identification of heat-dissociable rna complexes in two porcine coronaviruses. 1975170536
vaccination experiments against transmissible gastroenteritis (tge) of swine. iv. the titre and persistence of virus-neutralizing antibodies in the sera of sows vaccinated once or twice at different intervals. 1975171936
chromatographic separation of gram quantities of immunoglobulins from porcine colostrium against transmissible gastroenteritis virus.similar immunoglobulin (ig) classes were obtained from porcine colodtral whey by either column or batch chromatographic procedures; a stepwise buffer elution technique was used. specific transmissible gastroenteritis virus neutralizing antibody was found in the 4 major fractions eluted comprising of igg1, igg2, iga, and igm. the igg1, and igg2 were essentially homogeneous, and the iga- and igm-rich fractions had to be recycled several times through sephadex g-200 to obtain pure iga and igm that ...1976180183
the isolation of reovirus-like agents (rota-viruses) from acute gastroenteritis of piglets.isolations of reovirus-like agents (rotaviruses) were made from nine of 23 outbreaks of piglet diarrhoea on different farms and from both weaned and unweaned piglets. the viruses were shown to be morphologically and anti-genically similar to the rotaviruses of children and calves. gnotobiotig piglets given intranasal inoculations of five different isolates developed acute gastroenteritis, and the virus was re-isolated from the faeces or intestinal contents. the piglet virus was not adapted to re ...1976180294
transmissible gastroenteritis of swine. efficacy assay of an intramammary use vaccine.tge seronegative pregnant gilts were vaccinated by intramammary inoculations with a chemically inactivated (betapropiolactone) cell culture virus vaccine and their nursing pigs were exposed to virus at three days of age. the pig morbidity and survival rates were compared with those of pigs nursing gilts exposed orally to virulent tge virus during late gestation and also with pigs nursing non-vaccinated seronegative sows. the morbidity rates were 100%, 19% and 19%, while the survival rates were ...1976182600
immune electron microscopy of transmissible gastroenteritis virus and rotavirus (reovirus-like agent) of swine.immune electron microscopy (iem) was developed as a diagnostic aid for detecting and identifying transmissible gastroenteritis virus and rotavirus (reovirus-like agent) in fecal and intestinal contents from cases of gastroenteritis in young pigs. variables involved in use of direct iem and its sensitivity were determined. aggregates of virus coated with specific antibody were seen in virus samples mixed with homologous convalescent antiserum, but not in control samples containing preexposure ser ...1977189646
further studies on human enteric coronaviruses.comparisons were made between human enteric coronaviruses and the enteric coronaviruses of pigs and calves by negative staining. examination of human intestinal organ culture fluids at various time intervals after inoculation with the human enteric coronavirus showed increasing numbers of particles in the fluids. thin sections of the columnar epithelial cells of these explants showed a number of features consistent with the replication of known human and animal coronaviruses. virus particles fou ...1977196571
vaccination experiments against transmissible gastroenteritis (tge) of swine. v. relationship between the titre and the antigenic effect of the vaccine. 1976200132
[attempts to develop an immunoprevention for transmissible gastroenteritis (tge) in swine. ii. immunogenicity of the b1 strain following serial passages]. 1978207054
colostral iga, igg, and igm-iga fractions as fluorescent antibody for the detection of the coronavirus of transmissible gastroenteritis.colostrum from sows and gilts inoculated with virulent transmissible gastroenteritis virus was fractionated into the 3 major immunoglobulin classes, iga, igg, and igm-iga fractions, by chromatographic and gel-filtration procedures. each fraction was assayed for purity with rabbit anti-porcine serum and rabbit monospecific anti-porcine igg, anti-porcine iga, and anti-porcine igm. these analyses showed that the igg and iga fractions were pure. the igm fraction contained some iga in the polymeric f ...1978211888
virus isolation and serum antibody responses after infection of cats with transmissible gastroenteritis virus. brief report.transmissible gastroenteritis virus was administered orally to cats. no clinical disease resulted but infectious virus was isolated from faeces for up to 22 days after infection and serum antibody was detected by neutralisation and immunofluorescence tests.1979226036
antigen selection and presentation to protect against transmissible gastroenteritis coronavirus.the antigenic structure of the s glycoprotein of transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv) has been determined and correlated with the physical structure. four antigenic sites have been defined (a, b, c, and d). the sites involved in the neutralization of tgev are: a, d, and b, sites a and d being antigenically dominant for tgev neutralization in vitro. these two sites have specific properties of interest: site a is highly conserved and is present in c ...19921282756
adaptation of transmissible gastroenteritis virus to growth in non-permissive vero cells.the cpk cells derived from swine kidney were infected with the attenuated to-163 strain of transmissible gastroenteritis (tge) virus, and fused with uninfected vero cells in the presence of polyethylene glycol. repeated cocultivation of the fused cells with uninfected vero cells rendered the virus to grow in vero cells. the vero cell-adapted virus acquired the ability to infect and produce cytopathic effects in several other non-permissive cell lines of non-porcine origin. no major differences i ...19921309640
clinical and pathologic effects of oral administration of transmissible gastroenteritis vaccine to gnotobiotic pigs.pigs from 3 litters kept under gnotobiotic conditions were inoculated orally with virulent transmissible gastroenteritis (tge) virus, a tge vaccine, or hank's balanced salt solution at 2 days of age and then euthanatized at intervals ranging from 1 to 7 days after inoculation. pigs exposed to the vaccine had clinical evidence of diarrhea and weakness. lesions resembling those of tge were revealed grossly, microscopically, and by scanning electron microscopy. viral antigen was seen in intestinal ...19921311537
pathogenicity and antigen detection of the nouzilly strain of transmissible gastroenteritis coronavirus, in 1-week-old piglets.we compared the pathogenicity and the sites of multiplication of the attenuated nouzilly strain, with the highly passaged purdue-115 and the virulent gep ii strains of transmissible gastroenteritis (tge) coronavirus, in 1-week-old weaned piglets. the immunohistochemical peroxidase technique, with an antiviral nucleoprotein monoclonal antibody, was used for the localization of the multiplication sites, in the intestine and other organs. the gep ii and the purdue-115 strains, administered orally t ...19921313460
