Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| porcine reproductive and respiratory syndrome virus infection of alveolar macrophages can be blocked by monoclonal antibodies against cell surface antigens. | prrsv has a restricted macrophage tropism. to explore if the difference in susceptibility of porcine alveolar macrophages (pam) and peripheral blood mononuclear cells (pbmc) to prrsv is correlated with certain cellular surface antigens which may serve as a virus receptor, polyclonal antibodies against pam and pbmc were prepared. anti-pam but not anti-pbmc antibodies protected pam from prrsv infection suggesting that specific receptor(s) may exist on pam. furthermore, monoclonal antibodies (mabs) ... | 1998 | 9782268 |
| an infectious cdna clone of porcine reproductive and respiratory syndrome virus. | a plasmid containing a full-length cdna copy of the lelystad virus isolate (lv) of porcine reproductive and respiratory syndrome virus was constructed. when rna that was transcribed in vitro from this full-length cdna clone was transfected to bhk-21 cells, infectious lv was produced and secreted. the virus was rescued by passage to porcine alveolar lung macrophages or cl2621 cells. when infectious transcripts were transfected to porcine alveolar lung macrophages or cl2621 cells no infectious vir ... | 1998 | 9782281 |
| subgenomic rna7 is transcribed with different leader-body junction sites in prrsv (strain vr2332) infection of cl2621 cells. | porcine reproductive and respiratory syndrome virus (prrsv), like all members of the order nidoviridae, is expressed in the infected cell as a nested set of subgenomic (sg) rnas with a common 5'-leader sequence. we have determined that the 5'-leader sequence for the us prototype strain (vr2332, collins, et al., 1992) is distinct from the european prototype strain [lelystad (lv); wensvoort, et al., 1991, meulenberg et al., 1993a], yet these two strains use almost the same sequence for downstream ... | 1998 | 9782293 |
| in vivo and in vitro interferon (ifn) studies with the porcine reproductive and respiratory syndrome virus (prrsv). | some of the interactions between the porcine reproductive and respiratory syndrome virus (prrsv) and the porcine interferon-alpha (ifn-alpha) system were studied. in a first experiment, it was shown that pretreatment of primary porcine alveolar macrophages (ams) with recombinant porcine (rpo) ifn-alpha 1 resulted in significant reductions of prrsv yield and numbers of antigen expressing cells. in a second experiment, sensitivity of prrsv to ifn-alpha was confirmed in vivo. in pigs inoculated wit ... | 1998 | 9782316 |
| identification of a common antigenic site in the nucleocapsid protein of european and north american isolates of porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) nucleocapsid (n) protein has been identified as the most immunodominant viral protein. the n protein genes from two prrsv isolates olot/91 (european) and quebec 807/94 (north american) were cloned and expressed in escherichia coli using the pet3x system. the antigenic structure of the prrsv n protein was dissected using seven monoclonal antibodies (mabs) and overlapping fragments of the protein expressed in e.coli. three antigenic sites ... | 1998 | 9782317 |
| arterivirus prrsv. experimental studies on the pathogenesis of respiratory disease. | pigs were infected with the porcine respiratory and reproductive syndrome virus (prrsv) by the oronasal route. we studied the development of histological lesions, sites of virus infection and of inflammatory infiltrates by quantitative evaluation of reactive cells. the animals developed a multifocal interstitial pneumonia. clinical signs of pneumonia were observed from day 7 to 21. in the first stage, an acute alveolitis was found, which was characterised by a hyperplasia of type ii pneumocytes ... | 1998 | 9782334 |
| european serotype prrsv vaccine protects against european serotype challenge whereas an american serotype vaccine does not. | pigs were either vaccinated with an american serotype porcine reproductive and respiratory syndrome virus (prrsv) vaccine or with a european serotype vaccine. a control group of was left unvaccinated. at four weeks after vaccination the prrsv-specific antibody titres were determined and one third of each group was challenged with a spanish, one third with a german and one third with a dutch prrsv wild type strain. the serological responses, measured at 4 weeks after vaccination, confirmed that b ... | 1998 | 9782349 |
| genetic variation in the prrs virus. | porcine reproductive and respiratory syndrome (prrs) is characterized by late-term abortions and stillbirths in sows and respiratory difficulties in nursery pigs. the disease appeared in europe and north america at approximately the same time between 1985 and 1990. the prrs virus was isolated shortly thereafter and demonstrated unexpectedly profound differences between european (lelystad) and north american (vr2332) isolates as measured by serological crossreactivity and nucleotide sequence simi ... | 1998 | 9782359 |
| sequence analysis of the nucleocapsid protein gene of the porcine reproductive and respiratory syndrome virus taiwan md-001 strain. | the 3'-portion of the genome from a taiwan isolate of porcine reproductive and respiratory syndrome (prrs) virus, strain md-001, was cloned and sequenced. the resultant 549 nucleotides contained an open reading frame with a coding capacity of 123 amino acids (predicted mr 13,600). the predicted protein corresponds to the nucleocapsid protein, the gene product of orf7. comparative sequence analysis of several known prrsv strains indicated that this protein showed the highest degree of amino acid ... | 1998 | 9782360 |
| sequence analysis of porcine reproductive and respiratory syndrome virus of the american type collected from danish swine herds. | vaccine-like viruses of american type of porcine reproductive and respiratory syndrome virus (prrsv) were detected in serum samples by rt-pcr. the viruses were analysed by nucleotide sequencing of the genomic region encoding open reading frames 2 to 7. during the ongoing study of danish isolates of prrsv by means of nucleotide sequencing, rt-pcr reactions and subsequent nucleotide sequencing showed the presence of american type prrsv in danish breeding herds. most likely, these atypical viruses ... | 1998 | 9787654 |
| the reverse transcription polymerase chain reaction for the diagnosis of porcine reproductive and respiratory syndrome: comparison with virus isolation and serology. | a single-tube reverse transcription polymerase chain reaction (rt-pcr) assay for the detection of porcine reproductive and respiratory syndrome (prrs) virus in blood samples from infected pigs was developed. this test was assessed for sensitivity and application as a rapid diagnostic tool by comparison with virus isolation and detection of prrs virus antibody in blood. the rt-pcr test was slightly more sensitive than virus isolation for detection of virus in serum and markedly more sensitive tha ... | 1998 | 9791868 |
| [boar semen--a possible risk factor in infection occurrence of porcine reproductive and respiratory syndrome]. | based on an experimental study using two and six prrs-negative young boars and gilts, respectively, it was proven wether boar semen could be a risk factor in the transmission of the disease. the two boars were inoculated intranasally with the prrs-virus strain i10 (intervet) containing 107 tcid50/ml. using ovulation synchronization six gilts were prepared as bioindicators to be inseminated, two of them with semen of the two boars at day 4, 8 and 12 after infection. following inoculation of the b ... | 1998 | 9793235 |
