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1.
Bovine blood containing bluetongue virus was stored as whole blood with EDTA (4 degrees C), as washed cellular components (4 degrees C), and as washed cellular components with 10% DMSO (-70 degrees C). Periodic isolation attempts were made over a period of 330 days in four cell lines and embryonating chicken eggs (intravenous inoculation). Bluetongue virus was successfully isolated in all systems from most samples throughout the test period. There appeared to be more variation amongst days of attempted isolation within systems than between systems.  相似文献   

2.
Isolation of bluetongue virus was attempted from 85 semen samples taken from 3 long-term seropositive bulls and 9 short-term seropositive bulls in an artificial breeding service unit. Two types of cell cultures susceptible to bluetongue virus were used for virus isolation. Extended sonication, centrifugation of specimens, and treatment of cell cultures with dimethyl sulfoxide and diethylaminoethyl-dextran were used to enhance virus attachment and infection of cell cultures. Virus isolation results were negative on all specimens. These results indicate that at the limits of the methods used, bluetongue virus-seropositive bulls do not have long-term latent bluetongue virus in their semen.  相似文献   

3.
Infectious bursal disease viruses (IBDVs) were isolated from turkeys showing symptoms of arthritis and respiratory disease in commercial poultry farms in the province of Quebec, Canada. Synovial fluids collected from hock joints of arthritic birds and peripheral blood leukocytes obtained from the birds with respiratory problems were used for virus isolation in embryonated chicken eggs, and Vero and BGM-70 cell cultures. The infected cells were evaluated for the presence of IBDV by indirect immunofluorescence assay using monoclonal antibodies. The viruses were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of viral genome and by electron microscopy. Although one of these turkey isolates tested was neutralized by serotype 1-specific commercial chicken antisera, preliminary results indicated that there are antigenic differences between the Quebec isolate, IBDV QT-1, and the existing strains of IBDV belonging to serotype 1.  相似文献   

4.
Epizootiologic study of bluetongue: virologic and serologic results   总被引:5,自引:0,他引:5  
Heparinized blood and serum samples were obtained from 1,295 ruminants in herds or flocks with bluetongue virus (BTV) infection in 4 western states. Submissions were from herds or flocks with clinical bluetongue (BT), as well as from animals on premises with no history of BT disease. Insects, including Culicoides variipennis, were collected in areas enzootic for BT disease. Viral isolations were in 10-day-old embryonating chicken eggs that were then adapted to Vero cells for serotyping. Sera were tested from group-specific antibody to BTV by the micro agar gel precipitin (AGP) test. Viral isolations were from cattle (81), sheep (122), goats (9), antelope (2), and C varipennis (5). There were 7 isolates of serotype 120, 114 of serotype 11, 42 of serotype 13, and 56 of serotype 17. In herds or flocks from which BTV was isolated, 51% of cattle, 56% of sheep, 21% of goats, and 52% of antelope had AGP antibodies. Virus was isolated from 43% of the cattle and 23% of the sheep that had no demonstrable evidence of AGP antibodies. Viral isolations were seasonal, occurring from August until December. Approximately 30% of the herds or flocks from which virus was isolated had more than one serotype of virus causing infection.  相似文献   

5.
Lumpy skin disease virus (LSDV), a poxvirus of the genus Capripoxvirus, is shed in the semen of infected bulls. The screening of semen for infectious virus requires a sensitive diagnostic method. The isolation of the virus on cell cultures and/or the polymerase chain reaction (PCR) are sensitive diagnostic tests which may be used to screen semen for LSD viral DNA prior to artificial insemination. Although cell culture detects infectious virus and is a sensitive method, there are major difficulties in using this method due to the toxic effect of semen on the cells. The aim of this study was to find a method that decreases the toxic effect of semen and enhances the isolation of LSDV on cell culture. Semen samples from LSDV sero-negative bulls were collected and infected with a field isolate of LSDV, strain V248/93, with a titre of 6.5 log TCID50. The semen samples were treated with one of four different methods: centrifugation, serial dilution, filtration and chemical treatment with kaolin. The samples subjected to centrifugation, serial dilution and filtration were supplemented with gentamycin. Semen toxicity on cell cultures was eliminated when supernatants of semen samples centrifuged at 2000 rpm for 1, 3 and 5 min and serially diluted were used to inoculate confluent monolayer bovine dermis cells. The toxicity recorded when the pellet fractions of semen samples centrifuged for 5 min at 2000 rpm was comparable to results obtained from serially diluted samples supplemented with gentamycin. Filtration and kaolin treatment of semen samples did not remove the toxic effect.  相似文献   