seroconversion of pigs in contact with dogs exposed to canine order to determine if canine coronavirus (ccv) could be transmitted to pigs, two dogs were inoculated orally with virulent ccv. after 24 h, the dogs were moved to an isolation room that contained three three-day-old pigs. a wire mesh fence, allowing close contact between the animals, separated the dogs from the pigs. the dogs and pigs were observed for 14 days for clinical signs of disease. samples of blood were obtained from dogs and pigs immediately before the dogs were inoculated with viru ...19921316800
antigenic variant of swine influenza virus causing proliferative and necrotizing pneumonia in pigs.a new antigenic variant of swine influenza virus was isolated from the lungs of pigs experiencing respiratory problems in 7 different swine herds in quebec. pigs of different ages were affected, and the main clinical signs were fever, dyspnea, and abdominal respiration. coughing was not a constant finding of the syndrome. at necropsy, macroscopic lesions included the overall appearance of pale animals, general lymphadenopathy, hepatic congestion, and consolidation of the lungs. histopathologic f ...19921333815
a seroepizootiologic study of five viruses in a swine-evaluation station.this serologic study was done to gain information on the spread, maintenance, and effect upon performance of five porcine viruses. blood samples were taken from two groups of 8- to 11-week-old pigs from a large number of indiana swine herds in a performance-testing station 1 week after entry, 7 weeks after entry (one group only), and at slaughter. the sera were tested by indirect fluorescent antibody tests for antibodies to transmissible gastroenteritis virus (tgev), swine influenza virus (siv), ...1979230762
lymphocyte proliferative response to viral antigen in pigs infected with transmissible gastroenteritis virus.development and sequence of lymphocytes reactive to viral antigen in peyer's patches, mesenteric lymph nodes, spleen, and peripheral blood of pigs orally inoculated with transmissible gastroenteritis virus were investigated by a lymphocyte proliferative assay. lymphocytes reactive to the viral antigen were first detected in all the tissues of pigs tested on postinoculation day 7. thereafter, they increased in proliferative reactivity and reached a maximal amount on postinoculation days 10 to 14. ...1979217826
effects of ambient temperatures on induction of transmissible gastroenteritis in feeder pigs.experiments were carried out to investigate the effects of ambient temperatures on the induction of transmissible gastroenteritis in feeder pigs 2 to 3 months old. pigs maintained at a high temperature (30 +/- 2 degrees c) and exposed to the virulent transmissible gastroenteritis virus did not show clinical signs of the disease during their maintenance at the high temperature. on the other hand, a sudden decrease in the ambient temperature, either before or after virus inoculation, induced sever ...1978213387
small plaque variant transmissible gastroenteritis virus.a small plaque (sp) variant transmissible gastroenteritis (tge) virus strain that may be useful in the control of tge in swine has been developed and tested. this strain was derived from a persistently infected swine leukocyte cell line originally infected with a virulent tge virus. the sp viral strain was avirulent for 3-day-old susceptible pigs and pregnant gilts. the sp virus elicited protective antibody when inoculated into pregnant gilts oral/intranasally, or intramammarily, or by both of t ...1978212409
differentiation between transmissible gastroenteritis virus and porcine respiratory coronavirus using a cdna probe.a plasmid, pg3bs, containing a cdna clone from the 5' coding region of the peplomer glycoprotein gene appears to be specific for enteric transmissible gastroenteritis virus (tgev) strains and for live-attenuated tgev vaccines. this cdna probe is used to differentiate porcine respiratory coronavirus (prcv) isolates from tgev field and vaccine strains by a slot blot hybridization assay. probe pg3bs also hybridizes to canine coronavirus (ccv) rna but does not hybridize to antigenically related feli ...19911645595
leukocyte migration-inhibition procedure for transmissible gastroenteritis viral antigens.swine exposed to transmissible gastroenteritis viral antigens developed humoral and cell-mediated immunity. migration of leukocytes from exposed swine was inhibited in the presence of the sensitizing antigens, whereas migration of leukocytes from nonexposed swine was not inhibited in the presense of these same antigens. in virus-neutralization-positive animals, it was not possible to correlate degree of inhibition with virus-neutralization titer. inhibition was observed 7 days after exposure and ...1977199095
prevalence of pseudorabies virus infection and associated infections in six large swine herds in illinois.sera were collected from 6 large farrow-to-finish swine herds infected with pseudorabies virus (prv) in illinois. all herds were participating in the large herd cleanup study, a usda-initiated project to evaluate the feasibility of eradicating pseudorabies from large farms (greater than 400 sows) by use of a combination of vaccination and management changes. herd size ranged between 425 and 1,500 breeding females. between april and july 1990, sera for measurement of prv antibodies were obtained ...19911651912
neutralization of a transmissible gastroenteritis virus of swine by colostral antibodies elicited by intestine and cell culture-propagated virus.cross-protection studies of gilts exposed to 4 transmissible gastroenteritis viruses--ilinois (field strain), miller-3, miller low passage (m-lp), and miller high passage (m-hp) tissue culture-adapted--indicated that only the gilt vaccinated with illinois strain was protected, along with its newborn pigs, against challenge exposure with field virus. similar results were obtained when the 4 viruses were incubated in vitro with colostrum from each of the 4 vaccinated gilts and subsequently used to ...1976183573
evaluation of 6-azauridine and 5-iododeoxyuridine in the treatment of experimental viral infections.the potential antiviral activity of 6-azauridine and 5-iododeoxyuridine was evaluated in a coordinated study at five institutions. experimental models in five species, the mouse, rabbit, swine, cat, and ferret, were established with use of 10 viruses: herpesvirus hominis types 1 and 2, murine cytomegalovirus, vaccinia virus, shope fibroma virus, transmissible gastroenteritis virus, swine influenza virus, feline viral rhinotracheitis virus, feline panleukopenia virus, and ferret distemper virus. ...1976180189
