| multiplex pcr and multiplex rt-pcr for inclusive detection of major swine dna and rna viruses in pigs with multiple infections. | multiplex pcr and multiplex rt-pcr were developed to identify nine viruses in pigs with multiple infections. these viruses are: porcine circovirus type 2 (pcv2), suid herpesvirus 1, porcine parvovirus (ppv), porcine reproductive and respiratory syndrome virus (prrsv), japanese encephalitis virus, porcine rotavirus a (porv-a), porcine epidemic diarrhea virus (pedv), transmissible gastroenteritis virus (tgev), and getah virus. these methods were shown to be high specificity and sensitivity. in the ... | 2009 | 19467264 |
| gp3 is a structural component of the prrsv type ii (us) virion. | glycoprotein 3 (gp3) is a highly glycosylated prrsv envelope protein which has been reported as being present in the virions of prrsv type i, while missing in the type ii prrsv (us) virions. we herein present evidence that gp3 is indeed incorporated in the virus particles of a north american strain of prrsv (fl12), at a density that is consistent with the minor structural role assigned to gp3 in members of the arterivirus genus. two 15aa peptides corresponding to two different immunodominant lin ... | 2009 | 19467555 |
| function of prrsv gp5 envelope protein by using pseudotyped virus. | the porcine reproductive and respiratory syndrome virus (prrsv) is an enveloped rna virus. virions of prrsv contain six membrane proteins: the major proteins gp5 and m and the minor proteins gp2, gp3, gp4, and e. the gp5 is the major envelope proteins, which was involved in the formation and infectivity of prrsv by coaction with other membrane proteins. here, to determine the function of alone gp5 envelope protein in viral entry, we investigated the formation and infectivity of gp5-pseudotyped v ... | 2009 | 19477088 |
| qtl for traits related to humoral immune response estimated from data of a porcine f2 resource population. | this study aimed to map quantitative trait loci (qtl) for traits related to humoral innate immune defence. therefore, haemolytic complement activity in the alternative and the classical pathway, serum concentration of c3c and of haptoglobin (hp) were measured in blood samples obtained from f2 piglets (n = 457) of a porcine f2 resource population before and after mycoplasma hyopneumoniae, aujeszky's disease virus (suid herpesvirus i, suhvi) and porcine reproductive and respiratory syndrome virus ... | 2009 | 19490209 |
| constitutive expression of interferons in swine leukocytes. | interferon (ifn)-alpha and ifn-gamma positive cells were revealed by flow cytometry in peripheral blood mononuclear cells (pbmc) of specific pathogen free (spf) pigs. a low prevalence of ifn-gamma positive cells was also detected in pbmc of some porcine reproductive and respiratory syndrome virus-infected pigs and uninfected, control pigs. ifn-alpha positive cells showed phenotypes of both monocytes and plasmacytoid dendritic cells. the presence of ifn-alpha in pbmc was also confirmed by western ... | 2010 | 19497601 |
| identification and characterization of a porcine monocytic cell line supporting porcine reproductive and respiratory syndrome virus (prrsv) replication and progeny virion production by using an improved dna-launched prrsv reverse genetics system. | in this study, an improved dna-launched (plasmid dna transfection-based) reverse genetics system with reduced cost and labor was developed for porcine reproductive and respiratory syndrome virus (prrsv) by introduction of ribozyme elements at both termini of the viral genomic cdna that were placed under the control of a eukaryotic hybrid promoter. the rescue efficacy of prrsv with this system was approximately 10-50-fold higher than the in vitro-transcribed rna-based system and the traditional d ... | 2009 | 19505514 |
| the lactate dehydrogenase-elevating virus capsid protein is a nuclear-cytoplasmic protein. | arteriviruses replicate in the cytoplasm and do not require the nucleus function for virus multiplication in vitro. however, nucleocapsid (n) protein of two arteriviruses, porcine reproductive respiratory syndrome virus and equine arteritis virus, has been observed to localize in the nucleus and nucleolus of virus-infected and n-gene-transfected cells in addition to their normal cytoplasmic distribution. in the present study, the n protein of lactate dehydrogenase-elevating virus (ldv) of mice w ... | 2009 | 19517211 |
| probability of freedom from disease after the first detection and eradication of prrs in sweden: scenario-tree modelling of the surveillance system. | in july 2007, prrs was detected for the first time in sweden. a total of eight positive herds were identified and various measures were taken to eradicate the disease, including restrictions and slaughter of infected herds. subsequently, both active and passive surveillance activities were undertaken. this study describes stochastic scenario-tree modelling of all the various surveillance system components, to estimate the current probability that sweden is free from prrs. the model includes all ... | 2009 | 19520445 |
| risk factors associated with pleuritis and cranio-ventral pulmonary consolidation in slaughter-aged pigs. | examination of lung lesions at the slaughterhouse is a useful tool to estimate the importance of respiratory disease at farm, regional or national level. the objective of the present work was to describe the prevalence of gross lung lesions at slaughter, with a special focus on pleuritis and cranio-ventral pulmonary consolidation, and to identify major risk factors for these lesions. data from 107 farms involving approximately 11,000 pigs enabled gross lung lesions to be correlated with serology ... | 2010 | 19527939 |
| rapid differential detection of classical and highly pathogenic north american porcine reproductive and respiratory syndrome virus in china by a duplex real-time rt-pcr. | since the emergence of highly pathogenic north american porcine reproductive and respiratory syndrome virus (h-us-prrsv) in 2006, the classical north american prrsv (c-us-prrsv) and h-us-prrsv isolates have coexisted in chinese swine herds. a duplex real-time rt-pcr assay using minor groove binder (mgb) probes for differential detection of the two us prrsv isolates was developed. the specificity, sensitivity, reproducibility, and interference test of this assay were validated. the sensitivity of ... | 2009 | 19539654 |