| effect of porcine reproductive and respiratory syndrome virus infection on the clearance of haemophilus parasuis by porcine alveolar macrophages. | porcine reproductive and respiratory syndrome virus (prrsv) infection in young piglets is frequently associated with secondary infection due to various pathogens, especially those of the respiratory tract. one of the most important mechanisms in respiratory diseases is related to the alteration of function of porcine alveolar macrophages (pams). the objective of this study was to determine how prrs virus infection affects the capabilities of pams in the phagocytosis and destruction of haemophilu ... | 1998 | 9798089 |
| antigenic structure of the nucleocapsid protein of porcine reproductive and respiratory syndrome virus. | a collection of 12 monoclonal antibodies (mabs) raised against porcine reproductive and respiratory syndrome (prrs) virus was used to study the antigenic structure of the virus nucleocapsid protein (n). the full-length n gene, encoded by open reading frame 7, was cloned from the canadian prrs virus, pa-8. deletions were introduced into the n gene to produce a series of nine overlapping protein fragments ranging in length from 25 to 112 amino acids. the individual truncated genes were cloned as g ... | 1998 | 9801333 |
| serosurvey of selected viral and bacterial diseases in wild swine from oklahoma. | blood samples collected from 120 wild swine (sus scrofa) in thirteen oklahoma (usa) counties during 1996 were tested for antibodies against six viral and two bacterial diseases. no antibodies to swine brucellosis, pseudorabies, transmissible gastroenteritis, and vesicular stomatitis were detected. antibody titers to one or more leptospiral serovars were found in 44% of the samples, the two most frequent serovars being leptospira interrogans serovars bratislava (29%) and pomona (27%). antibody ag ... | 1998 | 9813859 |
| apoptosis induced in vivo during acute infection by porcine reproductive and respiratory syndrome virus. | we studied apoptosis caused by porcine reproductive and respiratory syndrome virus (prrsv) in vivo, focusing on the tissues that constitute the main targets for infection: lung and lymphoid tissues. previous investigators have shown that the prrsv glycoprotein p25, encoded by prrsv open reading frame 5, induces apoptosis when expressed in cos-1 cells. results of studies conducted in our laboratory indicate the simultaneous occurrence of prrsv-induced alterations of spermatogenesis and apoptotic ... | 1998 | 9823592 |
| elimination of porcine reproductive and respiratory syndrome virus using a test and removal process. | 1998 | 9829305 | |
| cutaneous and systemic necrotizing vasculitis in swine. | a systemic vasculitis involving particularly the skin and kidneys has been recently described in swine under the name dermatitis/nephropathy syndrome. twelve pigs with gross cutaneous lesions typical of this condition were necropsied, and morphologic, immunohistochemical, microbiologic, and epidemiologic characteristics were studied. the pigs were divided into three groups comprising eight pigs with acute lesions, two with chronic lesions, and two with acute lesions kept for sequential skin biop ... | 1998 | 9539364 |
| porcine reproductive and respiratory syndrome. | in 1987, porcine reproductive and respiratory syndrome (prrs) was recognized in the usa as a new disease of swine causing late-term reproductive failure and severe pneumonia in neonatal pigs. the syndrome is caused by an rna virus referred to as prrs virus (prrsv), which is classified in the family arteriviridae. swine macrophages are the only indigenous cell type known to support prrsv replication. direct contact between infected and naive pigs is the predominant route of prrsv transmission. ex ... | 1998 | 9545131 |
| differentiation between porcine reproductive and respiratory syndrome virus isolates by restriction fragment length polymorphism of their orfs 6 and 7 genes. | three distinct antigenic profiles were identified by comparing the reactivities of 15 canadian field isolates, the attenuated u.s. vaccine (ingelvac mlv) strain and 2 european reference strains (lelystad and weybridge) of the porcine reproductive and respiratory syndrome virus (prrsv) by indirect immunofluorescence with a set of 4 monoclonal antibodies to the nucleocapsid (n) protein and 2 other to the matrix (m) protein. in the present study, 9 canadian isolates for which the sequences were det ... | 1998 | 9553709 |
| identification of a putative receptor for porcine reproductive and respiratory syndrome virus on porcine alveolar macrophages. | to identify the receptor which may determine the macrophage tropism of porcine reproductive and respiratory syndrome virus (prrsv), monoclonal antibodies (mabs) against porcine alveolar macrophages (pam) were produced. two mabs (41d3 and 41d5) which completely blocked prrsv infection of pam were further characterized. it was found that they reduce the attachment of prrsv to pam and immunoprecipitate a 210-kda membrane protein from pam. this protein was detected on the cell membranes of pam but n ... | 1998 | 9557752 |
| comparative sequence analysis of open reading frames 2 to 7 of the modified live vaccine virus and other north american isolates of the porcine reproductive and respiratory syndrome virus. | to elucidate changes associated with the attenuated virulence in a modified live porcine reproductive and respiratory syndrome (prrs) vaccine (boehringer ingelheim animal health, st. joseph, mo), derived from an american prototype atcc virus vr-2332, nucleotide sequence of 3' genome covering open reading frames (orfs) 2 to 7 coding regions from the vaccine virus was determined by rt-pcr with two overlapping fragments. comparisons showed 98 base changes (94 substitutions, 3 deletions, and 1 addit ... | 1998 | 9572560 |
| differentiation of a porcine reproductive and respiratory syndrome virus vaccine strain from north american field strains by restriction fragment length polymorphism analysis of orf 5. | the suitability of restriction fragment length polymorphism (rflp) analysis for differentiating a porcine reproductive and respiratory syndrome virus (prrsv) vaccine strain from other north american field strains was investigated. open reading frame 5 nucleotide sequence data of the vaccine virus, its parent strain vr-2332, and 22 other strains of prrsv included in this study indicated that 3 restriction enzyme gel patterns characterize the vaccine virus and the parent strain genotype. the combi ... | 1998 | 9576340 |
| ultrastructural study of porcine alveolar macrophages infected in vitro with porcine reproductive and respiratory syndrome (prrs) virus, with and without haemophilus parasuis. | two experiments were designed to study ultrastructural changes in porcine alveolar macrophages (pam) inoculated with porcine reproductive and respiratory syndrome (prrs) virus (experiment 1) and with prrs virus and haemophilus parasuis (experiment 2). in both experiments, the viral infectious dose represented a "multiplicity of infection" of 1. viral infection alone induced minimal ultrastructural changes at this dose, consisting only of an increase in lysosome numbers. mixed viral and bacterial ... | 1998 | 9595354 |