recovery of transmissible gastroenteritis virus from chronically infected experimental pigs.transmissible gastroenteritis (tge) virus was reisolated from pulmonary and intestinal tissues from 6 of 9 chronically infected experimental pigs (principals) necropsied 30 to 104 days after inoculation. tissue homogenates (lung and small intestine) from the principals were prepared and inoculated into 3- to 5-day-old gnotobiotic pigs. the virus reisolated from the tissue homogenates produced a milder disease on 1st passage and a more severe disease on 2nd passage. the chronically infected exper ...1975171980
viral susceptibility of a cell line derived from the pig oviduct.seventeen of 24 rna viruses and eight of nine dna viruses replicated in a cell line derived from a pig fallopian tube. the following rna viruses grew poorly in it: the virus of transmissible gastroenteritis of pig and the swine-influenza, sendai and bovine para-influenza type 3 viruses. among other rna viruses an untyped swine para-myxovirus and some picornaviruses, rhabdoviruses and togaviruses attained high titers and produced an extensive cytopathic effect. among the dna viruses a porcine ade ...1975169971
outbreaks in quebec pig farms of respiratory and reproductive problems associated with encephalomyocarditis virus.encephalomyocarditis virus (emcv) was isolated from tissues of aborted fetuses and weaned and suckling piglets from 4 different pig farms in quebec. the farms were experiencing reproductive failure in sows of different parities concomitant to respiratory problems in suckling and postweaning piglets. at necropsy, gross lesions were confined to the lung and consisted of pulmonary congestion and edema of various degrees. lesions of multifocal interstitial to proliferative pneumonia were found in th ...19911662074
enzyme immunofiltration assay for measurement of antibodies to transmissible gastroenteritis virus of swine: comparison with enzyme immunosorbence assay, serum neutralization, and indirect immunofluorescent antibody techniques. 19911662083
antigenic relationship of the feline infections peritonitis virus to coronaviruses of other species.utilizing the direct and indirect fluorescent antibody procedure, the antigenic relationship of the feline infectious peritonitis virus (fipv) to 7 other human and animal coronaviruses was studied. fipv was found to be closely related to transmissible gastroenteritis virus (tgev) of swine. transmissible gastroenteritis virus and fipv were in turn antigenically related to human coronavirus 229e (hcv-229e) and canine coronavirus (ccv). an interesting finding in the study was that the 8 coronavirus ...197881044
transmissible gastroenteritis virus antibody production in vitro by porcine peripheral blood leukocytes.the purpose of this study was to demonstrate the in vitro production of transmissible gastroenteritis virus (tgev)-specific antibodies by peripheral blood leukocytes (pbl) harvested from piglets infected with tgev. piglets were infected with the virulent purdue strain of tgev and at intervals postinfection their pbl were cultivated in the presence of tgev antigen, control antigen or pokeweed mitogen (pwm). the culture supernatants were tested for tgev antibodies by a fixed cell enzyme immunoassa ...19921317248
efficacy of antiserum produced in goats and pigs to passively protect piglets against virulent transmissible gastroenteritis virus.the protective effect of sera produced in swine and goats exposed to virulent transmissible gastroenteritis virus (tgev) or modified-live tgev was tested in hysterectomy-derived, colostrum-deprived three-day-old pigs. pigs were given serum with their daily ration of milk, and their immunity to virulent tgev was determined. the pigs were observed for ten days for clinical signs of tgev infection. one of nine pigs receiving goat serum was protected whereas all three pigs receiving three doses of s ...19921317247
immunoglobulin classes of antibodies in milk of swine after intranasal exposure to pseudorabies virus or transmissible gastroenteritis virus.experiments were conducted to evaluate whether infection of the respiratory tract of pregnant swine with pseudorabies (pr) virus would induce the secretion of immunoglobulin a (iga) antibodies in their milk as was observed after enteric infection with transmissible gastroenteritis (tge) virus. the immune response of sows to pr virus inoculated intranasally and to tge virus inoculated orally/intranasally or via a natural infection was studied. emphasis was placed upon titers and ig classes of pr ...1977197014
the detection of transmissible gastroenteritis viral antibodies by immunodiffusion.precipitating antibodies against transmissible gastroenteritis viral antigens were detected by the immunodiffusion test in two transmissible gastroenteritis viral hyperimmune antisera and in antiserum prepared against haemagglutinating encephalomyelitis virus but not in sera from several species of normal animals, in antisera prepared against a variety of othet viruses and bacteria or sera from swine with bacterial enteritis. when the immunodiffusion test was compared with the virus neutralizati ...1976187295
leukocyte-aggregation assay for transmissible gastroenteritis of in vitro leukocyte-aggregation assay was developed to detect the exposure of swine to transmissible gastroenteritis virus. leukocytes in heparinized blood samples aggregated when mixed with test antigen prepared from transmissible gastroenteritis-infected swine testicle cell cultures. twenty-two of 23 swine exposed 3 days or more were positive or suspects in the assay; 6 nonexposed swine were negative. aggregation was shown as early as 3 days postexposure in 1 sow and persisted for as long as ...1976187089
antigenic variation among transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus strains detected with monoclonal antibodies to the s protein of tgev.five nonneutralizing monoclonal antibodies (mab) generated to the virulent miller strain of transmissible gastroenteritis virus (tgev) and specific for the s protein were characterized. competition assays between purified and biotinylated mab indicated that mab 75b10 and 8g11 mapped near a new subsite, designated v and 2 mab, 44c11 and 45a8, mapped to a previously designated subsite d. a fifth mab mapped between subsites v and e. these mab were tested with 3 previously characterized mab to subsi ...19921379786
aminopeptidase n is a major receptor for the entero-pathogenic coronavirus tgev.coronaviruses, like many animal viruses, are characterized by a restricted host range and tissue tropism. transmissible gastroenteritis virus (tgev), a major pathogen causing a fatal diarrhoea in newborn pig, replicates selectively in the differentiated enterocytes covering the villi of the small intestine. to investigate the molecular determinants of the infection, we characterized the surface molecule used by the virus for binding and entry into host cells. here we report that aminopeptidase n ...19921350661