| infection of porcine alveolar macrophages with recombinant chimeric porcine reproductive and respiratory syndrome virus: effects on cellular gene transcription and virus growth. | porcine reproductive and respiratory syndrome virus (prrsv) genetic determinants affecting the response of the host primary target cell, the macrophage, to infection are yet to be defined. here we have used recombinant viruses encompassing orf 1a to identify prrsv determinants associated with growth and modulation of pro- and anti-inflammatory cytokine expression in primary pulmonary alveolar macrophages (pams) cultures. three genomic chimeras encompassing orf 1a of prrsv live attenuated vaccine ... | 2009 | 19540286 |
| secretory expression of porcine interferon-gamma in baculovirus using hbm signal peptide and its inhibition activity on the replication of porcine reproductive and respiratory syndrome virus. | the gene sequence encoding mature porcine interferon-gamma (poifn-gamma) fused with a c-terminal 6x histidine tag was cloned into the baculovirus pfastbac dual vector of the bac-to-bac baculovirus expression system under the control of ph promoter. the authentic signal sequence of porcine interferon-gamma was substituted with the honeybee melittin (hbm) signal sequence, and expressed in insect cells. the recombinant proteins were detected by sds-page and immunofluorescence assay. the nickel affi ... | 2009 | 19556014 |
| molecular variation analysis of porcine reproductive and respiratory syndrome virus in china. | porcine reproductive and respiratory syndrome virus (prrsv) is characteristic of genetically extensive variation. the objective of the present study was to analyze the molecular variation and evolution of porcine reproductive and respiratory syndrome virus in china based on the complete genomic sequences of three highly pathogenic chinese prrsv strains isolated in 2006 and the sequences of the amplified nsp2, orf5 and orf7 genes from clinical specimens during 2006-2008. full-length genome sequen ... | 2009 | 19559739 |
| genotyping of haemophilus parasuis from diseased pigs in china and prevalence of two coexisting virus pathogens. | from december 2003 to july 2006, a total of 131 (28.4%) haemophilus parasuis strains were isolated from 462 cases examined in our diagnostic laboratory. these strains were isolated from clinically diseased pigs, and 50 of them along with 15 reference strains of all known serovars were subjected to pcr-frlp (restriction fragment length polymorphism) analysis by tbpa gene. the analysis of the 1.9-kb tbpa amplicon using taqi, avai and rsai endonucleases produced 9 rflp patterns for the 15 reference ... | 2009 | 19586670 |
| the porcine reproductive and respiratory syndrome virus nsp2 cysteine protease domain possesses both trans- and cis-cleavage activities. | the n terminus of the replicase nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (prrsv) contains a putative cysteine protease domain (pl2). previously, we demonstrated that deletion of either the pl2 core domain (amino acids [aa] 47 to 180) or the immediate downstream region (aa 181 to 323) is lethal to the virus. in this study, the pl2 domain was found to encode an active enzyme that mediates efficient processing of nsp2-3 in cho cells. the pl2 protease pos ... | 2009 | 19587037 |
| discovery of swine as a host for the reston ebolavirus. | since the discovery of the marburg and ebola species of filovirus, seemingly random, sporadic fatal outbreaks of disease in humans and nonhuman primates have given impetus to identification of host tropisms and potential reservoirs. domestic swine in the philippines, experiencing unusually severe outbreaks of porcine reproductive and respiratory disease syndrome, have now been discovered to host reston ebolavirus (rebov). although rebov is the only member of filoviridae that has not been associa ... | 2009 | 19590002 |
| antimicrobial host defense peptides in an arteriviral infection: differential peptide expression and virus inactivation. | antimicrobial host defense peptides (ahdps) are effective against a wide range of microbes, including viruses. the arteriviral infection caused by porcine reproductive and respiratory syndrome virus (prrsv) is a devastating pandemic that causes the most economically significant disease of swine. we sought to determine if the expression of ahdps was influenced by infection with prrsv, and if porcine ahdps have direct antiviral activity against prrsv. because pulmonary alveolar macrophages (pams) ... | 2009 | 19594394 |
| changes in lymphocyte subsets and cytokines during european porcine reproductive and respiratory syndrome: increased expression of il-12 and il-10 and proliferation of cd4(-)cd8(high). | the changes in peripheral blood mononuclear cells (pbmcs) have been studied in several reports in an attempt to determine the immune response against porcine reproductive and respiratory syndrome virus (prrsv) infection. however, how these changes are evoked after prrsv infection has not yet been clarified. the aim of this study was to analyze the changes seen in lymphocyte subsets and immunomodulatory cytokine expression in pigs after an acute experimental infection with a european prrsv field ... | 2009 | 19594397 |
| vaccine efficacy and immune response to swine influenza virus challenge in pigs infected with porcine reproductive and respiratory syndrome virus at the time of siv vaccination. | the objective of this study was to assess the effect of concurrent infection with porcine reproductive and respiratory syndrome virus (prrsv) on the efficacy of an inactivated swine influenza virus (siv) vaccine. eight groups of pigs were infected with a virulent prrsv isolate either between the two siv vaccines or at the time of siv challenge. control groups included siv vaccination without prrsv and pigs infected with siv and/or prrsv. pigs infected with prrsv during vaccination showed increas ... | 2009 | 19595522 |