| immune response in pigs vaccinated with plasmid dna encoding orf5 of porcine reproductive and respiratory syndrome virus. | the orf5-encoded major envelope glycoprotein (gp5) of porcine reproductive and respiratory syndrome virus (prrsv) is one of the three major structural proteins of this virus. while some porcine convalescent sera and monoclonal antibodies directed against gp4 and gp5 have the capacity to neutralize the virus in vitro, the protein specificity of porcine neutralizing sera has not yet been established. dna immunization with a plasmid encoding gp5 of prrsv, under the control of a human cytomegaloviru ... | 1998 | 9603313 |
| porcine dermatitis and nephropathy syndrome in spain. | in august 1995, the first case of porcine dermatitis and nephropathy syndrome was diagnosed in the north-eastern part of spain; the pig showed characteristic dermal and renal lesions. between then and january 1996, nine further animals from five different herds were diagnosed; they showed signs of anorexia, depression and, sometimes, pyrexia. diarrhoea, glässer's disease, conjunctivitis and gastric ulcers also occurred on the farms where the diagnoses were made. the affected pigs died of renal f ... | 1998 | 9612914 |
| inducible nitric oxide synthase expression in porcine immune cells. | porcine immune cells were examined for the ability to produce inducible nitric oxide synthase following in vitro or in vivo stimulation. enzyme activity and product formation were not detected following stimulation of porcine peripheral blood mononuclear cells (pbmc), splenocytes, or alveolar macrophages with a combination of cona and lipopolysaccharide (lps) or recombinant porcine interferon gamma and lps. in vitro engulfment of haemophilus parasuis by macrophages also failed to induce inducibl ... | 1998 | 9613441 |
| immune responses in pigs infected with porcine reproductive and respiratory syndrome virus (prrsv). | in three successive experiments, the immune functions of pigs persistently infected with the porcine reproductive and respiratory syndrome virus (prrsv) have been evaluated. non-specific immune responses were analyzed over a period of 12 weeks post-infection (pi). in addition, the capacity of prrsv-infected pigs to develop an efficient immune response against pseudorabies virus (prv) glycoproteins and to resist to a subsequent virulent challenge was investigated. our results demonstrate that prr ... | 1998 | 9613472 |
| effect on viraemia of an american and a european serotype prrsv vaccine after challenge with european wild-type strains of the virus. | three groups of 10 pigs were vaccinated with an american serotype porcine reproductive and respiratory syndrome virus (prrsv) vaccine and three groups of 10 pigs were vaccinated with a european serotype prrsv vaccine. a control group of 12 pigs was left unvaccinated. four weeks after vaccination the prrsv-specific antibody titres were determined and each group was challenged with either a spanish, german or dutch prrsv wild-type strain. the serological responses four weeks after vaccination conf ... | 1998 | 9618874 |
| cellular membrane factors are the major determinants of porcine reproductive and respiratory syndrome virus tropism. | the mechanism that restricts porcine reproductive and respiratory syndrome virus (prrsv) replication in a variety of cell-lines has been investigated in this study. using a virus binding assay, it was found that prrsv could not bind to most cell-lines tested. however, vero cells, which are non-permissive to prrsv infection, were able to bind and internalize a virus almost as efficiently as the permissive cell-line marc-145. in addition, marc-145 and vero cells internalized prrsv in an infectious ... | 1998 | 9620204 |
| [incidence of antibodies in raccoon dogs and deer inhabiting suburban areas]. | we evaluated the incidence of antibodies against canine distemper (cd) virus, canine parvovirus, toxoplasma gondii (t. gondii), aujeszky's disease virus, porcine reproductive and respiratory syndrome virus, rickettsia tsutsugamushi, rickettsia japonica, and coxiella burnetii in 30 raccoon dogs and 5 deer captured in suburban areas in kanagawa prefecture. among the raccoon dogs, anti-t. gondii antibody was detected in 1 animal (3.3%) and anti-cd virus antibody in 9 (30.0%). however, antibodies ag ... | 1998 | 9621559 |
| attempted elimination of porcine reproductive and respiratory syndrome virus from a seedstock farm by vaccination of the breeding herd and nursery depopulation. | an attempt was made to eliminate the virus of porcine reproductive and respiratory syndrome from a seedstock farm by using the combined strategies of vaccination and nursery depopulation. the breeding herd was vaccinated with a modified-live virus vaccine; all breeding and lactating adult animals were vaccinated twice, with a 30-day interval between vaccinations. all the sows were vaccinated in this way except for those in the third trimester of gestation (66 to 114 days) which were vaccinated o ... | 1998 | 9634705 |
| dual infection with enterotoxigenic escherichia coli and porcine reproductive and respiratory syndrome virus observed in weaning pigs that died suddenly. | diarrhea, sudden death after short duration of diarrhea and sudden death without apparent signs were observed in a herd of breeder pigs. five pigs that died suddenly with diarrhea (sdd pigs) and 6 pigs that died suddenly without signs (sd pigs) were examined. the average age of the pigs was about 28 days. twelve pigs of age 10 to 14 days old showing diarrhea (d pigs) were also examined. eleven of them recovered. large numbers of escherichia coli were detected in all organs of every sdd and sd pi ... | 1998 | 9637287 |
| field isolates of transmissible gastroenteritis virus differ at the molecular level from the miller and purdue virulent and attenuated strains and from porcine respiratory coronaviruses. | the diversity in selected regions of the transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv) genomes was analyzed among known tgev and prcv strains and field isolates. the n-terminal half of the spike (s) glycoprotein gene and open reading frames (orf) 3, 3-1 and 4 were amplified by reverse transcriptase reaction and polymerase chain reaction (rt/pcr), and analyzed using restriction fragment length polymorphism (rflp) patterns of the amplified dna. reference tge ... | 1998 | 9637293 |
| blocking elisa's for the distinction between antibodies against european and american strains of porcine reproductive and respiratory syndrome virus. | a double blocking elisa was developed in order to satisfy the need for large scale serological screening for prrs and simultaneous distinction between infection with european and american strains of prrsv in pig herds. the immunoperoxidase monolayer assay (ipma) and the double blocking elisa enabled distinction on serological basis between infection with european and american strains of prrsv. the distinction was possible from about day 7 after infection of pigs with prrsv. the double blocking e ... | 1998 | 9646448 |
| experimental inoculation of swine at various stages of gestation with a danish isolate of porcine reproductive and respiratory syndrome virus (prrsv). | following intranasal inoculation of three groups of pregnant swine (in total 11 dams) with a danish isolate of porcine reproductive and respiratory syndrome virus (prrsv) on or about day 85, 70 and 45 of gestation, respectively, reproductive disturbances were observed in the first two groups. transplacental transmission of prrsv occurred in four out of five litters from dams inoculated around day 85 of gestation and in two out of three litters from dams inoculated on day 72 of gestation. in the ... | 1998 | 9646462 |