interferon induction in porcine leukocytes with transmissible gastroenteritis virus.leukocytes were harvested from the peripheral blood, mesenteric lymph node and small intestinal lamina propria from groups of three piglets before, and 1, 2 and 3 weeks after infection with virulent transmissible gastroenteritis virus (tgev) at 2 weeks of age. the donor piglets developed clinical signs of transmissible gastroenteritis which persisted for up to 3 days, and they developed peak serum titres of tgev-neutralizing antibodies 2 weeks post-infection. the leukocytes were cultured in the ...19921345591
genomic organization and expression of the 3' end of the canine and feline enteric coronaviruses.the genomic organization at the 3' end of canine coronavirus (ccv) and feline enteric coronavirus (fecv) was determined by sequence analysis and compared to that of feline infectious peritonitis virus (fipv) and transmissible gastroenteritis virus (tgev) of swine. comparison of the latter two has previously revealed an extra open reading frame (orf) at the 3' end of the fipv genome, lacking in tgev, which is currently designated orf 6b. both ccv and fecv possess 6b-related orfs at the 3' ends of ...19921329312
intestinal permeability in piglets during transmissible gastroenteritis.macromolecular permeability of the small intestine was tested in seven three-week-old piglets infected with porcine transmissible gastroenteritis virus (tge-strain miller). fourteen hours after the infection, the piglets showed loss of appetite and a profuse diarrhoea. in some animals vomiting occurred somewhat earlier. macromolecular permeability was tested morphologically by injecting horseradish peroxidase (mw = 40,000 da) into the jejunal lumen just distally to the treitz' ligament in two pi ...19911830439
differentiation of transmissible gastroenteritis virus from porcine respiratory coronavirus and other antigenically related coronaviruses by using cdna probes specific for the 5' region of the s glycoprotein gene.two cdna clones prepared from the virulent miller strain of transmissible gastroenteritis virus (tgev) were identified, and their nucleotide sequences were determined. the clones were nonoverlapping and located in the 5' region of the s glycoprotein gene. their nucleotide and predicted amino acid sequences were compared with published sequences of the attenuated purdue strain of tgev and feline infectious peritonitis virus (fipv). tgev clone pe21 contained 381 bp of the s glycoprotein gene and h ...19911847152
transmissible gastroenteritis coronavirus: surface antigens induced by virulent and attenuated strains.three strains of the transmissible gastroenteritis virus (tgev) possessing different degrees of pathogenicity for piglets were examined for their capacity to express m and s glycoproteins on the infected cell surface using a microwell immunoperoxidase test. these two viral glycoproteins were easily detected on the plasma membrane of 0.1% paraformaldehyde-fixed swine testis (st) or pig kidney (rp.d) cells which were infected with high-passaged purdue-115 and low-passaged d-52 strains and a high-p ...19921329166
effect of fixation on the detection of transmissible gastroenteritis coronavirus antigens by the fixed-cell immunoperoxidase technique.the effect of various fixatives and detergents on the in vitro detection of the viral determinants which are expressed in swine testis cells infected with the transmissible gastroenteritis coronavirus (tgev) was studied using a microwell immunoperoxidase technique. when compared with glutaraldehyde and formaldehyde, 0.1% paraformaldehyde was found to be the fixative of choice for the detection of these determinants on the membranes of infected cells. among dehydrating fixatives, 80% acetone or a ...19921328393
genetic evolution and tropism of transmissible gastroenteritis coronaviruses.transmissible gastroenteritis virus (tgev) is an enteropathogenic coronavirus isolated for the first time in 1946. nonenteropathogenic porcine respiratory coronaviruses (prcvs) have been derived from tgev. the genetic relationship among six european prcvs and five coronaviruses of the tgev antigenic cluster has been determined based on their rna sequences. the s protein of six prcvs have an identical deletion of 224 amino acids starting at position 21. the deleted area includes the antigenic sit ...19921326823
characterization and reactivity of monoclonal antibodies to the miller strain of transmissible gastroenteritis virus of swine.hybridomas secreting monoclonal (mab) to transmissible gastroenteritis virus (tgev) were produced by fusion of sp2/0 myeloma cells and splenic lymphocytes of balb/c mice immunized with the virulent cell-passaged miller strain of tgev. the mab secreted by these hybridomas were partially characterized; 4 of them (ma4, ma5, mh11, mb2) had high-neutralization titer for tgev. the remaining 7 (mc6, md9, me5, mg5, mf2, me9, mg7) did not neutralize tgev at 1:25 dilution. all 4 neutralizing and 2 of the ...19901689128
antigenic homology among coronaviruses related to transmissible gastroenteritis virus.the antigenic homology of 26 coronavirus isolates, of which 22 were antigenically related to transmissible gastroenteritis virus (tgev), was determined with 42 monoclonal antibodies. type, group, and interspecies specific epitopes were defined. two group specific mabs distinguished the enteric tgev isolates from the respiratory variants. an antigenic subsite involved in neutralization was conserved in porcine, feline, and canine coronavirus. the classification of the human coronavirus 229e in a ...19901689525
comparison of the antibody response to transmissible gastroenteritis virus and porcine respiratory coronavirus, using monoclonal antibodies to antigenic sites a and x of the s glycoprotein.pigs were inoculated with various strains of transmissible gastroenteritis virus (tgev) or with porcine respiratory coronavirus (prcv), and antigenic site-specific antibody responses were compared. a blocking-elisa was used to study to what extent antibodies in convalescent sera interfered with the binding of monoclonal antibodies (mab) 57.16 or 57.110 to the attenuated tgev/purdue virus. monoclonal antibody 57.16 is directed against the a site on the peplomer, neutralizes virus, and recognizes ...19921315491
single amino acid changes in the viral glycoprotein m affect induction of alpha interferon by the coronavirus transmissible gastroenteritis virus.transmissible gastroenteritis virus, an enteropathogenic coronavirus of swine, is a potent inducer of alpha interferon (ifn-alpha) both in vitro and in vivo. previous studies have shown that virus-infected fixed cells or viral suspensions were able to induce an early and strong ifn-alpha synthesis by naive lymphocytes. two monoclonal antibodies directed against the viral membrane glycoprotein m (29,000; formerly e1) were found to markedly inhibit virus-induced ifn production, thus assigning to m ...19921309909
viral gastroenteritis: recent progress, remaining problems.infants and young children are particularly susceptible to a recently identified viral enteritis which is highly contagious and seems both common and universal. in this disease, virus invades the upper intestinal epithelium, causing acute diarrhoea with early fever and vomiting. we studied a similar disease in pigs, infecting three-week-old animals with transmissible gastroenteritis virus (tge), which also invades the upper intestinal epithelium. in this model, diarrhoea is massive 16-40 hours a ...19761049555