| soy isoflavones and virus infections. | isoflavones and their related flavonoid compounds exert antiviral properties in vitro and in vivo against a wide range of viruses. genistein is, by far, the most studied soy isoflavone in this regard, and it has been shown to inhibit the infectivity of enveloped or nonenveloped viruses, as well as single-stranded or double-stranded rna or dna viruses. at concentrations ranging from physiological to supraphysiological (3.7-370 mum), flavonoids, including genistein, have been shown to reduce the i ... | 2009 | 19596314 |
| pathogen exposure in feral swine populations geographically associated with high densities of transitional swine premises and commercial swine production. | surveys for evidence of exposure to pseudorabies virus (prv), brucella suis, swine influenza virus (siv; human-like h1n1, reassortant type h1n1, h1n2-like h1n1 and h3n2), porcine circovirus 2 (pcv 2), and porcine respiratory and reproductive syndrome virus (prrsv) in feral swine (sus scrofa) were conducted in areas where feral swine were geographically associated with high densities of transitional swine premises in south carolina and high densities of commercial swine production in north caroli ... | 2009 | 19617481 |
| immunohistochemical detection of aetiological agents of proliferative and necrotizing pneumonia in italian pigs. | proliferative and necrotizing pneumonia (pnp) is a form of interstitial pneumonia that occurs in weaning and post-weaning pigs. pnp is characterized by hypertrophy and hyperplasia of type ii pneumocytes and coagulative necrosis and granular debris within alveolar spaces. canadian and european studies suggest that the porcine reproductive and respiratory syndrome virus (prrsv) and porcine circovirus type 2 (pcv2) are the main causes of the disease, but aujezsky's disease virus (adv) and swine inf ... | 2010 | 19631945 |
| [construction and immunogenicity of recombinant adenovirus co-expressing the gp5 and m protein of porcine reproduction and respriratory syndrome virus in mice]. | fmdv 2a peptide was introduced as a linker between gp5 and m protein of porcine reproduction and respiratory syndrome virus (prrsv) to allow automatic self-cleavage the polyproteins. this strategy simultaneously displayed the neutralizing action of gp5 protein and cell-mediated immunity of m protein. we put them into the expression cassette of adenovirus vector. the results of rt-pcr, ifa and western blotting showed that gp5 and m protein were not only expressed correctly, but also self-cleavage ... | 2009 | 19637620 |
| in silico prediction and ex vivo evaluation of potential t-cell epitopes in glycoproteins 4 and 5 and nucleocapsid protein of genotype-i (european) of porcine reproductive and respiratory syndrome virus. | t-cell epitopes of porcine reproductive and respiratory syndrome virus (prrsv) glycoproteins 4 (gp4), 5 (gp5) and nucleocapsid (n) were predicted using bioinformatics and later tested by ifn-gamma elispot in pigs immunized with either a modified live vaccine (mlv) or dna (open reading frames 4, 5 or 7). for mlv-vaccinated pigs, immunodominant epitopes were found in n but t-epitopes were also found in gp4 and gp5. for dna-immunized pigs, some peptides were differently recognized. using a large se ... | 2009 | 19646408 |
| structure and cleavage specificity of the chymotrypsin-like serine protease (3clsp/nsp4) of porcine reproductive and respiratory syndrome virus (prrsv). | biogenesis and replication of the porcine reproductive and respiratory syndrome virus (prrsv) include the crucial step of replicative polyprotein processing by self-encoded proteases. whole genome bioinformatics analysis suggests that nonstructural protein 4 (nsp4) is a 3c-like serine protease (3clsp), responsible for most of the nonstructural protein processing. the gene encoding this protease was cloned and expressed in escherichia coli in order to confirm this prediction. the purified protein ... | 2009 | 19646449 |
| porcine reproductive and respiratory syndrome virus modifies innate immunity and alters disease outcome in pigs subsequently infected with porcine respiratory coronavirus: implications for respiratory viral co-infections. | the innate immune response is critical for host defence against respiratory coronaviruses (covs). this study demonstrated that an ongoing respiratory virus infection compromises innate immune responses and affects the pathogenesis of a respiratory cov co-infection. an innate immunosuppressive respiratory virus infection was established by infecting weaned pigs with porcine reproductive and respiratory syndrome virus (prrsv); 10 days later, the pigs were exposed to porcine respiratory coronavirus ... | 2009 | 19656969 |
| genetic variation and pathogenicity of highly virulent porcine reproductive and respiratory syndrome virus emerging in china. | a highly pathogenic swine disease designated as 'porcine high fever disease (phfd)' appeared recently in china. porcine reproductive and respiratory syndrome virus (prrsv) was identified as an agent associated with phfd, and two discontiguous sequence deletions were identified as a genetic marker in the nsp2 region of the viral genome. to examine phfd in shandong province, a total of 10 prrsv isolates were recovered from pig herds that had never been vaccinated for prrs. sequence analysis of ope ... | 2009 | 19672556 |
| [effects of fusion gene of ubiquitin and porcine reproductive and respiratory syndrome virus m gene on the immune response in inoculated mice]. | to evaluate the effects of the fusion gene of ubiquitin (ub) and porcine reproductive and respiratory syndrome virus (prrsv) m gene on the immune response in inoculated mice. | 2009 | 19673417 |
| assessing the functionality of viral entry-associated domains of porcine reproductive and respiratory syndrome virus during inactivation procedures, a potential tool to optimize inactivated vaccines. | porcine reproductive and respiratory syndrome virus (prrsv) causes severe economic losses in the pig industry worldwide. currently, vaccines based on inactivated prrsv provide limited protection of pigs against infection, most likely because viral epitopes associated with the induction of neutralizing antibodies are not or poorly conserved during inactivation. to analyze the effect of inactivation procedures on the interaction of prrsv with receptors involved in virus entry, a new assay was set ... | 2009 | 19674538 |
