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A new sandwich enzyme-linked immunosorbent assay (S-ELISA) kit that uses raw (unprocessed) fetal bovine serum (FBS) as the testing sample was evaluated for upstream bovine viral diarrhea virus (BVDV) testing. Pooled FBS samples (n = 84) were tested using the S-ELISA. Thirty serum samples originating from persistently infected (PI) calves that had been confirmed by virus isolation (VI) as BVDV positive and another 30 samples previously confirmed by VI as BVDV negative were also evaluated. Of the 84 field samples, the S-ELISA detected 13 (15.5%) BVDV-positive specimens. When these 13 positive samples were tested by VI and immunofluorescent assay, 11 (84.6%) were positive and 2 (15.4%) were negative. The S-ELISA was positive for all 30 PI samples (100%) and negative for all 30 negative samples (100%). These data indicate that the new kit is a relatively reliable diagnostic tool and can be considered for upstream detection of BVDV-contaminated raw FBS pools. 相似文献
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Larson RL Miller RB Kleiboeker SB Miller MA White BJ 《Journal of the American Veterinary Medical Association》2005,226(2):249-254
OBJECTIVE: To develop partial budgets of the economic costs of 2 test strategies for screening cattle for persistent infection with bovine viral diarrhea virus (BVDV). DESIGN: Partial budget analysis. ANIMALS: 938 calves arriving at 2 stocker operations. PROCEDURE: Calves were tested to determine prevalence of persistent BVDV infection. Test strategies that were evaluated included a single-test strategy consisting of immunohistochemical staining of skin biopsy specimens from all animals and a 2-test strategy consisting of polymerase chain reaction (PCR) assaying of pooled blood samples followed by immunohistochemical staining of skin biopsy specimens from animals in pools for which assay results were positive. Break-even costs (i.e., cost of persistent BVDV infection per animal necessary to justify whole-herd diagnostic testing) associated with each test strategy were calculated as a function of disease prevalence and test cost. RESULTS: Apparent prevalence of persistent BVDV infection was 0.32%. Sensitivity and specificity of the PCR assay for pooled samples were 100% and 89.7%, respectively. Regardless of the prevalence of persistent BVDV infection, the break-even cost for the 2-test strategy was lower than the break-even cost for the single-test strategy. However, the economic advantage was greatest when prevalence was low. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that using a 2-test strategy to screen cattle for persistent BVDV infection, whereby the first test involves PCR assaying of pooled samples and the second involves immunohistochemical testing only of those animals represented in pooled samples with positive assay results, will reduce the cost of screening incoming feedlot cattle, compared with immunohistochemical testing of all animals. 相似文献
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Stokstad M Niskanen R Lindberg A Thorén P Belák S Alenius S Løken T 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2003,50(9):424-429
Nineteen pregnant cows were experimentally infected with bovine viral diarrhoea virus (BVDV) between day 74 and 81 of pregnancy. All cows became infected and developed serum antibodies. Sixteen of the cows delivered persistently infected (PI) offspring, whereas the remaining three gave birth to calves with detectable serum antibodies and free from BVDV. The 16 cows with PI foetuses developed higher levels of antibodies in serum during pregnancy than did their three peers carrying non-PI calves. Multivariate analysis showed that the antibody levels in these two groups of cows were significantly different from day 135 of pregnancy. Foetal fluid was successfully collected from 18 of the 19 infected cows and from five uninfected control cows between 10 and 24 days before delivery by use of a percutaneous, blind puncture technique. No negative effects were observed in the cows or their offspring. BVDV was isolated and detected with an immunoperoxidase test in foetal fluid from 13 of the 16 cows carrying PI foetuses, and from 15 of the cows when a quantitative fluorescent polymerase chain reaction (PCR) technique was used. The negative sample in the PCR assay was positive for BVDV antibodies. The number of viral copies per microlitre in foetal fluids varied between 103 and 1080 in the positive samples. All samples taken from the cows carrying non-PI foetuses were negative for BVDV in both assays. In this experiment, examination of either serum or foetal fluids could identify the cows carrying a PI foetus. Examination of serum for BVDV antibodies was a reliable indicator of a PI foetus if the serum was collected during the last 2 months of pregnancy. For examination of foetal fluids, both viral and serological analyses should be performed. For viral analysis, PCR should be the test of choice. High levels of BVDV antibodies in conjunction with a negative result in the PCR may be indicative of a false-negative virus result. Further experience with the method of collection of foetal fluids is necessary for evaluation of its safety. Investigation of pregnant cows in order to discover a PI offspring before it is born could be a useful tool in control and eradication of BVDV. 相似文献