epitope specificity of protective lactogenic immunity against swine transmissible gastroenteritis virus.the epitope specificity of the protective immune response against swine transmissible gastroenteritis (tge) has been investigated by using circulating and secretory antibodies. this study was carried out with sows vaccinated with tgev or the antigenically related porcine respiratory coronavirus (prcv). tgev vaccination of sows resulted in greater lactogenic protection of suckling piglets against tgev challenge and a higher secretory immune response than prcv vaccination did. these differences in ...19921383566
effect of concentration and source of sulfate on nursery pig performance and health.the effect of sulfate in drinking water at concentrations of 600, 1,200, and 1,800 mg/l on nursery pig performance and health was evaluated over 28 days on 415 weaned pigs. sodium sulfate and magnesium sulfate were evaluated in combination at concentrations of 600, 1,200, and 1,800 mg/l, and independently at concentrations of 600 and 1,800 mg/l in the drinking water. seven treatment groups and 1 control group were evaluated for mean gain, feed consumption, water consumption, feed conversion, pre ...19921429159
evidence for a porcine respiratory coronavirus, antigenically similar to transmissible gastroenteritis virus, in the united states.a respiratory variant of transmissible gastroenteritis virus (tgev), designated prcv-ind/89, was isolated from a swine breeding stock herd in indiana. the virus was readily isolated from nasal swabs of pigs of different ages and induced cytopathology on primary porcine kidney cells and and on a swine testicular (st) cell line. an 8-week-old pig infected oral/nasally with the respiratory variant and a contact pig showed no signs of respiratory or enteric disease. these pigs did not shed virus in ...19901965638
an elisa for detection of antibodies against porcine epidemic diarrhoea virus (pedv) based on the specific solubility of the viral surface glycoprotein.viral proteins of porcine epidemic diarrhoea virus (pedv) were extracted from the cytoplasm of infected vero cells using hypotonic conditions and a non-ionic detergent. both the ph and the nacl concentration of the extraction buffer were varied in attempts to increase the solubility of the virion spike glycoproteins (s-protein) and of the nucleocapsid proteins (n-protein). monoclonal antibodies, hyperimmune sera and convalescent pig sera were used to identify and monitor these proteins by immuno ...19921441196
serological studies of transmissible gastroenteritis in great britain, using a competitive elisa.a competitive elisa which differentiates between transmissible gastroenteritis virus (tgev) and porcine respiratory coronavirus (prcv) was used to detect non-neutralising antibodies to the peplomer protein of tgev in porcine sera. the test was shown to be tgev specific, having a relative specificity of 100 per cent, and to have a relative sensitivity of 94.9 per cent when compared with the virus neutralisation test. the prevalence of tgev in great britain is low; only 0.6 per cent of sows sample ...19911651028
antiviral activity against transmissible gastroenteritis virus, and cytotoxicity, of natural porcine interferons alpha and beta.porcine interferon (poifn)-alpha prepared in primed peripheral blood leukocyte cultures induced with newcastle disease virus and poifn-beta from pk-15 cell cultures induced with polyinosinic:polycytidylic acid were partially purified by precipitation with potassium thiocyanate and anion exchange chromatography. mean purification factors in terms of units of poifn per mg of protein, of 37 and 12 were obtained for poifn-alpha and poifn-beta respectively. in yield reduction assays in swine testis a ...19911653103
the effect of interferon induction in newborn piglets on the humoral immune response to oral vaccination with transmissible gastroenteritis virus.groups of newborn piglets were vaccinated orally with a modified live transmissible gastroenteritis (tge) virus vaccine at 3 days and 13 days of age, and treated with the synthetic interferon (ifn) inducer polyinosinic:polycytidylic acid (poly iclc) at 2, 3 or 4 days of age. control groups consisted of piglets which were vaccinated but not treated with poly iclc, as well as piglets which were treated with poly iclc but not vaccinated. significantly higher mean ifn titres were produced in respons ...19901692649
expression of swine transmissible gastroenteritis virus envelope antigens on the surface of infected cells: epitopes externally exposed.the peplomer protein (s) and the transmembrane protein (m) of transmissible gastroenteritis virus (tgev) of swine were identified by iodination and serologically on the surface of infected cells. of a total of 4 monoclonal antibodies (mab) directed against four antigenic sites of s protein (correa et al., 1988), 3 specific for sites a, b and d attached to the plasma membrane of infected cells, as disclosed by indirect immunofluorescence and by complement-mediated cytolysis. four of the mabs assa ...19901697441
characterization of monoclonal antibodies against feline infectious peritonitis virus type ii and antigenic relationship between feline, porcine, and canine monoclonal antibodies (mabs) with neutralizing activity against feline infectious peritonitis virus (fipv) strain 79-1149 (type ii) were prepared. when the polypeptide specificity recognized by these monoclonal antibodies (mabs) was investigated by western immunoblotting, all of the mabs reacted with peplomer glycoprotein (s) of the virus. by competitive binding assay these mabs were found to recognize at least 3 different epitopes. the reactivity of these mabs with 6 viruses classified as ...19911706593
antigenic analysis of feline coronaviruses with monoclonal antibodies (mabs): preparation of mabs which discriminate between fipv strain 79-1146 and fecv strain 79-1683.we prepared 31 monoclonal antibodies (mabs) against either fipv strain 79-1146 or fecv strain 79-1683, and tested them for reactivity with various coronaviruses by indirect fluorescent antibody assay (ifa). sixteen mabs which reacted with all of the 11 strains of feline coronaviruses, also reacted with canine coronavirus (ccv) and transmissible gastroenteritis virus (tgev). in many of them, the polypeptide specificity was the recognition of transmembrane (e1) protein of the virus. we succeeded i ...19911653482
a capture-enzyme immunoassay for rapid diagnosis of transmissible gastroenteritis virus.two enzyme immunoassays (eia) were developed for the detection of swine transmissible gastroenteritis virus (tgev) antigens. the 2 eias used the same detecting system, a monoclonal antibody conjugated to horseradish peroxidase, but used different capture systems including a monoclonal antibody (m-eia) or a polyclonal antibody (p-eia). the eias were compared with the fluorescent antibody test (fat) and electron microscopy (em) for the detection of tgev in intestinal samples of experimentally inoc ...19911654131