6.
Twenty-six samples known to contain infectious bursal disease virus (IBDV) were examined by virus-isolation attempts on ovine kidney (OK) cell line, Vero cell line, and chicken embryo fibroblast (CEF) cultures. Virus was isolated from two of 26 samples, three of 26 samples, and three of 25 samples on OK, Vero, and CEF cultures, respectively. However, in contrast to IBDV replication in Vero and CEF cultures, isolated virus was unable to induce serially sustained cytopathic effects (CPE) during successive passages in the OK cell line, unless cell lysates were treated with chloroform between every other passage. The cytopathogenicity of the untreated virus passaged in OK cells was revived and maintained upon passage in Vero cells. An initial single passage of laboratory or field material in OK cells followed by further passages in Vero cells resulted in virus isolation from six of 26 samples, which was better virus recovery than when either cell line was used alone or when CEF cultures were used. Twenty of the 26 test samples were originally positive when examined by nucleic acid hybridization with radiolabeled IBDV cDNA, indicating that some of the samples that were negative upon virus isolation using OK and Vero cells may have contained inactivated virus.  相似文献   

7.
Epizootic hemorrhagic disease virus (EHDV) was isolated in Vero cell culture from the spleen and whole blood of a white-tailed deer (Odocoileus virginianus). A 10% spleen suspension caused acute hemorrhagic disease (HD) when inoculated into an experimental white-tailed deer and resulted in the recovery of EHDV from the blood of the experimental animal at 5 days after inoculation. The virus was identified as EHDV serotype 2 through indirect fluorescent antibody tests, electron microscopy, and reciprocal cross-neutralization tests. Approximately 73% (36/49) of the mule deer, 5% (2/42) of the white-tailed deer, and 79% (249/314) of the cattle samples tested from areas where HD had been reported were EHDV seropositive. Although none of the white-tailed deer was bluetongue virus seropositive, 29% of the mule deer and 3% of the cattle tested from "active" HD areas possessed bluetongue virus precipitating antibody.  相似文献   

8.
A group of 20 sentinel steers was bled weekly for 5 months in 1986 and the blood samples were examined for arboviruses by inoculation firstly into embryonated chicken eggs (ECE), baby mice, Aedes albopictus cells and BHK21 monolayers. A second group of cattle was similarly examined for virus in 1987, except that baby mice were not used. Viruses were recovered from 26% of the 878 weekly bleeds. The viruses identified consisted of 14 types belonging to the bluetongue, epizootic haemorrhagic disease (EHD), Palyam and Simbu groups with a single isolation of bovine ephemeral fever virus. The ECE system was found to be the best for isolating bluetongue and Simbu viruses, though the eggs were not usually killed by the inoculum. The ECE and A. albopictus systems were equally sensitive for recovering EHD viruses, while Palyam group viruses were most efficiently isolated in BHK21 monolayers.  相似文献   

9.
Electron microscopy (EM) and genome electropherotyping by polyacrylamide gel electrophoresis (PAGE) for the detection of avian rotaviruses and reoviruses in intestinal specimens and cell cultures were compared. Fifty-eight field samples of intestine with intestinal contents, referred to as direct specimens, from turkey and chicken flocks located in different regions of California and submitted during 1989 for virus isolation were randomly selected as test samples. Also, 38 field intestinal specimens with suspected viral infection that had been passaged three times in primary chicken embryo kidney (CEK) cell cultures were used in their third passage. The percentage of agreement and the Kappa statistic of positive and negative results between these two tests were calculated. In the comparison, EM was considered the standard test. By statistical analysis, an agreement of 87% was observed in cell-culture samples analyzed by the two virus-detection methods, as contrasted with an agreement of 72% for direct specimens. The analysis of the number of segments and band migration profiles of reference and field virus strains indicated that only reoviruses replicated in CEK cell cultures and mainly rotaviruses were detected by both tests in direct specimens. The Kappa statistic analysis indicated substantial agreement (0.69) between the two tests for CEK samples, with moderate agreement (0.45) for the direct specimens examined.  相似文献   

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12.
For the diagnosis of chlamydiosis in dead and live birds different methods were compared for their sensitivity and specificity. The specificity of the modified Giménez staining and the direct immunofluorescence (DIF) test for direct demonstration of Chlamydia psittaci in organ, cloacal and/or conjunctival smears was examined. The sensitivity of the isolation of Chlamydia psittaci in 6 days embryonated specific pathogen free (SPF) chicken eggs, Buffalo Green Monkey (BGM) cell line, McCoy cell line and Vero cell line was compared. On smears, the direct immunofluorescence test was more specific than the modified Giménez staining. The concordance between the results of both detection methods was 80%. The BGM cell culture was the most sensitive artificial host for isolation of Chlamydia psittaci, followed by the embryonated eggs, the Vero cell line and the McCoy cell line. The concordance between the results of isolation in BGM cell culture and eggs was 96.5%, while it was 86% between the results of isolation in BGM cell culture and Vero cell culture and only 65.5% between the results of isolation in BGM cell culture and McCoy cell culture. For dead bird species, chlamydiosis could be diagnosed more often using DIF on smears than with isolation. The concordance between the results of the DIF on smears and isolation followed by DIF was 91%.  相似文献   

