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1.
In calves inoculated with bovine viral diarrhea (BVD) viruses and soluble antigen, the complement-fixing (CF) antibodies appeared before serum-neutralizing (SN) antibodies and remained at high levels throughout the test period. A rapid rise in SN antibodies occurred after challenge with homologous virus with no apparent effect on CF antibody levels.

The CF antibody responses in calves infected with cytopathogenic NADL-MD and noncytopathogenic CG-1220 viruses were similar whereas SN antibody responses indicated strain specificity by reciprocal cross-neutralization tests.

The CF antibody levels in 5 hog cholera (HC) antisera were assayed using the soluble antigen of NADL-MD BVD virus. No demonstrable SN antibodies were present in four HC antisera tested against NADL-MD virus, but a significant titer was present in the commercially prepared antiserum.

Virus was reisolated from animals infected with BVD viruses by buffy coat culture technique during 3 weeks postinoculation, even when significant levels of CF and SN antibodies were present.

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2.
Five monoclonal antibodies against the bovine viral diarrhoea (BVD) viral strain NADL were isolated and characterized by an indirect immunofluorescence assay. Extensive cross-reactions were detected when the antibodies were tested with 12 heterologous BVD and four hog cholera (HC) viral strains. One antibody reacted with all strains tested. Two antibodies were specific for cytopathogenic BVD viruses, but failed to react with HC virus. The other antibodies reacted to varying degrees with BVD and HC viral strains.  相似文献   

3.
Natural infection of pigs with bovine viral diarrhea virus (BVDV) through contact with infected cattle has caused problems in diagnosing hog cholera (HC). Low cross-reacting serum antibody titers against HC caused by BVDV infection were found in clinically normal pigs as well as those suspected of having HC. Bovine viral diarrhea virus was isolated from specimen tissues and initially identified as HC virus (HCV), using the fluorescent antibody cell culture technique. Additional cell cultures, as well as pig and calf trials, were necessary to identify it as BVDV. The isolate caused clinical signs of illness in the calves, whereas the pigs remained healthy. Bovine viral diarrhea virus may be detected in tissue sections or isolated in cell cultures and confirmed as HCV, using the HC fluorescent antibody conjugate. Laboratories performing the neutralization test for HC should use discretion when interpreting HC titers unless BVD titers are determined on the same serums.  相似文献   

4.
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5.
A panel of 30 monoclonal antibodies was defined and characterized with respect to the binding capacity in immunoperoxidase assay to different strains of pestivirus. Using the panel it was possible to identify specifically all strains and isolates of hog cholera virus, hog cholera vaccines derived from 'C' strains, and most strains of bovine viral diarrhoea/border disease (BVD/BD) viruses (including those isolated from pigs). A small proportion of BVD/BD isolates from pigs and ruminants reacted only with the monoclonals specific for pestivirus group antigen. It is recommended that monoclonal typing methods be introduced into official procedures for the diagnosis of hog cholera/classical swine fever.  相似文献   

6.
Fetal serum from most of 994 bovine and 553 ovine aborted fetuses was tested serologically for antibodies to border disease (BD), bovine viral diarrhea (BVD), and bluetongue (BT) viruses, and to Leptospira sp., and the results were compared with the results of isolation procedures, fluorescent antibody tests (FAT), and histologic examinations of the same fetuses. Antibodies to BT virus were not found in any of the 994 bovine and 553 ovine fetuses. Antibody titers to BVD virus were present in 39 of 966 bovine fetuses tested, and BVD virus was detected in 4 of the 39. Four of 74 fetuses in which the BVD virus was detected by FAT or isolation had titers to BVD virus. Microagglutination (MAT) titers to 1 or more of 5 serovars of leptospires were present in 52 of 773 bovine fetal sera tested. Leptospires were not detected by FAT in any bovine fetuses that had leptospiral antibody titers. Leptospires were detected by FAT in 15 aborted calves, and none of these had MAT titers. Antibody titers to BD virus were present in 80 of 486 fetal lamb sera tested, and the virus was detected by FAT or isolation in 3 of the 80 fetuses. Border disease virus was detected in 14 of 486 fetal lambs tested. Twelve of the 14 were tested serologically and 3 had titers to BD virus. Leptospiral antibody titers were present in 27 of 326 ovine fetal sera tested. Leptospires were not detected in any of the 326 ovine fetuses tested by FAT.  相似文献   

7.
An antiserum to a recent field isolate of infectious laryngotracheitis virus was conjugated with fluorescein isothiocyanate and used to detect viral antigen to infected chorioallantoic membranes and trachael epithelium by the direct fluorescent antibody technique. In experimentally infected birds, viral antigen was detected with the fluorescent antibody technique from 2 to 14 days post-inoculation but histological evidence of tracheitis was only observed from day three to day ten. The fluorescent antibody test detected 22 of 23 histologically confirmed cases of ILT and was more accurate than virus isolation when used in the diagnosis of respiratory disease from field outbreaks. It was concluded that the speed, accuracy and sensitivity of the fluorescent antibody technique make it a useful tool in the diagnosis of infectious laryngotracheitis.  相似文献   