| a subset of porcine reproductive and respiratory syndrome virus gp3 glycoprotein is released into the culture medium of cells as a non-virion-associated and membrane-free (soluble) form. | the gp3 protein of the iaf-klop strain of porcine reproductive and respiratory syndrome virus (prrsv) was expressed in 293 cells by a recombinant human type 5 adenovirus carrying the open reading frame 3 gene. the protein exhibited a molecular mass of 42 kda and comigrated with gp3 expressed in prrsv-infected marc-145 cells. removal of n-linked glycans from gp3 resulted in a 27-kda protein (p3), confirming its highly glycosylated nature. pulse-chase experiments carried out either in the context ... | 1998 | 9658068 |
| molecular variation in the nucleoprotein gene (orf7) of the porcine reproductive and respiratory syndrome virus (prrsv). | the nucleoprotein gene (orf7) of 15 european isolates of porcine reproductive and respiratory syndrome virus (prrsv) was sequenced and compared with corresponding sequences of other prrsv isolates (2 european and 13 american) and one isolate each of other arteriviruses (the lactate dehydrogenase elevating virus (ldv), the simian haemorrhagic fever virus (shfv) and the equine arteritis virus (eav)). their phylogenetic relationships were established using neighbour-joining and parsimony methods. f ... | 1998 | 9660067 |
| pcr analysis for the identification of porcine reproductive and respiratory syndrome virus in boar semen. | 1998 | 9664505 | |
| quantitation of porcine reproductive and respiratory syndrome virus rna in semen by single-tube reverse transcription-nested polymerase chain reaction. | porcine reproductive and respiratory syndrome virus (prrsv) is in boar semen for extended periods of time as determined by reverse transcription-nested polymerase chain reaction (rt-npcr) assay. the concentration of prrsv rna in semen and the biological significance of the detection level, however, remain to be resolved. in order to determine the concentration of prrsv vr-2332 (a prototypic strain of north american isolates) in semen following infection, we established a 'standard curve'-quantit ... | 1998 | 9672134 |
| monoclonal antibodies against conformationally dependent epitopes on porcine reproductive and respiratory syndrome virus. | monoclonal antibodies (mabs) against porcine reproductive and respiratory syndrome virus (prrsv) were prepared and characterized. four mabs were developed from the mice immunized with the recombinant gp4 protein expressed in insect cells, and six mabs were derived from the immunization with recombinant gp5 protein. all of the mabs showed strong perinuclear fluorescence in prrsv vr2385 infected cells by immunofluorescence staining. among the mabs to gp5 protein, one showed strong reactivity in el ... | 1998 | 9850993 |
| influence of pig age on virus titer and bactericidal activity of porcine reproductive and respiratory syndrome virus (prrsv)-infected pulmonary intravascular macrophages (pims). | twelve pigs (six 4-week-old and six 4-month-old cross-bred, specific pathogen free pigs) were used as donors for both pulmonary intravascular macrophages (pims) and pulmonary alveolar macrophages (pams). the pims and pams were infected in vitro with low (isu-55) or high (vr-2385) virulence strains of prrsv at 1 multiplicity of infection (m.o.i.) for comparisons of virus titers at 48 h post infection (pi). pims were as permissive as pams to infection with both prrsv isolates yielding similar prog ... | 1998 | 9850997 |
| a nonstructural and antigenic glycoprotein is encoded by orf3 of the iaf-klop strain of porcine reproductive and respiratory syndrome virus. | open reading frame 3 (orf3) of the genome of porcine reproductive and respiratory syndrome virus (prrsv), quebec strain iaf-klop, was reverse-transcribed and cloned into the procaryotic expression vector pgex-4t-1, then subcloned into the eucaryotic expression vector padcmv5 which was used as a shuttle vector to generate a replication-defective recombinant adenovirus. the procaryotic gst-orf3 recombinant fusion protein was used to raise a monospecific antiserum in rabbits. by western-immunoblott ... | 1998 | 9856081 |
| clinical consequences of exposing pregnant gilts to strains of porcine reproductive and respiratory syndrome (prrs) virus isolated from field cases of "atypical" prrs. | to determine clinical consequences of exposing pregnant gilts to strains of porcine reproductive and respiratory syndrome (prrs) virus (prrsv) isolated from field cases of "atypical" or "acute" prrs in vaccinated herds. | 1998 | 9858403 |
| sensitive detection and typing of porcine reproductive and respiratory syndrome virus by rt-pcr amplification of whole viral genes. | following the recent use of a live vaccine against porcine reproductive and respiratory syndrome virus (prrsv) in denmark, both american (vaccine) and european-type prrsv now coexist in danish herds. this situation highlighted a requirement for supplementary tests for precise virus-typing. as a result, we developed a rt-pcr assay able to detect as well as type prrsv. to provide maximal sequence information, complete viral open reading frames (orfs 5 and 7) were targeted for amplification. the rt ... | 1998 | 9874099 |
| localization and fine mapping of antigenic sites on the nucleocapsid protein n of porcine reproductive and respiratory syndrome virus with monoclonal antibodies. | the purpose of this study was to analyze the antigenic structure of the nucleocapsid protein n of the lelystad virus isolate of porcine reproductive and respiratory syndrome virus (prrsv) and to identify antigenic differences between this prototype european isolate and other north american isolates. to do this, we generated a panel of monoclonal antibodies (mabs) directed against the n protein of lelystad virus and tested them in competition assays with other n-specific mabs described previously ... | 1998 | 9875321 |
| experimental infection of maternally immune pigs with porcine reproductive and respiratory syndrome (prrs) virus. | to investigate the influence of maternal antibody to porcine reproductive and respiratory syndrome (prrs) virus infection, the following examination was done using conventional and spf pigs. ten 17-day-old conventional pigs with maternal antibody against prrs virus and 6 44-day-old spf pigs seronegative were inoculated intranasally with 10(5.0) tcid50 of prrs virus. two conventional and 4 spf pigs were served as non-inoculated control. in conventional pigs, coughing and febrile response were obs ... | 1998 | 9879527 |
| a pneumo-virulent united states isolate of porcine reproductive and respiratory syndrome virus induces apoptosis in bystander cells both in vitro and in vivo. | evidence of apoptosis was detected for the united states porcine reproductive and respiratory syndrome virus (prrsv) in atcc crl11171 cells inoculated with strain atcc vr2385 and in the tissues of pigs infected with the same strain. apoptosis was detected by agarose gel electrophoresis, transmission electron microscopy and terminal deoxytransferase dutp nick end labelling (tunel) techniques. by electron microscopy and double-labelling techniques, apoptosis was detected primarily in uninfected by ... | 1998 | 9880013 |