13.
Culturing of Chlamydia psittaci from pet birds requires the inoculation of a susceptible living host system with suspensions of various tissues from dead birds or with tracheal and/or cloacal swabs and fresh feces from live birds. Cell cultures have been used as the host system. The most commonly used cell cultures for isolation of C psittaci from pet birds are McCoy and mouse L cells. The sensitivity and specificity of cell culture equals or surpasses embryonating chicken eggs and mice, and results can be obtained in less than 7 days. To obtain satisfactory results, the inoculum must be centrifuged onto the cell cultures at 37 C, and the cells must be treated with a metabolic inhibitor such as colchicine or cycloheximide. Chlamydia psitaci can be detected in infected cells by use of fluorescent antibody, Giemsa, or Gimenez staining.  相似文献   

14.
A virus was isolated from the spleen of a white-tailed deer (Odocoileus virginianus) that had died during an epizootic in Washington state in 1967. Inoculation of a 10% spleen suspension from the deer caused hemorrhagic disease in normal white-tailed deer. Studies were conducted on the biological, physicochemical, and serologic properties of the Washington isolate. An in vitro assay system, utilizing a cultured primary of white-tailed deer fetal cells from an entire fetus, was employed for isolation and propagation of the virus. Cytopathic effect was characterized by focal development of rounded and clumped cells. Propagation was unsuccessful in suckling mice, BHK-21, and Vero cell cultures. The virus was resistant to treatment with ether, sodium deoxycholate, trypsin, oxytetracycline hydrochloride, and was sensitive to chloroform. Virus yield was not affected when infected cultures were treated with 5-iodo-2'-deoxyuridine, but dactinomycin (actinomycin D) treatment of infected cultures reduced virus yield. The virus was inactivated when heated at 70 C for 5 minutes or when exposed to pH 5 for 18 hours at 4 C. The virus was completely excluded from the filtrate by a 0.10- micronm (APD) membrane filter. Staining of infected cells with acridine orange indicated the presence of double-standard nucleic acid in the cytoplasm. Serum-neutralization tests with antiserums against the homologous virus and the New Jersey and Alberta strains of epizootic hemorrhagic disease virus resulted in neutralization of the Washington isolate. The Washington virus was not neutralized by bluetongue virus antiserum. Cells infected with the Washington isolate exhibited intracytoplasmic fluorescence by the indirect fluorescent antibody method with New Jersey and Alberta epizootic hemorrhagic disease antiserums but not with bluetongue antiserum.  相似文献   

15.
A monoclonal antibody (mAb) directed against the equine arteritis virus (EAV) nucleocapsid (N) protein was used for indirect enzyme-linked immunosorbent assays (ELISAs) using viral antigen from different sources. The same mAb was labelled with fluorescein isothiocyanate for direct immunofluorescence tests (DIFTs). The N-specific mAb appeared to be suitable for the detection in both ELISA and DIFT of different EAV strains and field isolates from semen and tissue samples after passage in lines of RK-13, Vero and fetal equine kidney cells. The ELISA described is an easy and fast method which can be used in most cases to replace the microneutralization test to prove the EAV specificity of the cytopathic effect of cell cultures. The DIFT, however, is more sensitive than both the ELISA and the microneutralization test because EAV antigen can be detected even in cell cultures without or with very weak cytopathic effect.  相似文献   

16.
A monoclonal antibody (mAb) directed against the equine arteritis virus (EAV) nucleocapsid (N) protein was used for indirect enzyme‐linked immunosorbent assays (ELISAs) using viral antigen from different sources. The same mAb was labelled with fluorescein isothiocyanate for direct immunofluorescence tests (DIFTs). The N‐specific mAb appeared to be suitable for the detection in both ELISA and DIFT of different EAV strains and field isolates from semen and tissue samples after passage in lines of RK‐13, Vero and fetal equine kidney cells. The ELISA described is an easy and fast method which can be used in most cases to replace the microneutralization test to prove the EAV specificity of the cytopathic effect of cell cultures. The DIFT, however, is more sensitive than both the ELISA and the microneutralization test because EAV antigen can be detected even in cell cultures without or with very weak cytopathic effect.  相似文献   