proteins specified by swine transmissible gastroenteritis virus: identification of non-structural proteins by two-dimensional electrophoresis.four virus-induced non-structural proteins with apparent molecular weights of 11-14 kilodaltons (kda) were identified by two-dimensional electrophoresis in cells infected by tgev. differences in the number of non-structural proteins were observed among virulent and attenuated tgev strains as well as with two antigenically related feline and canine coronaviruses.19911662051
fixed-cell immunoperoxidase technique for the study of surface antigens induced by the coronavirus of transmissible gastroenteritis (tgev).an immunoperoxidase technique performed on the tgev-infected cells was developed for detection of virus-induced antigens. the presence of m antigen of tgev on the surface of infected cells was demonstrated by this technique. this finding is in contrast to the m protein of murine hepatitis coronavirus which migrates to the golgi apparatus but is not transported to the plasma membrane. the time course of appearance m and s antigens on the surface of tgev-infected cell can be studied by this techni ...19911663290
histocompatible miniature pig (d/d haplotype): generation of hybridomas secreting a or m monoclonal antibody.two hypoxanthine/aminopterin/thymidine-sensitive cell sublines (l142 and l231) have been derived from independent lymphoblastoid cell lines of b lineage. after propagation for more than 100 population doublings (1 year) in culture, these cells still retained a doubling time between 19 to 20 hours, near diploïdy and relatively low (l142) and high (l231) secretion rate of m immunoglobulins. near diploid hybrid cells were easily generated with leukocytes from the spleen, the gut lamina propria or t ...19911667778
enteric coronavirus tgev: mapping of four major antigenic determinants in the amino half of peplomer protein e 2. 19901715657
infection of pigs with transmissible gastroenteritis virus from contaminated carcases.sixteen 6-month-old pigs were exposed to transmissible gastroenteritis (tge) virus by placing them in close contact with piglets infected at 1 week of age. fourteen of the older pigs were slaughtered between 1 and 5 d after exposure to infection and their carcases dressed in simulated abattoir conditions. samples of muscle, bone marrow and carcase lymph nodes were stored at -25 degrees c for at least 30 d and then homogenised and fed to groups of 1-week-old and 3-week-old pigs. four of 12 one-we ...19911850235
mechanisms of transmissible gastroenteritis coronavirus neutralization.transmissible gastroenteritis virus (tgev) was neutralized more than 10(9)-fold with antibodies of a single specificity [monoclonal antibodies (mabs)]. most of the virus was neutralized in the first 2-3 min of a reversible reaction, which was followed by a second phase with a decreased neutralization rate and, in some cases, by a persistent fraction, which was a function of the mab and of the antibody-to-virus ratio. neutralization of tgev is a specific event that requires the location of the ep ...19902164725
sequence analysis of the leader rna of two porcine coronaviruses: transmissible gastroenteritis virus and porcine respiratory coronavirus.the leader rna sequence was determined for two pig coronaviruses, transmissible gastroenteritis virus (tgev), and porcine respiratory coronavirus (prcv). primer extension, of a synthetic oligonucleotide complementary to the 5' end of the nucleoprotein gene of tgev was used to produce a single-stranded dna copy of the leader rna from the nucleoprotein mrna species from tgev and prcv, the sequences of which were determined by maxam and gilbert cleavage. northern blot analysis, using a synthetic ol ...19901962975
an elisa for the detection of serum antibodies to both transmissible gastroenteritis virus and porcine respiratory coronavirus.a competition elisa utilizing a mab directed towards a peplomer protein epitope common to tgev, prcv and related feline and canine coronaviruses is described.19911717102
detection of transmissible gastroenteritis virus using cdna probes.five cdna probes prepared from molecular clones representing genomic rna sequences of the virulent miller strain of transmissible gastroenteritis virus (tgev) were used in a dot blot hybridization assay to detect tgev in cell culture and fecal specimens. two clones (pa2 and pb4) represent nucleotide base pairs at the 3' terminus of the miller tgev genome. the other three clones represent various portions of the 5' end of the e2 gene, which codes for the major surface glycoprotein of tgev. each o ...19911848070
glycosylation is required for coronavirus tgev to induce an efficient production of ifn alpha by blood mononuclear cells.porcine peripheral blood mononuclear cells (pbmc) are induced to produce interferon alpha (ifn alpha) following in vitro exposure to coronavirus tgev (transmissible gastroenteritis virus)-infected glutaraldehyde-fixed cell monolayers or to tgev virions. in the present report, we examined the possibility that glycosylation of viral proteins could play a major role in interactions with pbmc leading to the production of ifn alpha. con a pretreatment of tgev-infected cell monolayers before fixation ...19911850168
induction of lactogenic immunity to transmissible gastroenteritis virus of swine using an attenuated coronavirus mutant able to survive in the physicochemical environment of the digestive tract.a transmissible gastroenteritis (tge) coronavirus mutant (188-sg), selected as attenuated and resistant to acidity and proteases of the digestive tract of adult pigs, was used as vaccine ("nouzilly strain") in sows to protect suckling piglets against a challenge exposure carried out with a highly virulent tgev strain. the pregnant sows were immunized once (42-49 days before farrowing) or twice (42-49 and 7-15 days before farrowing) by the oral, intramuscular or conjunctival route with the 188-sg ...19911850894
intracellular processing of the porcine coronavirus transmissible gastroenteritis virus spike protein expressed by recombinant vaccinia virus.the spike (s) protein from a virulent british field isolate of porcine transmissible gastroenteritis virus (tgev) fs772/70 was constructed from cdna and inserted into the vaccinia virus (vv) thymidine kinase gene locus under the control of the vv early/late gene p7.5k promoter. recombinant s protein was synthesized as an endo-beta-n-acetylglucosaminidase h (endo h)-sensitive glycoprotein with high mannose simple oligosaccharides (gp 190) that underwent post-translational modification to an endo ...19911850927