| development of an experimental inactivated prrsv vaccine that induces virus-neutralizing antibodies. | porcine reproductive and respiratory syndrome virus (prrsv) can induce reproductive disorders and is involved in the porcine respiratory disease complex, causing tremendous economic losses to the swine industry. inactivated prrsv vaccines are preferred over attenuated vaccines because of their safety and flexibility towards emerging virus strains, but the efficacy of current inactivated prrsv vaccines is questionable. in this study, experimental inactivated prrsv vaccines were developed, based o ... | 2009 | 19674539 |
| avian influenza virus, streptococcus suis serotype 2, severe acute respiratory syndrome-coronavirus and beyond: molecular epidemiology, ecology and the situation in china. | the outbreak and spread of severe acute respiratory syndrome-associated coronavirus and the subsequent identification of its animal origin study have heightened the world's awareness of animal-borne or zoonotic pathogens. in addition to sars, the highly pathogenic avian influenza virus (aiv), h5n1, and the lower pathogenicity h9n2 aiv have expanded their host ranges to infect human beings and other mammalian species as well as birds. even the 'well-known' reservoir animals for influenza virus, m ... | 2009 | 19687041 |
| cytokine expression by macrophages in the lung of pigs infected with the porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome (prrs) is caused by a virus that predominantly replicates in alveolar macrophages. the aim of the present study was to characterize the production of cytokines by subpopulations of pulmonary macrophages in pigs infected by the prrs virus (prrsv). expression of interleukin (il) 1alpha, il-6 and tumour necrosis factor (tnf)-alpha correlated with the severity of pulmonary pathology and the numbers of pulmonary macrophages. significant correlations were ... | 2010 | 19691969 |
| frequency of prrs live vaccine virus (european and north american genotype) in vaccinated and non-vaccinated pigs submitted for respiratory tract diagnostics in north-western germany. | the frequency of prrsv corresponding to live vaccines and wild-type was determined in 902 pigs from north-western germany submitted for post-mortem examination. overall, 18.5% of the samples were positive for the eu wild-type virus. eu genotype vaccine virus was detected in 1.3% and the na genotype vaccine virus in 8.9% of all samples. the detection of the eu vaccine was significantly higher in pigs vaccinated with the corresponding vaccine (or=9.4). pigs vaccinated with na genotype had signific ... | 2009 | 19700211 |
| crystal structure of porcine reproductive and respiratory syndrome virus leader protease nsp1alpha. | porcine reproductive and respiratory syndrome (prrs) virus (prrsv), a positive-strand rna virus that belongs to the arteriviridae family of nidovirales, has been identified as the causative agent of prrs. nsp1alpha is the amino (n)-terminal protein in a polyprotein encoded by the prrsv genome and is reported to be crucial for subgenomic mrna synthesis, presumably by serving as a transcription factor. before functioning in transcription, nsp1alpha proteolytically releases itself from nsp1beta. ho ... | 2009 | 19706710 |
| induction of inducible cd4+cd25+foxp3+ regulatory t lymphocytes by porcine reproductive and respiratory syndrome virus (prrsv). | increases in numbers or activities of regulatory t lymphocytes (tregs) have been linked to the establishments of several persistent infections. it has been previously shown that porcine reproductive and respiratory syndrome virus (prrsv) can negatively modulate the host immune responses, resulting in persistent infection and secondary immunodeficiency. recently, the existence of porcine cd4(+)cd25(+) tregs has been demonstrated. we investigated the effect of prrsv on the cd4(+)cd25(+) tregs. the ... | 2010 | 19709757 |
| cloning, in vitro expression, and bioactivity of interleukin-18 isolated from a domestic porcine breed found in henan. | to evaluate the effects of recombinant porcine interleukin-18 (rpil-18) on the replication of viruses in host cells and proliferation of lymphocytes, porcine il-18 (pil-18) isolated from a domestic big-white porcine breed found in the henan province (hn) was cloned using a reverse transcriptase-pcr. the cloned hn pil-18 contained an orf of 579 base pairs encoding a 192-amino-acid precursor protein. the amino acid sequence of hn pil-18 was compared with all the other pil-18 amino acid sequences a ... | 2009 | 19732142 |
| antigen-capture blocking enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen to differentiate transmissible gastroenteritis virus from porcine respiratory coronavirus antibodies. | a new commercially available antigen-capture, blocking enzyme-linked immunosorbent assay (antigen-capture b-elisa), based on baculovirus truncated-s recombinant protein of transmissible gastroenteritis virus (tgev) and 3 specific monoclonal antibodies, was developed and evaluated by examining a panel of 453 positive porcine respiratory coronavirus (prcov), 31 positive tgev, and 126 negative field sera by using another commercially available differential coronavirus b-elisa as the reference techn ... | 2009 | 19737754 |
| efficacy of porcine reproductive and respiratory syndrome virus vaccine and porcine interleukin-12. | the efficacy of porcine recombinant interleukin-12 (pril-12) as an adjuvant to stimulate immunity was investigated in pigs vaccinated against porcine reproductive and respiratory syndrome virus (prrsv). porcine recombinant il-12 was cloned and expressed in the insect baculovirus system. thirty pigs were randomly allocated to five groups, and individual pigs were injected with prrsv modified live virus with and without coadministration of pril2; prrsv killed virus with and without coadministratio ... | 2001 | 19753703 |
| comparative analysis of complete nucleotide sequence of porcine reproductive and respiratory syndrome virus (prrsv) isolates in thailand (us and eu genotypes). | porcine reproductive and respiratory syndrome virus (prrsv) is a causative agent of porcine reproductive and respiratory syndrome (prrs). in this study, the complete nucleotide sequences of the selected two thai prrsv isolates, eu (01cb1) and us (01np1) genotypes were determined since both isolates are the thai prototypes. | 2009 | 19754975 |