| infectious transcripts from cloned genome-length cdna of porcine reproductive and respiratory syndrome virus. | the 5'-terminal end of the genomic rna of the lelystad virus isolate (lv) of porcine reproductive and respiratory syndrome virus was determined. to construct full-length cdna clones, the 5'-terminal sequence was ligated to cdna clones covering the complete genome of lv. when rna that was transcribed in vitro from these full-length cdna clones was transfected into bhk-21 cells, infectious lv was produced and secreted. the virus was rescued by passage to porcine alveolar lung macrophages or cl2621 ... | 1998 | 9420236 |
| clinical effects of porcine reproductive and respiratory syndrome virus on pigs during the early postnatal interval. | to determine the effect of congenital and early postnatal infection of pigs with porcine reproductive and respiratory syndrome virus (prrsv) on postnatal survival and growth. | 1998 | 9442243 |
| evidence of freedom from porcine reproductive and respiratory syndrome virus infection in switzerland. | 1998 | 9507649 | |
| characterization of antibody response to porcine reproductive and respiratory syndrome virus orf5 product following infection and evaluation of its diagnostic use in pigs. | the sensitivity and specificity of recombinant open reading frame 5 products used in the western blotting assay for confirmation of porcine reproductive and respiratory syndrome virus (prrsv) serologic status were evaluated. the recombinant antigen-based assays were specifically compared with a commercial enzyme-linked immunosorbent assay (elisa) for prrsv antibodies using 1) prrsv antibody-negative reference sera (n = 30), 2) naturally infected pig sera (n = 40), 3) sequential sera obtained fro ... | 1999 | 12968750 |
| diagnostic implications of concurrent inoculation with attenuated and virulent strains of porcine reproductive and respiratory syndrome virus. | to determine the predominant strain of progeny virus in samples obtained from cell cultures and pigs exposed simultaneously to attenuated and virulent strains of porcine reproductive and respiratory syndrome virus (prrsv). | 1999 | 9918159 |
| seroneutralization of porcine reproductive and respiratory syndrome virus correlates with antibody response to the gp5 major envelope glycoprotein. | to determine the structural protein of the porcine reproductive and respiratory syndrome virus (prrsv) involved in the production of neutralizing antibodies following clinical infection, correlation was studied between virus neutralization capability of convalescent pig sera and antibody response to the open reading frames (orfs) 3-, 4-, 5-, and 7-encoded proteins gp3, gp4, gp5, and n, respectively. individual virus genes were cloned into the pgex-4t-1 vector, and the recombinant viral proteins ... | 1999 | 9925207 |
| detection of porcine reproductive and respiratory syndrome virus by reverse transcription-polymerase chain reaction using different regions of the viral genome. | serologic studies have revealed strain variability between american and european isolates and among american isolates of porcine reproductive and respiratory syndrome virus (prrsv). the objective of this study was to develop an assay for the routine diagnosis of prrsv in field specimens using reverse transcription-polymerase chain reaction (rt-pcr) amplification of conserved genomic regions. twenty-four field isolates of prrsv from different regions of the usa were analyzed in the study. six pri ... | 1999 | 9925208 |
| mycoplasma hyopneumoniae potentiation of porcine reproductive and respiratory syndrome virus-induced pneumonia. | an experimental model that demonstrates a mycoplasma species acting to potentiate a viral pneumonia was developed. mycoplasma hyopneumoniae, which produces a chronic, lymphohistiocytic bronchopneumonia in pigs, was found to potentiate the severity and the duration of a virus-induced pneumonia in pigs. pigs were inoculated with m. hyopneumoniae 21 days prior to, simultaneously with, or 10 days after inoculation with porcine reproductive and respiratory syndrome virus (prrsv), which induces an acu ... | 1999 | 9986823 |
| porcine reproductive and respiratory syndrome virus and haemophilus parasuis antigen distribution in dually infected pigs. | immunohistochemical, viral and bacterial isolation techniques were used to study the distribution and localization of porcine reproductive and respiratory syndrome virus (prrsv) and haemophilus (h.) parasuis in experimentally infected pigs. thirty pigs seronegative to prrsv and h. parasuis were divided into four groups. group a pigs (10 animals) were inoculated with both virus and bacteria; group b pigs (10 animals) were inoculated with bacteria, group c pigs (five animals) were inoculated with ... | 1999 | 10063534 |
| entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis. | porcine alveolar macrophages (amphi) are the dominant cell type that supports the replication of porcine reproductive and respiratory syndrome virus (prrsv) in vivo and in vitro. in order to determine the characteristics of the virus-receptor interaction, the attachment of prrsv to cells was examined by using biotinylated virus in a series of flow cytometric assays. prrsv bound specifically to amphi in a dose-dependent manner. binding of prrsv to amphi increased gradually and reached a maximum w ... | 1999 | 10073688 |
| north american and european porcine reproductive and respiratory syndrome viruses differ in non-structural protein coding regions. | although north american and european serotypes of porcine reproductive and respiratory syndrome virus (prrsv) are recognized, only the genome of the european lelystad strain (lv) has been sequenced completely. here, the genome of the pathogenic north american prrsv isolate 16244b has been sequenced and compared with lv. the genomic organization of 16244b was the same as lv but with only 63.4% nucleotide identity. the 189 nucleotide 5' non-coding region (ncr) of 16244b was distinct from the lv nc ... | 1999 | 10073689 |
| t cell responses to the structural polypeptides of porcine reproductive and respiratory syndrome virus. | the identification of antigens recognized by t cell responses has become fundamental for developing effective immunizations against viral infections. lymphocyte proliferation and delayed-type hypersensitivity responses to porcine reproductive and respiratory syndrome virus (prrsv) infection have been demonstrated. however, the polypeptide specificity of t cell responses to prrsv is unknown. to identify the prrsv polypeptides recognized by porcine lymphocytes two approaches were employed. first p ... | 1999 | 10076513 |
| a modified immunoperoxidase assay for detection of antibody porcine reproductive and respiratory syndrome (prrs) virus in swine sera. | marc-145 cell monolayers infected with prrs virus were fixed in 3% neutral buffered formalin and embedded in paraffin. the sections were stained by avidin-biotin complex immunoperoxidase (abc) method. test sera were applied to sections as primary antibodies. the positive reactions were detected by abc method and indirect immunofluorescent assay (ifa). there was good correlation between abc and ifa, and the titers in abc were higher than those in ifa. the present results indicate that the immunoh ... | 1999 | 10081764 |
| pathological, immunohistochemical, and in-situ hybridization studies of natural cases of postweaning multisystemic wasting syndrome (pmws) in pigs. | fifteen pigs from five farms on which there had been a previous clinical and histopathological diagnosis of postweaning multisystemic wasting syndrome (pmws) were investigated. at necropsy, enlargement of lymph nodes was the most obvious lesion; other lesions were non-collapsed lungs, ulceration of the gastric pars oesophagica, and cranioventral pulmonary consolidation. microscopical lesions attributable to pmws were found in lymphoid organs (including lymph nodes, tonsil, peyer's patches and sp ... | 1999 | 10098016 |