molecular biology of transmissible gastroenteritis virus.the causative agent (tgev) of porcine transmissible gastroenteritis belongs to the coronaviridae, a family of enveloped viruses with a positive, single-stranded rna genome. important progress has recently been made concerning the molecular biology of tgev. the research work of our group has been focused on two main aspects: genome structure and functional domains of the envelope proteins. tgev genomic rna is organised into seven regions. the sequence of six of them, i.e. the 3' most 8300 nucleot ...19902169670
oral transmission of transmissible gastroenteritis virus by muscle and lymph node from slaughtered pigs.a study was conducted in the usa to determine whether transmissible gastroenteritis (tge) virus could be transmitted from carcases of slaughtered pigs. transmissible gastroenteritis virus was transmitted to 6-day-old piglets by dosing with homogenates of muscle and lymph node collected from 500 clinically normal pigs at the time of slaughter. all piglets in 2 separately housed litters showed clinical signs of tge with 5 piglets dying within 10 d of oral dosing with homogenates. transmissible gas ...19911850981
experimental induction of diarrhoea in newly-weaned induce diarrhoea and hypovolaemia, newly-weaned conventionally bred piglets (3- to 4-weeks-old), were either given secretagogues or were inoculated with enterotoxigenic escherichia coli (etec). choleratoxin (n = 2), e. coli heat-labile enterotoxin (n = 2) or castor oil (n = 2) were given intragastrically or piglets were intraperitoneally injected with dl 5-hydroxytryptophan (n = 3). these substances induced a transient diarrhoea without clinical symptoms of dehydration. therefore, a combinati ...19911950231
residues involved in the antigenic sites of transmissible gastroenteritis coronavirus s glycoprotein.the s glycoprotein of transmissible gastroenteritis virus (tgev) has been shown to contain four major antigenic sites (a, b, c, and d). site a is the main inducer of neutralizing antibodies and has been previously subdivided into the three subsites aa, ab, and ac. the residues that contribute to these sites were localized by sequence analysis of 21 mutants that escaped neutralization or binding by tgev-specific monoclonal antibodies (mabs), and by epitope scanning (pepscan). site a contains the ...19911711257
sequence of the s gene from a virulent british field isolate of transmissible gastroenteritis virus.subgenomic mrna from a virulent field isolate of porcine transmissible gastroenteritis virus (tgev), strain fs772/70, was used to produce cdna. the cdna from three overlapping clones was sequenced by the chain termination method and two open reading frames (orfs) were identified. the largest orf, 4350bp, encoded a polypeptide of 1449 amino acids of relative molecular mass (mr) 159811, which contained 33 potential n-linked glycosylation sites, a cysteine-rich region, and a potential transmembrane ...19901964522
establishment of transformed swine fibroblast cell lines using sv40 large t antigen.swine testicle cell lines were established by transformation of primary swine testicle (pst) cells with an sv40 plasmid (psv3-neo), which contains genes conferring resistance to neomycin and expressing sv40 large t antigen. plasmid dna was transfected into pst cells using a lipofection system. two related plasmids, psv2-neo and psv5-neo, failed to induce transformed cells. cells transformed with psv3-neo formed single colonies that were resistant to the antibiotic, g418, and expressed large t an ...19902175590
sites of replication of a porcine respiratory coronavirus related to transmissible gastroenteritis virus.a porcine respiratory coronavirus (prcv) was inoculated by aerosol into nine hysterectomy-derived and colostrum-deprived pigs at the age of one week. they were killed at different times after inoculation and tissues were sampled for virus isolation and immunofluorescence. results indicate that virus replicated to high titres in the respiratory tract. replication mainly occurred in alveolar cells but also in epithelial cells of nasal mucosa, trachea, bronchi, bronchioli, in alveolar macrophages a ...19902159175
minus-strand copies of replicating coronavirus mrnas contain antileaders.the 5' leader sequence on mrnas of the porcine transmissible gastroenteritis coronavirus was determined and found to be 90 nucleotides in length. an oligodeoxynucleotide with a sequence from within the leader was used as a probe in northern analysis on rna from infected cells, and an antileader (a minus-strand copy of the leader sequence) was shown to be present on all mrna minus-strand species. rnase protection analysis showed the antileader to be approximately the same length as the leader. th ...19911985203
lactogenic immunity to transmissible gastroenteritis (tge) of swine induced by the attenuated nouzilly strain of tge virus: passive protection of piglets and detection of serum and milk antibody classes by elisa.piglets of eight sows vaccinated by different routes with the attenuated tge mutant coronavirus, nouzilly (n) strain, and piglets from two field seropositive sows were challenged with a virulent tge strain. on the day of challenge and 10 days after challenge, milk and serum samples from sows were analysed for their level of neutralizing antibodies, total immunoglobulin classes and tge antibody classes by an elisa. no direct relationship was seen between the level of protection of the litters and ...19902156374
serologic survey for transmissible gastroenteritis virus neutralizing antibodies in selected feral and domestic swine sera in the southern united states.serum samples collected from feral and domestic swine (sus scrofa) in florida and feral swine in georgia and texas were assayed by plaque reduction for their virus neutralizing (vn) antibodies against the porcine transmissible gastroenteritis virus (tge). none of 560 samples collected from feral swine contained vn antibodies for tge virus, but experimentally infected feral swine seroconverted. none of 665 samples from domestic swine contained tge-vn antibodies. these results indicate feral swine ...19902167395
characterization of blood mononuclear cells producing ifn alpha following induction by coronavirus-infected cells (porcine transmissible gastroenteritis virus).porcine blood mononuclear cells (pbmc) were shown to produce interferon-alpha (ifn alpha) following incubation with cells infected by a coronavirus, transmissible gastroenteritis virus. monoclonal antibodies (mab) with specificities for leukocyte subsets and major histocompatibility complex (mhc) antigens were used to characterize ifn alpha producer cells. the production of ifn alpha was found to be a function of non-phagocytic, non-adherent, non-t, non-b, cd4+ (and to a lesser extent cd8+) mhc- ...19902167506
expression of the porcine transmissible gastroenteritis coronavirus m protein.cloned cdna encoding the m protein of the porcine transmissible gastroenteritis coronavirus (tgev) was introduced into a vaccinia virus to examine the function of the amino-terminal signal peptide. the m protein expressed by the recombinant virus was targeted to the golgi region of infected cells, as is the m protein in cells infected with tgev. the protein appeared not to undergo processing other than glycosylation. however, the vaccinia-expressed m protein was slightly larger than the protein ...19901966402