| localization of porcine reproductive and respiratory syndrome virus in mammary glands of experimentally infected sows. | we investigated the localization of porcine reproductive and respiratory syndrome virus (prrsv) in the mammary glands of experimentally infected sows using reverse transcription pcr and immunohistochemistry. six pregnant sows were inoculated intranasally with prrsv three weeks prior to the predicted farrowing date. the six prrsv-infected sows and two uninfected negative control sows remained clinically healthy and farrowed normally. milk samples were collected from all sows on lactation days 1, ... | 2010 | 19767042 |
| [comparison of antiviral activities of porcine interferon type i and type ii]. | interferons (ifns) are natural proteins produced by wide variety of cells in response to viral infection or other biological inducers, and they execute diversified functions as antiviral defense, immune activation and cell growth regulation. four genes encoding porcine interferons (poifn), poifn-alpha, poifn-gamma, poifn-alphagamma or polfn-omega, were cloned and sequenced. the four types of porcine interferon genes were subcloned into the pet-his vector, and expressed in escherichia coli rosett ... | 2009 | 19777805 |
| porcine circovirus type 2 and porcine circovirus-associated disease. | porcine circovirus type 2 (pcv2) belongs to the viral family circoviridae and to the genus circovirus. circoviruses are small, single-stranded nonenveloped dna viruses that have an unsegmented circular genome. pcv2 is the primary causative agent of several syndromes collectively known as porcine circovirus-associated disease (pcvad). many of the syndromes associated with pcvad are a result of coinfection with pcv2 virus and other agents such as mycoplasma and porcine reproductive and respiratory ... | 2009 | 19780932 |
| comparative infection efficiency of porcine reproductive and respiratory syndrome virus field isolates on ma104 cells and porcine alveolar macrophages. | isolation of porcine reproductive and respiratory syndrome virus (prrsv) on ma104 or marc-145 cells is frequently used in prrs diagnosis. however, the ability of recent field isolates to grow on these established simian cell lines has not been determined. the aim of this study was to characterize the growth of prrsv field isolates on primary porcine alveolar macrophages (pams) and ma104 cells in comparison with the growth of the laboratory-adapted strain vr-2332. a cytopathic effect was observed ... | 2009 | 19794892 |
| detection of asymptomatic antigenemia in pigs infected by porcine reproductive and respiratory syndrome virus (prrsv) by a novel capture immunoassay with monoclonal antibodies against the nucleocapsid protein of prrsv. | routine surveillance for porcine reproductive and respiratory syndrome virus (prrsv) infections is crucial for the epidemiological control of this disease. antibody tests are widely used but cannot differentiate between vaccination and reinfection. we developed a prrsv antigen capture enzyme-linked immunosorbent assay (elisa) using well-characterized monoclonal antibodies (mabs) raised against the nucleocapsid (n) protein of north american and european prrsv. this antigen assay detected purified ... | 2009 | 19828768 |
| development and validation of a recombinant nucleocapsid protein-based elisa for detection of the antibody to porcine reproductive and respiratory syndrome virus. | three indirect enzyme-linked immunosorbent assays (ielisa) based on the north american like (na-like), european like (eu-like) and co-expressed na- and eu-like recombinant nucleocapsid proteins (n-protein) of porcine reproductive and respiratory syndrome virus (prrsv) were validated for the detection of the antibodies in porcine sera. a total of 422 serum samples from unvaccinated pigs were tested. the cut-off value was optimized by a two-graph receiver operating characteristics analysis at a 95 ... | 2009 | 19851731 |
| cytokine mrna expression profiles in peripheral blood mononuclear cells from piglets experimentally co-infected with porcine reproductive and respiratory syndrome virus and porcine circovirus type 2. | porcine reproductive and respiratory syndrome virus (prrsv) and porcine circovirus type 2 (pcv2) significantly impact the swine industry worldwide. co-infections with these viruses are common and several lines of evidence suggest that both prrsv and pcv2 modify host immune responses that facilitate infection. this study examined cytokine mrna expression profiles of peripheral blood mononuclear cells (pbmcs) from piglets experimentally co-infected with prrsv and pcv2 to define the influence of co ... | 2010 | 19854008 |
| porcine ulcerative dermatitis syndrome in sows: a form of vesicular cutaneous lupus erythematosus? | severe ulcerative lesions were observed in the skin of two sows in a herd of 540 hybrid sows. annular to polycyclic, severe crusting dermal ulcerations were found on the abdomen and flanks; moderate lesions were also found at the base of the tail and on the perineum. the lesions were histologically characterised as cell-poor interface dermatitis and folliculitis, basal cell vacuolisation, vesicle formation at the dermal-epidermal junction and serocellular crusts. a subepidermal mild to moderate ... | 2009 | 19855113 |
| age-dependent resistance to porcine reproductive and respiratory syndrome virus replication in swine. | porcine reproductive and respiratory syndrome virus (prrsv) causes a prolonged, economically devastating infection in pigs, and immune resistance to infection appears variable. since the porcine adaptive immune system is not fully competent at birth, we hypothesized that age influences the dynamics of prrsv infection. thus, young piglets, growing 16-20-week-old finisher pigs, and mature third parity sows were infected with virulent or attenuated prrsv, and the dynamics of viral infection, diseas ... | 2009 | 19860914 |