| distribution of a korean strain of porcine reproductive and respiratory syndrome virus in experimentally infected pigs, as demonstrated immunohistochemically and by in-situ hybridization. | in an experiment with 40 specific pathogen-free pigs aged 3 days, the distribution of a korean isolate of porcine reproductive and respiratory syndrome virus (prrsv) was assessed immunohistochemically and by in-situ hybridization for a period of 28 days after intranasal inoculation. the most consistent and intense labelling for prrsv was in the lung, the virus persisting in pulmonary macrophages for at least 28 days. the middle lobe of the lung was the optimum site for the detection of prrsv ant ... | 1999 | 10098017 |
| identification and clinical assessment of suspected vaccine-related field strains of porcine reproductive and respiratory syndrome virus. | to determine the origin and clinical relevance of selected strains of porcine reproductive and respiratory syndrome (prrs) virus (prrsv). | 1999 | 10188816 |
| evidence for divergence of restriction fragment length polymorphism patterns following in vivo replication of porcine reproductive and respiratory syndrome virus. | to determine stability of the restriction fragment length polymorphism (rflp) pattern of a porcine reproductive and respiratory syndrome vaccine virus and patterns of other viral strains as they replicate in pigs. | 1999 | 10211690 |
| effect of porcine reproductive and respiratory syndrome virus (prrsv) on alveolar lung macrophage survival and function. | porcine reproductive and respiratory syndrome virus (prrsv) recently emerged as an important cause of reproductive disorders and pneumonia in domestic pigs throughout the world. acute cytocidal replication of prrsv in alveolar lung macrophages causes the acute pneumonia; however, it remains largely unresolved whether there may also be a predisposition to longer-term local immunodeficiency in the prrsv-convalescent lung. we applied various flow cytometric techniques to study the interplay between ... | 1999 | 10223319 |
| antigenic and genetic variations of the 15 kd nucleocapsid protein of porcine reproductive and respiratory syndrome virus isolates. | the antigenic variability of the 15 kd nucleocapsid protein of porcine reproductive and respiratory syndrome (prrs) virus was characterized with a panel of 24 monoclonal antibodies (mabs) raised against the american prrs virus isolate isu-p. five continuous epitopes designated eporf7-a through e were revealed by the reactivity pattern of these mabs with 67 american field isolates, two modified-live vaccine viruses, and the european lelystad virus as determined by the indirect immnofluorescence a ... | 1999 | 10226618 |
| monoclonal antibodies to the gp5 of porcine reproductive and respiratory syndrome virus are more effective in virus neutralization than monoclonal antibodies to the gp4. | the arterivirus porcine reproductive and respiratory syndrome virus (prrsv) contains six structural proteins the roles of which are not completely understood. in a preceding study, immunization with the dutch isolate i10 of prrsv had led to the development of mabs against four structural proteins [wieczorek-krohmer, m., 1994. herstellung und charakterisierung von monoklonalen antikörpern gegen das virus des porzinen reproduktiven und respiratorischen syndroms (prrsv). inaugural-dissertation, lud ... | 1999 | 10227120 |
| "the clinical scope of porcine reproductive and respiratory syndrome virus infection has expanded since 1987": an alternative perspective. | 1999 | 10332837 | |
| porcine reproductive and respiratory syndrome virus infection in neonatal pigs characterised by marked neurovirulence. | neonatal pigs from three herds of pigs were somnolent and inappetent and had microscopic lesions characterised by severe meningoencephalitis, necrotic interstitial pneumonia and gastric muscular inflammation. porcine reproductive and respiratory syndrome virus (prrsv) infection was diagnosed and confirmed by virus isolation, fluorescent antibody examination of frozen lung sections, serology, immunohistochemistry and in situ hybridisation. each herd had a history of prrsv infection and was using ... | 1999 | 10343377 |
| a sensitive fluorescence in situ hybridization technique for detection of porcine reproductive and respiratory syndrome virus. | a sensitive fluorescence in situ hybridization (ish) for detecting porcine reproductive and respiratory syndrome virus (prrsv) rna in viral infected tissue was developed using digoxigenin-labeled rna probes targeted on the nucleocapsid gene of prrsv. in situ rna/rna hybrids were detected with an anti-digoxigenin antibody alkaline phosphatase conjugate and further revealed with fast red tr salt/naphthol as-mx phosphate using a fluorescent microscope. viral nucleic acid was readily demonstrated wi ... | 1999 | 10381083 |
| the evolution of porcine reproductive and respiratory syndrome virus: quasispecies and emergence of a virus subpopulation during infection of pigs with vr-2332. | gp5, the principal envelope glycoprotein of porcine reproductive and respiratory syndrome virus (prrsv), contains a hypervariable region within the ectodomain which is responsible for generating diversity in field isolates. the purpose of this study was to gain insight into the possible origin of this diversity by following gp5 sequence changes in pigs exposed to prrsv strain vr-2332 in utero. a region of the prrs virus genome containing portions of orf4 and orf5 was amplified directly from tiss ... | 1999 | 10388650 |
| safety and efficacy of vaccination of pregnant gilts against porcine reproductive and respiratory syndrome. | to determine the safety and efficacy of vaccination of pregnant gilts with an attenuated strain of porcine reproductive and respiratory syndrome virus (prrsv). | 1999 | 10407469 |
| restriction fragment length polymorphism analysis of strains of porcine reproductive and respiratory syndrome virus by use of a nested-set reverse transcriptase-polymerase chain reaction. | to increase the timeliness and sensitivity of a procedure that uses viral nucleic acid amplification followed by restriction fragment length polymorphism (rflp) analysis for identifying strains of porcine reproductive and respiratory syndrome virus (prrsv). | 1999 | 10407470 |
| determination of 5'-leader sequences from radically disparate strains of porcine reproductive and respiratory syndrome virus reveals the presence of highly conserved sequence motifs. | we determined the untranslated 5'-leader sequence for three different isolates of porcine reproductive and respiratory syndrome virus (prrsv): pathogenic european- and american-types, as well as an american-type vaccine strain. 5'-leader from european- and american-type prrsv differed in length (220 and 190 nt, respectively), and exhibited only approximately 50% nucleotide homology. nevertheless, highly conserved areas were identified in the leader of all 3 prrsv isolates, which constitute candi ... | 1999 | 10416379 |