8.
Ninety-one cases of neonatal calf diarrhea were examined for viruses with negative contrast electron microscopy. Viruses were demonstrated in 41% of the cases. Reo-like viruses and corona-like viruses, and mixed virus populations were observed in 12%, 20% and 9%, respectively. Twenty-six of the cases were examined by negative contrast electron microscopy, and by virus isolation or by fluorescent antibody technique. There was an 81% agreement in obtained results. The disagreements resulted from the demonstration of a viral agent by negative contrast electron microscopy while the other techniques did not indicate a virus. The results suggest that negative contrast electron microscopy is a more sensitive diagnostic tool for demonstration of viruses associated with neonatal calf diarrhea than are viral isolation or the fluorescent antibody technique.  相似文献   

9.
A panel of monoclonal antibodies was prepared by immunization of BALB/c mice with Moredun (BD) virus strains. These antibodies were characterized by immunofluorescence and seroneutralization against BD, BVD and hog cholera (HC) virus strains, and radioimmunoprecipitation of BVD-infected cells extracts. The MAbs reacting with the majority of the Pestivirus strains recognize the 80 kDa antigen of the BVD cytophathic strains. The 80 kDa antigen of the BVD/Osloss virus strain has been cloned and expressed in E. coli as a fusion protein with beta-galactosidase. The fusion protein has been purified from inclusion bodies and used successfully as an antigen for ELISA detection of BVDV specific antibodies in bovine sera. A competitive ELISA using MAbs is more specific than a direct assay. These results compare well with the ones obtained with antigen extracted from BVDV-infected cells.  相似文献   

10.
Serum samples were collected from early weaned fall calves shortly after the onset of respiratory tract disease. Antibody titers to infectious bovine rhinotracheitis (IBR) virus, parainfluenza type 3 (PI-3) virus, bovine viral diarrhea (BVD) virus, bovine adenovirus type 3 (BAV-3), and bovine respiratory syncytial virus (BRSV) were determined on paired (acute and convalescent) serums. Seroconversion rate (a fourfold or greater rise in antibody titer) for IBR virus was 4.3%, PI-3 virus--16.3%, BVD virus--9.6%, and BAV-3--2.2%. Seroconversion for BRSV was 45.4%. An increased rate of seroconversion for IBR, PI-3, and BVD viruses and BAV-3 was observed in the presence of BRSV seroconversion. These results suggest that BRSV may facilitate infection by other viruses. Results of virus isolation procedures from these calves were negative.  相似文献   

11.
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12.
The antibodies in serum samples from an outbreak of low-virulent hog cholera in Spielbach, West Germany, 1966, as well as serum samples from pigs inoculated with hog cholera (HG) virus and bovine viral diarrhea (BVD) virus, respectively, were examined by means of 3 different methods:
  1. A modified direct complement fixation (GF) test,
  2. A peroxidase-linked antibody (PLA) assay based on microplates with fixed, viral-antigen containing cells,
  3. A neutralization assay carried out in microplates using the “chessboard” principle and read by means of the peroxidaselinked antibody (NPLA) assay.
A good correlation was found in their ability to detect the antibodies. Generally neutralizing antibodies could be found 2 weeks after inoculation. By CF and PLA antibodies could be detected at the same time or up to 2 weeks later. All sera were tested by the 3 methods against both HG viral antigen and BVD viral antigen. HC-antibodies could not be distinguished from BVD-antibodies by CF but to a certain degree by PLA. BVD-antibodies could to a certain degree be distinguished from HG-antibodies by CF but not by PLA. This means that CF and PLA together provide a good possibility for differentiation between the two types of antibodies. NPLA could to a high degree of reliability distinguish between HG-antibodies and BVD-antibodies.  相似文献   

13.
An antigen capture enzyme immunoassay (EIA) for the detection of bovine viral diarrhoea (BVD) viral antigen in peripheral blood lymphocytes of cattle was used for the screening of 241 animals. The test used a monoclonal antibody directed against a conserved antigenic domain of a nonstructural protein (p125/p80) of pestiviruses for antigen capture. Bound antigen was detected with a pestivirus-specific polyclonal peroxidase conjugate. In parallel the samples were analysed by routine virus isolation procedures based on cell culture. Virus isolation and antigen capture EIA were positive in 54 cases. The latter test scored one additional sample.  相似文献   