| compatibility of a combined vaccination against haemophilus parasuis and porcine reproductive and respiratory syndrome virus. | objective of this study was to assess the tissue compatibility of a vaccination, combining vaccines against haemophilus parasuis and porcine reproductive and respiratory syndrome virus (prrsv). clinical examinations were done with special respect to local tissue reactions after injection of 2 ml each of either porcilis glasser, or porcilis prrs (both intervet, unterschleissheim, germany), or a mixture of the two vaccines. animals were euthanized on day six post vaccination. clinical as well as g ... | 2009 | 19863006 |
| the porcine reproductive and respiratory syndrome virus requires trafficking through cd163-positive early endosomes, but not late endosomes, for productive infection. | the porcine reproductive and respiratory syndrome virus (prrsv) enters its target cell via clathrin-mediated endocytosis. using dominant-negative rab5 and rab7 mutants, we show that upon internalization, prrsv enters early endosomes but does not continue through the endocytic pathway to late endosomes. this was confirmed via colocalization experiments visualizing prrsv and markers for different compartments of the endocytic pathway. furthermore, it was shown that prrsv colocalizes with its inter ... | 2009 | 19885719 |
| generation of a porcine alveolar macrophage cell line for the growth of porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) has a marked tropism for cells of the monocyte-macrophage lineage and accordingly, replicates in fully differentiated alveolar macrophages in the natural host. despite the identification of several putative receptors for prrsv on porcine alveolar macrophages (pam), only cd163 was found to be able to make non-permissive cells susceptible to prrsv, indicating a requirement for cd163 in productive infection. interestingly, the preliminary ... | 2010 | 19900480 |
| development and validation of reverse transcription loop-mediated isothermal amplification for detection of prrsv. | to establish a reverse-transcription loop-mediated isothermal amplification (rt-lamp) method for rapid detection of porcine reproductive and respiratory syndrome virus (prrsv), four primers specific to six regions of the n gene were designed. after amplification in an isothermal water bath for 1 h, samples containing prrsv generated the expected ladder-like products while porcine parvovirus, porcine circovirus, classic swine fever virus, pseudorabies virus, and swine testis cells generated no pr ... | 2010 | 19911264 |
| european genotype of porcine reproductive and respiratory syndrome (prrsv) infects monocyte-derived dendritic cells but does not induce treg cells. | the aim of this study was to characterize the immune responses of dcs after infection with four different eu strains of prrsv and whether they show any ability to immunomodulate t cells activation. our results show that all eu strains can efficiently infect and replicate in dcs. nevertheless, sla-ii levels remained unaltered in dc infected by all eu prrsv strains, whereas sla-i expression was only reduced when strain 2992 was used. il-10 production was induced by three eu prrsv strains, being st ... | 2010 | 19913865 |
| morpholino oligomer-mediated protection of porcine pulmonary alveolar macrophages from arterivirus-induced cell death. | porcine reproductive and respiratory syndrome (prrs) causes extensive economic losses in the swine industry. current strategies and vaccines to control the disease are inadequate. we previously demonstrated that peptide-conjugated phosphorodiamidate morpholino oligomers (ppmos) could potently inhibit prrs virus (prrsv) replication in cell cultures. ppmos are single-stranded dna analogues containing a modified backbone and cell-penetrating peptide. ppmos are nuclease-resistant, water-soluble, can ... | 2009 | 19918094 |
| porcine reproductive and respiratory syndrome virus nonstructural protein 1beta modulates host innate immune response by antagonizing irf3 activation. | porcine reproductive and respiratory syndrome virus (prrsv) infection of swine leads to a serious disease characterized by a delayed and defective adaptive immune response. it is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. in the study presented here we tested this hypothesis and identified several nonstructural proteins (nsps) with innate immune evasion properties encoded by the prrs viral genome. four of the total ten prrsv nsps tested wer ... | 2010 | 19923190 |
| immunodominant epitopes in nsp2 of porcine reproductive and respiratory syndrome virus are dispensable for replication, but play an important role in modulation of the host immune response. | non-structural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (prrsv) is the largest protein of this virus. in addition to its crucial role in virus replication, recent studies have indicated its involvement in modulating host immunity. in this study, each of the six identified immunodominant nsp2 b-cell epitopes (es2-es7) was deleted using a type i prrsv cdna infectious clone. deletion of es3, es4 or es7 allowed the generation of viable virus. in comparison with the par ... | 2010 | 19923257 |
| development and evaluation of rapid detection of classical swine fever virus by reverse transcription loop-mediated isothermal amplification (rt-lamp). | a one-step reverse transcription loop-mediated isothermal amplification (rt-lamp) was developed for the detection of classical swine fever virus (csfv) and a set of primers designed based on the e2 gene reference sequences of the csfv. the assay was optimized to amplify csfv rna by incubation at 63 degrees c for 50 min. the rt-lamp amplification products had a ladder-like appearance when electrophoresed on an agarose gel. the rt-lamp assay showed higher sensitivity than the conventional rt-pcr, ... | 2010 | 19931578 |
| phylogenetic characterization of genes encoding for glycoprotein 5 and membrane protein of prrsv isolate hh08. | a porcine reproductive and respiratory syndrome virus (prrsv) was obtained from clinic samples. genes 5 and 6 encoding for the viral glycoprotein 5 and a membrane protein of the prrsv designated as hh08 were amplified by reverse transcription-pcr. these sequences were compared with reference sequences derived from different geographical locations. the results indicated that the virus belongs to the north american type rather than european. comparative analyses of the genetic diversity between th ... | 2009 | 19934596 |