| the reproductive performance of sows after prrs vaccination depends on stage of gestation. | in order to minimize the effects of porcine reproductive and respiratory syndrome (prrs) on stillbirth, mummification, and neonatal mortality in swine herds, many producers have vaccinated their herds using a modified-live virus vaccine. the purpose of this study was to determine the association of the prrs modified-live vaccine and reproductive performance by stage of gestation when the vaccine was administered. a total of 47 swine herds from ontario and manitoba, canada, and from the mid-weste ... | 1999 | 10423777 |
| differential production of proinflammatory cytokines in the pig lung during different respiratory virus infections: correlations with pathogenicity. | the acute stages of infection with swine influenza virus (siv), porcine respiratory coronavirus (prcv) and porcine reproductive-respiratory syndrome virus (prrsv) were shown to differ in terms of clinical and lung inflammatory effects and proinflammatory cytokine profiles in bronchoalveolar lavage (bal) fluids. caesarian-derived colostrum-deprived pigs were inoculated intratracheally with one of the three viruses. siv infection was followed within 1 day post inoculation (d pi) by characteristic ... | 1999 | 10425240 |
| recombination between north american strains of porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv), a recently discovered arterivirus swine pathogen, was shown to undergo homologous recombination. co-infection of ma-104 cells with two culture-adapted north american prrsv strains resulted in recombinant viral particles containing chimeric orf 3 and orf 4 proteins. nucleotide sequence analysis of cloned recombinant pcr products, encompassing 1182 bases of the 15.4 kb viral genome, revealed six independent recombination events. recombin ... | 1999 | 10426212 |
| ifn gamma inhibits porcine reproductive and respiratory syndrome virus replication in macrophages. | this study reports the effect of ifn gamma on the replication of porcine reproductive and respiratory syndrome virus (prrsv) in macrophages. pretreatment with ifn gamma profoundly affected prrsv replication in porcine macrophages evaluated by reduction in titer and percentage of positive cells. the effect of ifn gamma on prrsv replication was both dose-dependent and related to the time of exposure. the mechanism of action was not due to blocking virus attachment. the inhibitory effect on prrsv r ... | 1999 | 10446652 |
| evaluation of protective immunity in gilts inoculated with the nadc-8 isolate of porcine reproductive and respiratory syndrome virus (prrsv) and challenge-exposed with an antigenically distinct prrsv isolate. | to determine whether intrauterine inoculation of porcine reproductive and respiratory syndrome virus (prrsv) interferes with conception and whether exposure to one strain of prrsv provides protection against challenge-exposure (ce) with homologous or heterologous strains of prrsv. | 1999 | 10451216 |
| molecular responses of macrophages to porcine reproductive and respiratory syndrome virus infection. | the detailed mechanism(s) by which porcine reproductive and respiratory syndrome virus (prrsv) impairs alveolar mo homeostasis and function remains to be elucidated. we used differential display reverse-transcription pcr (ddrt-pcr) to identify molecular genetic changes within prrsv-infected mo over a 24 h post infection period. from over 4000 ddrt-pcr amplicons examined, 19 porcine-derived ddrt-pcr products induced by prrsv were identified and cloned. northern blot analysis confirmed that four g ... | 1999 | 10489349 |
| the localization of porcine reproductive and respiratory syndrome virus nucleocapsid protein to the nucleolus of infected cells and identification of a potential nucleolar localization signal sequence. | the nucleocapsid (n) protein of porcine reproductive and respiratory syndrome virus (prrsv) possesses two regions in the n-terminal half of the protein that are enriched in basic amino acids. presumably, these basic regions are important for packaging the rna genome within the nucleocapsid of the virus. the psort computer program identified the same regions as nuclear localization signal (nls) sequence motifs. n protein localization to the nucleus of infected marc-145 and porcine pulmonary macro ... | 1999 | 10500278 |
| analysis of cellular immune response in pigs recovered from porcine respiratory and reproductive syndrome infection. | the cellular immune response to a european isolate of porcine reproductive and respiratory syndrome (prrs) virus in animals recovered from the experimental infection has been studied in vitro. peripheral blood mononuclear cells (pbmc) from these pigs proliferated specifically when they were stimulated with prrs virus. this response was not detectable until 4 weeks after inoculation and remained for more than 3 months. addition of blocking monoclonal antibodies to the cultures showed that this pr ... | 1999 | 10500281 |
| antibody and cellular immune responses of swine following immunisation with plasmid dna encoding the prrs virus orf's 4, 5, 6 and 7. | the objectives of this study was to investigate the role of dna vaccines in the generation of an immune response and that elicited against individually encoded proteins of prrsv. the genomic regions encoding orf s 4, 5, 6 and 7 of the prrs virus vaccine strain were cloned into the mammalian expression vector pc dna 3.1 (+). inoculations with the recombinant plasmids resulted in detection of prrs virus-specific antibodies in 71 per cent of the immunized animals by elisa, virus neutralization and/ ... | 1999 | 10502493 |
| elevated serum haptoglobin in pigs infected with porcine reproductive and respiratory syndrome virus. | we examined the two acute phase proteins, alpha (alpha)-1 acid glycoprotein (agp) and haptoglobin (hp), in serum of pigs following experimental porcine reproductive and respiratory syndrome (prrs) virus infection. increased levels of serum hp, but not agp, were observed from 7 to 21 days post-inoculation in the infected pigs. furthermore, serum il-6 increased in the infected pigs, but tnf-alpha did not. the increase of serum il-6 in pigs following prrs virus infection may induce production of hp ... | 1999 | 10507295 |
| heterologous challenge with porcine reproductive and respiratory syndrome (prrs) vaccine virus: no evidence of reactivation of previous european-type prrs virus infection. | in denmark, a porcine reproductive and respiratory syndrome virus (prrsv) control programme, comprising vaccination of seropositive herds with a live american type prrsv vaccine, was started in 1996. in several of these herds, spread of vaccine virus from vaccinated 3-18 week old pigs to non-vaccinated sows was demonstrated by the isolation of vaccine virus from fetuses and stillborn piglets. surprisingly, sows infected with the american type vaccine strain consistently exhibited significantly s ... | 1999 | 10510038 |
| minimal residues of porcine reproductive and respiratory syndrome virus in pig carcases and boar semen. | porcine reproductive and respiratory syndrome (prrs) is a highly contagious disease that affects pigs of all ages worldwide. one of the key features of prrs pathogenesis is the prolonged viremia in which the virus coexists with antibody. prolonged viremia raises the concern that porcine products and boar semen may be contaminated by residues of the prrs virus serving as vehicles for spreading of the virus. to answer this question, we sampled blood, muscles and viscera organs from market pigs sla ... | 1999 | 10518317 |