14.
A reliable bovine viral diarrhea (BVD) viral antigen was prepared from BVD virus grown on Madin Darby bovine kidney (MDBK) cells by solubilizing the virus with detergent MEGA-10 (decanoyl-N-methylglucamide) followed by removal of hydrophobic proteins with Triton X-100 treatment. By these treatments, problems of high background associated with BVD viral antigen in the enzyme-linked immunosorbent assay (ELISA) were eliminated. With this new antigen, an ELISA was adapted to detect bovine serum antibody against BVD virus. The diagnostic specificity of the assay in 403 bovine sera collected from a BVD virus-free herd was 100%; in 296 bovine sera with serum neutralizing antibody titers of greater than or equal to 1:2, 289 sera were ELISA positive (relative sensitivity of 97.6%), two sera gave false negative reactions (0.7%) and five sera gave suspicious reactions (1.7%). These interpretations were based on positive/negative (P/N) ratio readings, i.e. a P/N ratio of less than 1.50, 1.50-1.99 and greater than or equal to 2.00 were interpreted as negative, suspicious and positive reactions, respectively. The ELISA results gave excellent agreement with serum neutralization in detecting both seropositive and seronegative animals (Kappa = 0.994). The ELISA assay was considered to be technically superior to the serum neutralization test for the routine detection of BVD viral antibody in bovine sera.  相似文献   

15.
Organs of 100 calves whose clinical symptoms indicated a BVD/MD viral infection have been examined in the laboratory by different methods on BVD/MD virus in order to compare the effectivity of the single test-systems. By inoculation of organ material into tissue culture from foetal calf kidneys and additional staining with swine-fever conjugate in the CCSC-system 59 calves were detected as BVD/MD virus carriers. Taking this result for comparative purposes equal to 100% there could be stated an effectivity of 73% by inoculation of tissue cultures and judging cpe instead of staining with fluorescent antibody as above. Only 34% reactions could be demonstrated by means of heterotypic immunofluorescence in organ tissues. For diagnostic purposes a combination of the easy and quick method of heterotypic immunofluorescence in organ tissues and a cultural virus isolation from organ material with additional immunofluorescence is recommended.  相似文献   

16.
牦牛病毒性腹泻/粘膜病的防制研究   总被引：10，自引：0，他引：10  
20世纪80年代以来，我国牦牛群中陆续发现牛病毒性腹泻／粘膜病(BVD／MD)，血清阳性率在30％～42．4％之间，病死率在30％左右，本研究先后从四川、西藏等地牦牛中分离出病毒，并对其进行各种生物学特征鉴定后，表明该病毒与标准毒属同一种，所不同的是四川牦牛病毒株属非致细胞病变型，即属NCP型。但回归本动物能复制出典型病例。目前尚无国产牛粘膜病疫苗用于生产。本研究依据猪瘟病毒与牛病毒性腹泻／粘膜病病毒具有交叉免疫性的原理，用猪瘟弱毒苗对牦牛病毒性腹泻／粘膜病进行预防，试验证明用猪瘟弱毒苗可以预防牛病毒性腹泻／粘膜病，且安全可靠，具有实用价值。  相似文献   

17.
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18.
Both cytopathic and noncytopathic bovine viral diarrhea virus (BVDV) were isolated from 16 of 17 bovine spleens representing 11 herds that had experienced acute BVD and from 12 of 21 bovine spleens from 1 herd affected with chronic BVD. It was concluded that isolation of cytopathic and noncytopathic BVDV from the same spleen probably indicates that an animal with a persistent, noncytopathic BVDV infection was superinfected with a cytopathic BVDV. The prevalence (greater than 70%) of 2 viruses in the spleen of cattle with acute or chronic BVD suggested that persistent infection with noncytopathic BVDV may be an important factor in the pathogenesis of BVD.  相似文献   

19.
Isolates of non-cytopathogenic bovine viral diarrhoea (BVD) virus from 18 persistently infected calves from one herd were compared by using monoclonal antibodies directed against the major viral glycoprotein gp53. All the isolates displayed an almost identical reaction pattern. Based on this antigenic analysis three cytopathogenic BVD and three non-cytopathogenic BVD viruses closely related to the non-cytopathogenic BVD herd isolate were selected. Six of the persistently infected calves were inoculated with a pool of the three closely related cytopathogenic BVD viruses and two with a pool of the three non-cytopathogenic BVD viruses. In addition three animals were infected with one closely related cytopathogenic BVD strain (Indiana) and two animals with the antigenetically different cytopathogenic BVD viral strain A1138/69. Regardless of the inoculation route all the animals superinfected with closely related cytopathogenic BVD viruses developed the characteristic lesions of mucosal disease within 14 days of infection. Animals which were inoculated with non-cytopathogenic BVD viruses which closely resembled the herd isolate, or with cytopathogenic BVD viruses which did not resemble the herd isolate did not develop any signs of disease. However, the latter group produced antibodies to the superinfecting virus.  相似文献   

20.
A 2-step technique for the isolation of hog cholera (HC) virus consisting of an initial culture on buffy coat (BC) cultures and subinoculation to a pig kidney cell line (PK-15) was described. By this technique, HC virus was confirmed in specimens from 65 herds in which the conventional cell culture isolation technique failed. The herds were located in 20 states and Puerto Rico. Specimens from 29 of the 65 herds were inoculated into specific-pathogen-free (SPF) pigs. Hog cholera virus was recovered from 27 of the test pigs. The 2 pigs from which virus was not recovered had signs of acute infection and, on necropsy, had gross lesions of HC infection.  相似文献   

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