| characterization of the cytokine and maturation responses of pure populations of porcine plasmacytoid dendritic cells to porcine viruses and toll-like receptor agonists. | plausible representatives of plasmacytoid dendritic cells (pdcs) in pigs have been characterized as being cd4(hi)cd172(lo). due to their paucity in blood, we utilized novel fluorescent-activated cell sorting procedures to isolate them from pbmc. the resultant subset was greater than 98% homogeneous in regards to the selected phenotype and contained the preponderance of individuals secreting ifn-alpha after exposure to a known stimulant, transmissible gastroenteritis virus (tgev). in addition to ... | 2010 | 19939462 |
| the minor envelope glycoproteins gp2a and gp4 of porcine reproductive and respiratory syndrome virus interact with the receptor cd163. | porcine reproductive and respiratory syndrome virus (prrsv) contains the major glycoprotein, gp5, as well as three other minor glycoproteins, namely, gp2a, gp3, and gp4, on the virion envelope, all of which are required for generation of infectious virions. to study their interactions with each other and with the cellular receptor for prrsv, we have cloned each of the viral glycoproteins and cd163 receptor in expression vectors and examined their expression and interaction with each other in tra ... | 2010 | 19939927 |
| myristoylation of the small envelope protein of porcine reproductive and respiratory syndrome virus is non-essential for virus infectivity but promotes its growth. | the small envelope (e) protein of porcine reproductive and respiratory syndrome virus (prrsv) is known to possess the properties of an ion-channel protein, and in the present study we show that the prrsv e protein is n-terminal myristoylated. the prrsv e protein contains the consensus motif of (1)mgxxxs(6) for myristoylation, and in the presence of 2-hydroxymyristic acid, the virus titer decreased by 2.5 log tcid(50) and the level of viral rna was reduced significantly. when the glycine at posit ... | 2010 | 19951726 |
| recombinant prrsv expressing porcine circovirus sequence reveals novel aspect of transcriptional control of porcine arterivirus. | porcine reproductive and respiratory syndrome virus (prrsv) expresses its genes via a set of nested subgenomic (sg) mrnas. such discontinuous transcription is unique yet poorly understood for arterivirus. the utilization of transcription-regulating sequence (trs) remains a puzzle, as many trs-like sequences exist in viral genome, yet only six or seven sg mrnas were transcribed in arterivirus infected cells. to investigate the transcriptional control of the porcine arterivirus, a recombinant prrs ... | 2010 | 19951727 |
| recombination in vaccine and circulating strains of porcine reproductive and respiratory syndrome viruses. | em2007, a porcine reproductive and respiratory syndrome virus (prrsv) variant with a unique 68 aa deletion in nsp2, was recently isolated in china. phylogenetic and molecular evolutionary analyses indicated that em2007 is a natural recombinant between a vaccine strain of prrsv and circulating virus. we also tested its pathogenicity in piglets. | 2009 | 19961694 |
| fgi-104: a broad-spectrum small molecule inhibitor of viral infection. | the treatment of viral diseases remains an intractable problem facing the medical community. conventional antivirals focus upon selective targeting of virus-encoded targets. however, the plasticity of viral nucleic acid mutation, coupled with the large number of progeny that can emerge from a single infected cells, often conspire to render conventional antivirals ineffective as resistant variants emerge. compounding this, new viral pathogens are increasingly recognized and it is highly improbabl ... | 2009 | 19966942 |
| porcine reproductive and respiratory syndrome virus attachment is mediated by the n-terminal domain of the sialoadhesin receptor. | sialoadhesin (sn) is an important receptor for viral attachment and internalization of porcine reproductive and respiratory syndrome virus (prrsv) to porcine alveolar macrophages (pam). to investigate whether the n-terminal domain of sn is sufficient and/or necessary for prrsv attachment, we constructed a series of truncated fragments of porcine sn and expressed these in the non-permissive pk15 cell line. the first 150 amino acids comprising the entire first domain of the sn n-terminal region wa ... | 2010 | 19969429 |
| acute phase response in porcine reproductive and respiratory syndrome virus infection. | this study was focused on the changes observed in the serum concentration of haptoglobin (hp), c-reactive protein (crp), serum amyloid a (saa) and pig-major acute protein (pig-map), during experimental porcine reproductive and respiratory syndrome virus (prrsv) infection and in their relationship with the expression of interleukin 1β (il-1β), interleukin 6 (il-6) and tumor necrosis factor alpha (tnf-α). hp and pig-map serum levels were increased at 10 dpi, but crp and saa showed a delayed and hi ... | 2010 | 20004019 |
| a stochastic mathematical model of the within-herd transmission dynamics of porcine reproductive and respiratory syndrome virus (prrsv): fade-out and persistence. | a stochastic, mathematical model of a farrow-finish pig herd was developed and used to investigate the within-herd transmission dynamics of prrsv, and to examine patterns of on-farm persistence and fade-out. the model was structured to represent the management of a typical european pig herd. three parameters determining the natural history of infection were derived from the literature. transmission parameters were chosen using prrsv antibody data from a cross-sectional study of 103 pig herds (ev ... | 2010 | 20004990 |
| identification of two auto-cleavage products of nonstructural protein 1 (nsp1) in porcine reproductive and respiratory syndrome virus infected cells: nsp1 function as interferon antagonist. | the porcine reproductive and respiratory syndrome virus nsp1 is predicted to be auto-cleaved from the replicase polyprotein into nsp1alpha and nsp1beta subunits. in infected cells, we detected the actual existence of nsp1alpha and nsp1beta. cleavage sites between nsp1alpha/nsp1beta and nsp1beta/nsp2 were identified by protein microsequencing analysis. time course study showed that nsp1alpha and nsp1beta mainly localize into the cell nucleus after 10 h post infection. further analysis revealed th ... | 2010 | 20006994 |