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Khan F Vorster JH van Vuuren M Mapham P 《Journal of the South African Veterinary Association》2011,82(1):18-23
Research aimed at optimising diagnostic laboratory procedures is central to the development of effective bovine viral diarrhoea virus (BVDV) control programmes. BVDV is a single-stranded RNA virus that crosses the placenta to infect foetuses, resulting in reproductive losses due to foetal death or persistently infected calves that die early in life. Persistently infected animals are widely accepted to be the primary reservoir of BVDV and the largest source of infection. This poses important challenges to overall animal/herd health and can cause major losses to the cattle industry. Long-term storage of bovine ear notch samples from calves persistently infected with BVDV may adversely affect the ability of diagnostic assays to detect the virus efficiently. In order to test this hypothesis, ear notch samples from 7 animals were divided into 2 groups. One set was subjected to prompt formalin fixation and the other set stored either as fresh samples without preservatives at -2 degrees C, or soaked overnight in phosphate buffered saline followed by freezing of the supernatant fluid at -2 degrees C. Frozen ear notches and ear notch supernatant yielded positive results with an antigen-capture, enzyme linked immunosorbent assay (AC-ELISA) for the duration of the study (6 months) and optical density (OD) values remained significantly within range. There was no significant difference between storing fresh ear notch samples or PBS at -2 degrees C. However, positive immunohistochemistry (IHC) staining on formalin fixed ear notches started to fade between Day 17 and Day 29 when stored at room temperature. It was concluded that fresh ear notches could safely be stored at -2 degrees C for a period of 6 months prior to testing for BVD viral antigens. 相似文献
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Kleiboeker SB Lee SM Jones CA Estes DM 《Journal of the American Veterinary Medical Association》2003,222(10):1399-1403
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B J Hooft van Iddekinge J L van Wamel H G van Gennip R J Moormann 《Veterinary microbiology》1992,30(1):21-34
We used the polymerase chain reaction (PCR) technique to detect bovine viral diarrhea virus (BVDV) infections in cattle. Of 120 cattle screened in this study, 29 were scored positive for BVDV with both PCR and conventional virus isolation. Ninety cattle were negative in both assays. One cow was scored positive for BVDV with the PCR but was negative with virus isolation. In dilution experiments PCR analysis was at least 10 times more sensitive than BVDV isolation. 相似文献
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Gripshover EM Givens MD Ridpath JF Brock KV Whitley EM Sartin EA 《Veterinary microbiology》2007,125(1-2):11-21
Bovine viral diarrhea virus (BVDV) affects cattle populations causing clinical signs that range from subclinical immunosuppression to severe reproductive and respiratory problems. Detection and removal of persistently infected (PI) calves is the single most important factor for control and eradication of BVDV. Current testing strategies to detect PI calves rely heavily on immunohistochemistry (IHC) and a commercially available antigen capture ELISA (ACE) assay. These viral assays depend on 1 or 2 monoclonal antibodies which target the E(rns) glycoprotein of BVDV. The sensitivity and specificity of these two tests have been reported previously. The purpose of this research was to characterize a strain of BVDV (AU501) that was undetectable using IHC and ACE based on a single monoclonal antibody, but was consistently detected in samples from a Holstein steer using virus isolation and PCR testing. Sequencing of this AU501 viral isolate revealed a unique mutation in the portion of the genome coding for the E(rns) glycoprotein. This unique field strain of BVDV demonstrates the risk of relying on a single monoclonal antibody for detection of BVDV. Multiple testing strategies, including polyclonal or pooled monoclonal antibodies that detect more than one viral glycoprotein may be necessary to detect all PI calves and facilitate eradication of BVDV. 相似文献