| [analysis of survey data about the effect of vaccination of sows against blue pig abortion (prrs) in the netherlands]. | questionnaires were used to collect information on the experience of pig breeders with the vaccination of sows against prrs. there was a 1-year interval between the two questionnaires. sixty-two pig breeders returned the first questionnaire and 36 returned the second questionnaire. before they started vaccination, 61% of the pig breeders sent samples to the laboratory of the animal health service for investigation. at least one blood sample was positive for prrs antibodies, but prrs virus was no ... | 1999 | 10522349 |
| does porcine reproductive and respiratory syndrome virus potentiate classical swine fever virus infection in weaner pigs? | fifteen 6-week-old crossbred weaners weighing about 12 kg each were randomly divided into three groups of five animals each. one group of pigs was inoculated first with porcine reproductive and respiratory syndrome (prrs) virus and then 3 days later with csf virus. the second group received classical swine fever (csf) virus, while the third group was inoculated with prrs virus only. the aim of the experiment was to determine whether a primary prrs virus infection influences the clinical outcome ... | 1999 | 10528545 |
| changes in macrophage and lymphocyte subpopulations of lymphoid tissues from pigs infected with the porcine reproductive and respiratory syndrome virus (prrsv). | we used an immunohistochemical method to investigate changes in macrophage and lymphocyte subpopulations in various lymphoid tissues of pigs in the acute phase of porcine reproductive and respiratory syndrome virus (prrsv) infection. the numbers of cd8+ cells and b-cells varied among lymphoid tissues after prrsv infection. in the infected pigs, numbers of cd8+ cells increased in systemic lymphoid tissues whereas numbers of b-cells increased in mucosa-associated lymphoid tissues. there was no dif ... | 1999 | 10587305 |
| effect of challenge dose and route on porcine reproductive and respiratory syndrome virus (prrsv) infection in young swine. | porcine reproductive and respiratory syndrome virus (prrsv) is perceived to be highly infectious because of the rapid spread of the virus through populations of domestic swine throughout the world. however, no information has been published on the minimum infectious dose of prrsv and the effect of challenge dose on clinical response. in this experiment, ten groups of pigs (n = 3 per group) were inoculated with one of five different quantities (10(1)-10(5) fluorescent foci units per millilitre) o ... | 1999 | 10596410 |
| field evaluation of a live vaccine against porcine reproductive and respiratory syndrome in fattening pigs. | a live vaccine based on a european isolate of porcine reproductive and respiratory syndrome virus (porcilis prrs) was tested in this study in order to determine the protection of fattening pigs against the respiratory form of the syndrome under field conditions. ten thousand pigs in an infected farm were vaccinated against prrs virus at the age of 6 weeks and were compared with non-vaccinated pigs with respect to their health status, mortality, performance parameters (average daily gain, average ... | 1999 | 10605370 |
| porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. | porcine reproductive and respiratory syndrome virus (prrsv) is a recently described arterivirus responsible for disease in swine worldwide. comparative sequence analysis of 3'-terminal structural genes of the single-stranded rna viral genome revealed the presence of two genotypic classes of prrsv, represented by the prototype north american and european strains, vr-2332 and lelystad virus (lv), respectively. to better understand the evolution and pathogenicity of prrsv, we obtained the 12,066-ba ... | 1999 | 9847330 |
| examination of the selective pressures on a live prrs vaccine virus. | we determined the orf5 and 7 sequences of 20 pathogenic revertants of a live prrsv vaccine. the sequence analysis confirmed all 20 isolates to be of vaccine origin. having established that clonal introduction of american (vaccine) prrs virus had occurred in denmark, we could perform analysis of the selective pressure this attenuated virus had experienced during reversion. an analysis of nucleotide mutations showed a similar rate of mutations in the two genes (orf5 and 7). however, non-synonymous ... | 1999 | 10664392 |
| effects of porcine reproductive and respiratory syndrome virus (isolate tw91) on porcine alveolar macrophages in vitro. | to verify the role of porcine reproductive and respiratory syndrome virus (prrsv) infection on pulmonary defense mechanisms, alterations in the viability, morphology, and various functions of porcine alveolar macrophages (ams) were evaluated in vitro for 2-72 h after exposure to a taiwan isolate, tw91, at a multiplicity of infection (moi) of 0.1. a low but constant rate of infection, around 5%, was seen in ams from the prrsv-infected group throughout the study. when compared with a mock-infected ... | 2000 | 10665530 |
| effects of chlorine, iodine, and quaternary ammonium compound disinfectants on several exotic disease viruses. | the effects of three representative disinfectants, chlorine (sodium hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium compound (didecyldimethylammonium chloride), on several exotic disease viruses were examined. the viruses used were four enveloped viruses (vesicular stomatitis virus, african swine fever virus, equine viral arteritis virus, and porcine reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine vesicular disease virus (svdv) ... | 2000 | 10676896 |
| experimental reinfection with homologous porcine reproductive and respiratory syndrome virus in spf pigs. | the present examination was conducted to determine if the pigs infected with one strain of porcine reproductive and respiratory syndrome virus (prrsv) would be protected against a subsequent homologous virus challenge. sixteen 4-week-old spf pigs were assigned to 2 experimental groups a and b. the pigs in group a were inoculated with 10(6.5) tcid50 of prrsv by intranasal route. on 77 days post-inoculation (pi), pigs in groups a and b were similarly inoculated with same virus. after the secondary ... | 2000 | 10676900 |
| identification of porcine circovirus in tissues of pigs with porcine dermatitis and nephropathy syndrome. | thirty-three pigs affected by porcine dermatitis and nephropathy syndrome, 30 from spain and three from the usa, were investigated in order to detect porcine circovirus (pcv) in their tissues. a standard in situ hybridisation technique using a specific dna 317-bp probe based on a well-conserved sequence of pcv (which recognises both pcv-1 and pcv-2) was applied to formalin-fixed, paraffin-embedded tissues. twenty-eight of the 30 spanish pigs and all three american pigs had pcv in at least one ti ... | 2000 | 10678809 |
| simultaneous serological evidence of actinobacillus pleuropneumoniae, prrs, aujeszky's disease and influenza viruses in spanish finishing pigs. | a total of 198 pigs with tachypnoea and temperature >/= 40 degrees c were selected on a spanish finishing unit, and their sera were examined for antibodies to actinobacillus pleuropneumoniae (app), porcine reproductive and respiratory syndrome virus (prrsv), aujeszky' disease virus (adv), and swine influenza virus (siv). eighty-nine point nine per cent of the pigs were seropositive to app, 88.6 per cent to prrs, 73.0 per cent to adv, and 30.6 per cent to siv. thirty-one pigs (15.6 per cent) were ... | 2000 | 10684752 |
| diagnostic performance of a reverse transcription-polymerase chain reaction test for porcine reproductive and respiratory syndrome virus. | 2000 | 10690783 |