| identification of the cd163 protein domains involved in infection of the porcine reproductive and respiratory syndrome virus. | scavenger receptor cd163 is a key entry mediator for porcine reproductive and respiratory syndrome virus (prrsv). to identify the cd163 protein domains involved in prrsv infection, deletion mutants and chimeric mutants were created. infection experiments revealed that scavenger receptor cysteine-rich (srcr) domain 5 (srcr 5) is essential for prrsv infection, while the four n-terminal srcr domains and the cytoplasmic tail are not required. the remaining cd163 protein domains need to be present bu ... | 2010 | 20032174 |
| genetic diversity of porcine reproductive and respiratory syndrome virus (prrsv) in selected herds in a pig-dense region of north-western germany. | the porcine reproductive and respiratory syndrome virus (prrsv) can persist for several weeks in infected pigs, and readily spreads from viraemic pigs to other pigs as well as to other herds. in regions with dense pig populations such as the north-western part of germany the virus is endemic. the aim of this study was to analyse the genetic diversity of prrsv found in 18 herds in this region, which had pigs with respiratory or reproductive failures, and where prrsv had been demonstrated by rt-pc ... | 2010 | 20036085 |
| further assessment of fomites and personnel as vehicles for the mechanical transport and transmission of porcine reproductive and respiratory syndrome virus. | this study re-evaluated the role of fomites and personnel in the mechanical transport and transmission of porcine reproductive and respiratory syndrome virus (prrsv) between pig populations. swabs were collected from hands, boots, coveralls, and other fomites following contact with infected pigs and compared with identical samples collected in the absence of prrsv exposure. naïve pigs were provided contact with contaminated fomites/personnel and blood tested periodically post-exposure [positive ... | 2009 | 20046632 |
| infection dynamics and clinical manifestations following experimental inoculation of gilts at 90 days of gestation with a low dose of porcine reproductive and respiratory syndrome virus. | understanding the dynamics of porcine reproductive and respiratory syndrome virus (prrsv) vertical transmission is important to enhance the accuracy of monitoring protocols for endemically infected breeding herds. the objectives of this study were to determine the prevalence of prrsv within infected litters, to quantify viremia, and to identify specific attributes of infected individuals. eight gilts were intramuscularly inoculated with 10(1) tcid(50) of a mildly virulent prrsv strain (mn-30100) ... | 2009 | 20046633 |
| prevalence of infection with porcine circovirus-2 (pcv-2) and porcine reproductive and respiratory syndrome virus (prrsv) in an integrated swine production system experiencing postweaning multisystemic wasting syndrome. | the objective of this study was to evaluate the prevalence of infection with porcine circovirus-2 (pcv-2) and porcine reproductive and respiratory syndrome virus (prrsv) through a longitudinal study in an integrated swine production system (7 farms) experiencing postweaning multisystemic wasting syndrome (pmws). risk factors for pcv-2 infection and for pcv-2 and prrsv coinfection were also evaluated. fifteen sows from each herd and 4 non-cross-fostered piglets from each sow were randomly selecte ... | 2009 | 20046634 |
| evaluation of porcine reproductive and respiratory syndrome virus replication in laboratory rodents. | porcine reproductive and respiratory syndrome virus (prrsv) is a major cause of economic losses in the swine industry. the disease is widespread worldwide, and so prrsv-negative pigs are often difficult to find for the study of prrsv in vivo. to determine if a small animal model could be developed for prrsv, 3 strains of laboratory rodent were examined for their susceptibility to the virus. no virus replication was detected in balb/c or scid (severe combined immunodeficiency) mice after intraper ... | 2009 | 20046635 |
| gp4 of porcine reproductive and respiratory syndrome virus contains a neutralizing epitope that is susceptible to immunoselection in vitro. | glycoprotein 4 (gp4) of porcine reproductive and respiratory syndrome virus (prrsv) contains a highly variable neutralizing epitope. the present study aimed to investigate whether this epitope is susceptible to immunoselection by antibodies in vitro. cultivation of prrsv in vitro in the continuous presence of neutralizing monoclonal antibodies (mabs) directed against this epitope resulted in the selection of mab-resistant prrsv strains within five passages. comparison of the gp4 amino acid (aa) ... | 2010 | 20052599 |
| immunogenicity of recombinant gp5 protein of porcine reproductive and respiratory syndrome virus expressed in tobacco plant. | the aim of the study was to evaluate the immunogenicity of the orf5-encoded major envelop glycoprotein 5 (gp5) of porcine reproductive and respiratory syndrome virus (prrsv) expressed in tobacco plant as a potential pig oral vaccine in protection against prrsv infection. six-week-old prrsv-free pigs were fed four times orally with 50g of chopped fresh gp5 transgenic tobacco leaves (gp5-t) (gp5 reaching 0.011% of total soluble protein) or wild-type tobacco leaves (w-t) each on days 0, 14, 28, and ... | 2010 | 20053461 |
| a molecular analysis of european porcine reproductive and respiratory syndrome virus isolated in south korea. | in a situation where european genotype of porcine reproductive and respiratory syndrome virus (prrsv) has recently emerged in south korea, this study aims to understand variations in and relatedness among 25 european (eu) genotype 1 prrsv isolates obtained from korean pig farms during the period ranging from 2006 to 2009 for their sequences of nonstructural protein 2 (nsp2), open reading frames (orf) 5 and 7, which, in turn, were compared with those of published korean type 1 prrsv isolates (cp6 ... | 2010 | 20053505 |