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AIM: To assess the ability of two commercial bovine viral diarrhoea (BVD) virus (BVDV) antigen-capture enzyme-linked immunosorbent assays (ELISAs) to detect virus in serum and skin biopsies. METHODS: Thirty cattle persistently infected (PI) with BVDV were identified using routine diagnostic laboratory testing. Additional ear-notch skin biopsies and blood samples were collected from these animals to confirm the diagnosis, and from 246 cohorts, to determine their BVDV status. Skin biopsies were soaked overnight in buffer and the eluate collected. All sera and eluate were tested using two commercially available ELISAs for detecting BVDV antigen, and a subsample of positive and negative sera was tested using a polymerase chain reaction (PCR) test. A study was also performed to ascertain the risk of cross contamination occurring during the collection and processing of skin biopsies. RESULTS: Both serum and skin samples tested using either ELISA resulted in the detection of all cattle identified as PI and no non-infected cattle were incorrectly classified as infected using either method. Agreement between all assays (ELISAs, whether performed on serum or skin, and PCR) was 100%. No cross-contamination of skin samples between animals was evident using routine biopsy methods. CONCLUSIONS: Viraemic cattle infected with BVDV were accurately identified using either of the two commercial ELISAs evaluated on either serum or skin samples. CLINICAL RELEVANCE: Either skin biopsies or serum samples can be collected from cattle to determine their BVDV status. This should overcome problems in accurately identifying the infection status of young calves in which colostral antibodies might interfere with the antigen-capture ELISA. 相似文献
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Multiple diagnostic tests to identify cattle with Bovine viral diarrhea virus and duration of positive test results in persistently infected cattle 
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下载免费PDF全文 Robert W. Fulton Bill E. Hessman Julia F. Ridpath Bill J. Johnson Lurinda J. Burge Sanjay Kapil Barbara Braziel Kira Kautz Amy Reck 《Canadian journal of veterinary research》2009,73(2):117-124
Several tests for Bovine viral diarrhea virus (BVDV) were applied to samples collected monthly from December 20, 2005, through November 27, 2006 (day 0 to day 342) from 12 persistently infected (PI) cattle with BVDV subtypes found in US cattle: BVDV-1a, BVDV-1b, and BVDV-2a. The samples included clotted blood for serum, nasal swabs, and fresh and formalin-fixed ear notches. The tests were as follows: titration of infectious virus in serum and nasal swabs; antigen-capture (AC) enzyme-linked immunosorbent assay (ELISA), or ACE, on serum, nasal swabs, and fresh ear notches; gel-based polymerase chain reaction (PCR) testing of serum, nasal swabs, and fresh ear notches; immunohistochemical (IHC) testing of formalin-fixed ear notches; and serologic testing for BVDV antibodies in serum. Of the 12 animals starting the study, 3 died with mucosal disease. The ACE and IHC tests on ear notches had positive results throughout the study, as did the ACE and PCR tests on serum. There was detectable virus in nasal swabs from all the cattle throughout the study except for a few samples that were toxic to cell cultures. The serum had a virus titer ≥ log10 1.60 in all samples from all the cattle except for 3 collections from 1 animal. Although there were several equivocal results, the PCR test most often had positive results. The BVDV antibodies were due to vaccination or exposure to heterologous strains and did not appear to interfere with any BVDV test. These findings illustrate that PI cattle may be identified by several tests, but differentiation of PI cattle from cattle with acute BVDV infection requires additional testing, especially of blood samples and nasal swabs positive on initial testing. Also, calves PI with BVDV are continual shedders of infectious virus, as shown by the infectivity of nasal swabs over the 11-mo study. 相似文献
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Challenge with Bovine viral diarrhea virus by exposure to persistently infected calves: protection by vaccination and negative results of antigen testing in nonvaccinated acutely infected calves 下载免费PDF全文
下载免费PDF全文 Robert W. Fulton Bill J. Johnson Robert E. Briggs Julia F. Ridpath Jeremiah T. Saliki Anthony W. Confer Lurinda J. Burge Douglas L. Step Derek A. Walker Mark E. Payton 《Canadian journal of veterinary research》2006,70(2):121-127
Calves persistently infected (PI) with Bovine viral diarrhea virus (BVDV) represent an important source of infection for susceptible cattle. We evaluated vaccine efficacy using calves PI with noncytopathic BVDV2a for the challenge and compared tests to detect BVDV in acutely or transiently infected calves versus PI calves. Vaccination with 2 doses of modified live virus vaccine containing BVDV1a and BVDV2a protected the calves exposed to the PI calves: neither viremia nor nasal shedding occurred. An immunohistochemistry test on formalin-fixed ear notches and an antigen-capture enzyme-linked immunosorbent assay on fresh notches in phosphate-buffered saline did not detect BVDV antigen in any of the acutely or transiently infected calves, whereas both tests had positive results in all the PI calves. 相似文献
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O'Connor AM Reed MC Denagamage TN Yoon KJ Sorden SD Cooper VL 《Journal of the American Veterinary Medical Association》2007,230(11):1691-1696