17.
Ascending paralysis developed in 3 dogs, 12 to 14 days following inoculation with a modified live virus, chicken embryo origin, low egg passage, Flury strain rabies vaccine. The paralysis began in the inoculated limb but rapidly involved both hindlimbs. Partial paresis of the forelimbs was seen several days following the hindlimb paralysis in all 3 dogs, and in 1 of these dogs the infection ascended rapidly to the brain as well. Two of the dogs recovered within 1 and 2 months, respectively, but the 3rd dog died within 5 days of the onset of paralytic signs. The fatal case was complicated by naturally acquired coincidental distemper. Serologic studies in 2 dogs and virus isolation from the 3rd dog indicated that rabies virus was the cause of the paralysis in 2 of the dogs and contributed to the disease syndrome in the 3rd dog. Virus could not be isolated from the saliva of CSF of the 2 surviving dogs. The virus isolated in the fatal case appeared to have some of the characteristics of the vaccine virus, as determined by its behavior in mice, cell culture, and embryonating chicken eggs and by its failure to produce Negri bodies in the brain of the infected dog.  相似文献   

18.
Bluetongue: Laboratory diagnosis   总被引:2,自引:0,他引:2  
Definitive diagnosis of bluetongue virus (BTV) infection, often subclinical in domestic and wild ruminant relies heavily on laboratory techniques for BTV isolation and demonstration of BTV antigens, viral nucleic acids and antibodies. The virus can be isolated from blood components, mainly the erythrocyte fraction, collected from affected animals during the period of febrile response. Semen collected from male animals at the peak of viremia and tissues from affected animals and fetuses may also be used for BTV isolation. The primary procedure for BTV isolation is inoculation of embryonated chicken eggs with a subpassage onto cell cultures (e.g. BKH-21, Vero cell lines). In addition to the conventional techniques such as fluorescent antibody staining and virus neutralization procedures for sero-grouping and serotyping of BTV isolates, immunohistochemical, immunoenzymatic and immunoelectron microscopic techniques, using monoclonal antibodies (MAb), offer more rapid, specific and sensitive approaches for BTV identification and antigen detection. The progress of molecular biology, especially the development of genetic probes for hybridization analysis and polymerase chain reaction techniques for detection of BTV nucleic acids hold the promise of most efficient diagnostic assays. Among the various serogroup-specific assays for antibody detection, the agar gel immunodiffusion (AGID) and competitive (C) ELISA are the most widely used tests. Because of its limitations (i.e. anticomplementary serum and complexity of the procedure) the complement fixation (CF) test is virtually abandoned and is used in only a few laboratories. Although the AGID test is simple to perform and rapid, it is not highly sensitive or quantitative and has limitations in its specificity. Sera containing antibodies to other group of Orbiviruses (e.g. epizootic hemorrhagic disease) may result in non-specific reaction in the AGID test. Among several ELISAs that have recently been developed, the C.ELISA in which a group-specific MAb to BTV is used, has proved to be the most sensitive and specific assay for detection of antibodies to BTV. Following extensive national and international validation, the C.ELISA is gradually replacing the AGID as a universal test to certify ruminants for trade purposes and to diagnose BT infection in domestic and wild animals. The cell culture-based microtiter serum neutralization (MTSN) is the most commonly used assay for the detection of serotype-specific antibodies to the recognized BTVs in animal sera. The MTSN may be used to type virus isolates and also to monitor animal population for specific serotypes of BTV in epidemiological investigations.  相似文献   

19.
Small groups of bulls were exposed to natural infection with arboviruses. The bulls were bled and ejaculated regularly and the blood and semen were processed for virus isolation. Over a 5-year observation period, virus isolation and serology indicated that the 29 exposed bulls had experienced 79 viraemic episodes with the viruses of the bluetongue, epizootic haemorrhagic disease, Palyam and Simbu serogroups and an incompletely characterised rhabdovirus. In no instance was there unequivocal evidence of bluetongue virus contamination of semen, despite 18 infections in the study period.  相似文献   

20.
The avidin-biotin complex immunoperoxidase technique was adapted for use in detecting bluetongue virus (BTV) antigens in BTV serotype 11-infected bovine fetuses. Fetuses were infected with BTV serotype 11 at 120 days of gestation and then removed 20 days later by Cesarean section. Blood and tissue samples were collected from each animal and used for virus isolation in embryonated chicken eggs, the immunofluorescent antibody test, and the avidin-biotin complex test. The avidin-biotin complex method successfully identified BTV antigens in both fresh and autolyzed fetal brains. Thus, the avidin-biotin complex immunoperoxidase method has potential as a possible procedure for diagnosing bluetongue disease in aborted bovine fetuses.  相似文献   

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