expression of tgev structural genes in virus vectors. 19901966407
nucleotide sequence of the e2-peplomer protein gene and partial nucleotide sequence of the upstream polymerase gene of transmissible gas gastroenteritis virus (miller strain).the e2-peplomer protein gene of the virulent miller strain of transmissible gastroenteritis virus (tgev) was sequenced from cdna clones and compared to the e2 gene sequence of the avirulent purdue strain. sequence comparisons indicate that most amino acid differences occur in the n-terminal half of the e2-peplomer which represents the most exposed region of the protein. in addition, analysis of an incompletely sequenced open reading frame (orf) to the immediate 5' side of the e2 gene indicates e ...19901966416
coronavirus subgenomic replicons as a mechanism for mrna amplification. 19901966420
genomic organisation of a virulent isolate of porcine transmissible gastroenteritis virus. 19901966423
background paper. the appearance of the porcine respiratory coronavirus has created new problems and perspectives. 19901966432
induction of the 2-5a system by interferon and transmissible gastroenteritis virus.interferon (ifn) treatment increased the level of 2',5'-oligoadenylate (2-5a) synthetase and inhibited replication of transmissible gastroenteritis virus (tgev) in cultured swine testicular cells. despite a minimal increase in tgev titer in ifn-treated swine testicular cells, there was rapid cellular destruction. ifn-treated swine testicular cells had detectable levels of 2-5a (3.6 nm 6 h post-infection) after infection with 30 pfu tgev/cell. infection of neonatal pigs with a virulent strain of ...19892481702
the interferon sensitivity of selected porcine viruses.the objective of this study was to compare the sensitivity of 11 porcine viruses to the antiviral effects of porcine interferon-alpha in serum from piglets which had been infected 19 h previously with transmissible gastroenteritis virus, and of porcine interferon-beta prepared in pk-15 cells by induction with polyinosinic:polycytidylic acid, in yield reduction assays in pig kidney cells which were treated with interferon before virus challenge, and both before and after virus challenge. the most ...19892492445
induction of milk iga antibodies by porcine respiratory coronavirus elisa was developed to examine the prevalence of tgev-specific immunoglobulin (ig)a in the milk of sows, infected in the field with prcv or with tgev. it was shown that previous prcv-infections can induce the secretion of iga antibodies in the milk. however, only 9 out of 28 prcv-infected sows had iga in their milk whereas 11 tgev-infected sows all secreted iga. on farms where a reinfection with prcv occurred, the number of iga-secreting sows increased from 2 to 11 on a total of 13 sows. this ...19901966433
[the influence of previous infections on the development of experimental swine pleuropneumonia in specific pathogen free pigs].this study was designed to determine in six-week old specific pathogen free pigs, the effect of previous experimental exposure to mycoplasma hyopneumoniae and transmissible gastroenteritis virus on a challenge infection with actinobacillus pleuropneumoniae. pigs exposed simultaneously to m. hyopneumoniae and transmissible gastroenteritis virus appeared more resistant to challenge (one week later) with a. pleuropneumoniae. four pigs out of a group of ten died following the challenge infection, co ...19892531628
sites of replication of a porcine respiratory coronavirus in 5-week-old pigs with or without maternal antibodies.on farms, where the porcine respiratory coronavirus (prcv) is enzootic, pigs usually become infected between 5 and 10 weeks of age while losing their maternal antibodies. it was examined whether prcv replicates in the small intestine in such pigs. this point is important since intestinal replication with prcv might induce immunity against tgev not only by stimulating mucosal intestinal immunity, but also by the induction of a lactogenic iga response at later age via the gut-mammary link. five we ...19901966434
infection with a new porcine respiratory coronavirus in denmark: serologic differentiation from transmissible gastroenteritis virus using monoclonal 1984 neutralizing antibodies against transmissible gastroenteritis virus (tgev) were detected in pig herds in a small geographical area in the southern part of denmark. no clinical symptoms were observed and accumulating epidemiological evidence gradually pointed towards a respiratory infection. in 1986 a tge-like virus, tentatively named porcine respiratory coronavirus (prcv), was isolated from the lungs of swine. the virus was partially characterized using monoclonal antibodies against tgev ...19901966435
molecular aspects of the relationship of transmissible gastroenteritis virus (tgev) with porcine respiratory coronavirus (prcv). 19901966436
porcine respiratory coronavirus differs from transmissible gastroenteritis virus by a few genomic deletions.the genome organization of porcine respiratory coronavirus (prcv), a newly recognized agent which has a close antigenic relationship to the enteropathogenic transmissible gastroenteritis virus (tgev), was studied. genomic rna from cell-cultured prcv (french isolate rm4) was used to produce cdna clones covering the genomic 3' end to the start of the spike (s) glycoprotein gene (7519 nucleotides). six open reading frames (orfs) were identified that allowed the translation of three coronavirus stru ...19902174956
antigenic structure of transmissible gastroenteritis virus. i. properties of monoclonal antibodies directed against virion proteins.thirty-two hybridoma cell lines producing monoclonal antibodies (mabs) against the three major structural proteins of transmissible gastroenteritis virus (tgev) have been isolated. radioimmunoprecipitation of intracellular viral polypeptides showed that 17 hybridomas recognized both the peplomer protein [e2, 220 x 10(3) mol. wt. (220k)] and a lower mol. wt. species (e'2, 175k), which was characterized as a precursor of e2. six mabs selectively immunoprecipitated the e'2 protein. four hybridomas ...19862418148
kinetics of the in vitro antibody response to transmissible gastroenteritis (tge) virus from pig mesenteric lymph node cells, using the elisaspot and elisa tests.a method is described for in vitro studies of viral humoral immune responses in the pig. after oral immunization with transmissible gastroenteritis (tge) coronavirus, antibody production from primed mesenteric lymph node cells was revealed by an in vitro boost with viral antigen. for the latter the leukocytes were co-cultured with uv-inactivated virus using a variety of different methods of antigenic stimulation. enumeration of specific antibody-secreting cells (asc) and titration of secreted an ...19902167914
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