OBJECTIVE: To report the prevalence of bovine viral diarrhea virus (BVDV) in calves and calf groups (ie, calves from the same farm) in beef breeding herds and evaluate the ability of biosecurity risk assessment questionnaires to identify calf groups with positive results for BVDV. DESIGN: Nonrandom survey. ANIMALS: 12,030 calves born in spring from 102 operations. PROCEDURES: Cow-calf producers that voluntarily enrolled in a screening project submitted ear notch specimens from calves and answered a 29-question survey instrument. Ear notch specimens were tested for BVDV with an antigen-capture ELISA (ACE), and ear notch specimens with positive ACE results for BVDV were immediately retested by performing immunohistochemistry (IHC). Follow-up testing, 3 to 4 weeks after initial positive ACE results, was done by use of a second IHC test and virus isolation on a subsequently submitted ear notch specimen from the same calves to identify those that were persistently infected (PI). RESULTS: 102 producers submitted ear notch specimens for BVDV screening. Initially, 24 of 12,030 calves had positive ACE results for BVDV. A second ear notch specimen was submitted for 20 of these 24 calves. Of 20 retested calves, 12 had positive ICH results for BVDV, confirming PI status. The 12 PI calves came from 4 calf groups (3 singletons and 1 calf group with 9 PI calves). CONCLUSIONS AND CLINICAL RELEVANCE: Prevalence of BVDV in calf groups was low, and questions designed to identify high-risk biosecurity behaviors had little value in identifying calf groups with positive results for BVDV. 相似文献
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M. Stokstad R. Niskanen A. Lindberg P. Thorn S. Belk S. Alenius T. Lken 《Zoonoses and public health》2003,50(9):424-429
Nineteen pregnant cows were experimentally infected with bovine viral diarrhoea virus (BVDV) between day 74 and 81 of pregnancy. All cows became infected and developed serum antibodies. Sixteen of the cows delivered persistently infected (PI) offspring, whereas the remaining three gave birth to calves with detectable serum antibodies and free from BVDV. The 16 cows with PI foetuses developed higher levels of antibodies in serum during pregnancy than did their three peers carrying non‐PI calves. Multivariate analysis showed that the antibody levels in these two groups of cows were significantly different from day 135 of pregnancy. Foetal fluid was successfully collected from 18 of the 19 infected cows and from five uninfected control cows between 10 and 24 days before delivery by use of a percutaneous, blind puncture technique. No negative effects were observed in the cows or their offspring. BVDV was isolated and detected with an immunoperoxidase test in foetal fluid from 13 of the 16 cows carrying PI foetuses, and from 15 of the cows when a quantitative fluorescent polymerase chain reaction (PCR) technique was used. The negative sample in the PCR assay was positive for BVDV antibodies. The number of viral copies per microlitre in foetal fluids varied between 103 and 1080 in the positive samples. All samples taken from the cows carrying non‐PI foetuses were negative for BVDV in both assays. In this experiment, examination of either serum or foetal fluids could identify the cows carrying a PI foetus. Examination of serum for BVDV antibodies was a reliable indicator of a PI foetus if the serum was collected during the last 2 months of pregnancy. For examination of foetal fluids, both viral and serological analyses should be performed. For viral analysis, PCR should be the test of choice. High levels of BVDV antibodies in conjunction with a negative result in the PCR may be indicative of a false‐negative virus result. Further experience with the method of collection of foetal fluids is necessary for evaluation of its safety. Investigation of pregnant cows in order to discover a PI offspring before it is born could be a useful tool in control and eradication of BVDV. 相似文献
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Kuhne S Schroeder C Holmquist G Wolf G Horner S Brem G Ballagi A 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2005,52(6):272-277
A new diagnostic approach testing tissue samples derived from cattle ear tagging for bovine viral diarrhoea virus (BVDV) antigen in a commercially available antigen capture enzyme-linked immunosorbent assay (ACE) was developed. To validate this method, 99 positive and 469 negative samples were tested. With those samples the assay yielded a sensitivity of 100% and specificity of >or=99.6%. Serum and ear tissue samples from 11 persistently infected (PI) BVDV calves were tested. While serum samples were negative after intake of colostrum, the ear tissue samples could be detected positive for BVDV all the time. Testing multiple samples derived from the same ear from PI cattle yielded positive results and low variation. Using cattle ear tags combining the ear tag application with sampling of a small ear tissue plug and testing those tissue samples with an ACE could be a reliable and economic way of BVDV testing. 相似文献