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1.
采用增殖的鸡传染性鼻气管炎病毒（ARTV）NL7784株，经PEG－20000浓缩液提纯抗原和纯化羊抗鸡IgG抗体，建立了检测ARTV抗体的间接酶联免疫吸附试验。该试验的最佳反应条件为：包被液为pH9.6的0.05mol/L碳酸盐缓冲液，抗原最佳稀释度为1：160，以含6％犊牛血清（CS）的磷酸盐缓冲液作为封闭液，稀释液用含10％CS、0.5% Tween-20的磷酸盐缓冲液，抗原与血清结合的最佳反应时间为30min；酶标抗体的最佳稀释倍数为1：1000，酶联反应的最佳时间为30min，底物的最佳反应时间为15min。本方法具有良好的特异性、稳定性、可重复性和较高的敏感性。  相似文献   

2.
通过制备兔抗鸡传染性腔上囊病病毒（IBDV）、小鼠抗IBDV和绵羊抗兔免疫血清,并纯化绵羊抗兔辣根过氧化物酶标记抗体,采用方阵滴定法测定其最佳使用浓度,建立了IBDV双夹心ELISA检测方法。结果显示,包被抗体的最适稀释度为1：160,兔抗IBDV的最佳稀释度为1：200,酶标记抗体的最佳稀释度为1：400。特异性和重复性试验结果表明,该方法特异性强,重复性好,与鸡新城疫、鸡传染性支气管炎和鸡减蛋综合征病毒抗原均不发生交叉反应。对人工感染病例的检测结果表明,建立的双夹心ELISA方法可用于临床快速诊断IBDV。  相似文献   

3.
间接酶联免疫吸附试验检测禽流感抗体的最佳工作条件   总被引：2，自引：0，他引：2  
禽流感病毒（ＡＩＶ）感染的鸡胚尿囊液经差速离心后,再经蔗糖密度梯度离心,提纯ＡＩＶ,纯化的ＡＩＶ经ＮＰ４０处理并反复冻融,即为ＡＩＥＬＩＳＡ抗原,用该抗原包被聚苯乙烯微量反应板。将健康鸡ＩｇＧ提纯后免疫兔,制备兔抗鸡ＩｇＧ,用过碘酸钠法制备辣根过氧化物酶标记的兔抗鸡ＩｇＧ。确立了间接酶联免疫吸附试验（ＥＬＩＳＡ）检测禽流感抗体的最适工作条件,即：抗原包被浓度１．９～３．８μｇ／ｍｌ,每孔１００μｌ,４℃冰箱过夜;用含０．５％牛血清白蛋白（ＢＳＡ）的磷酸盐缓冲液,３７℃封闭６０分钟;待检血清最佳稀释度为１８０～１６４０,作用６０分钟;酶标抗体作１２０００稀释,作用６０分钟。根据对５２份ＳＰＦ鸡血清的检测结果制定了判定标准。  相似文献   

4.
以醋酸纤维素膜作为固相载体，辣根过氧化物酶标记鸡抗传染性法氏囊病病毒抗体，饱和二氨基联苯胺为底物显色，建立了鸡传染性法氏囊病双抗体夹心Ｄｏｔ－ＥＬＩＳＡ诊断法，经方阵实验确定最佳反应条件为：ＩｇＧ的包被液为０．０５ｍｏｌ／Ｌ（ＰＨ９．６）碳酸盐缓冲液，包被浓度为１、５０；酶标抗体的工作浓度为１；１００；洗涤液为含０．０５％吐温－８０的０．０２ｍｏｌ／Ｌ（ＰＨ７．４）磷酸盐缓冲液；封闭液为含０．２％  相似文献   

5.
采用SF 9昆虫细胞-杆状病毒系统重组表达牛传染性鼻气管炎病毒gD蛋白抗原,经纯化鉴定后将gD蛋白用胶体金标记作为示踪抗原,未标记的gD抗原作为捕获抗原,并以羊抗牛IgG抗体作为质控抗体,建立了牛传染性鼻气管炎病毒双抗原夹心法胶体金检测试纸条。试验结果表明,该试纸条检测灵敏度高,特异性良好,与牛口蹄疫病毒、牛病毒性腹泻病毒等阳性血清无交叉反应。使用建立的胶体金试纸条和IDEXX牛传染性鼻气管炎病毒抗体ELISA检测试剂盒同时检测112份牛血清,阳性符合率为93.5%,阴性符合率为96.0%,总符合率为94.6%。说明该试纸条可以应用于临床牛传染性鼻气管炎病毒抗体的诊断和检测。  相似文献   

6.
将表达有蓝舌病毒ＶＰ７蛋白的Ｓｆ２１细胞超声波处理制备ＶＰ７抗原,建立了ＶＰ７－ＥＬＩＳＡ检测蓝舌病抗体的方法,确定阴性阳性判定界值及最佳反应条件：待检牛血清阳性下限为３．０,羊血清阳性下限为２．４,ＶＰ７抗原包被浓度为１：８００,用含５％健康鸡血清的磷酸盐缓冲液作封闭液,待检血清１：１００稀释,豚鼠抗牛羊ＩｇＧ－ＨＲＰ结合物１：５００稀释,３７℃避免显色４ｍｉｎ～６ｍｉｎ。试验结果表明：ＶＰ７可与２３个不同血清型ＢＴＶ抗体反应,具有较高的群特异性和敏感性。  相似文献   

7.
SPA-ELISA监测猪传染性胃肠炎病毒血清抗体水平的研究   总被引：1，自引：0，他引：1  
建立了SPA—ELISA监测猪传染性胃肠炎病毒(TGEV)血清抗体水平的方法，与免疫荧光试验(IFA)符合率高达90．9％。试验表明：病毒抗原最适包被浓度为4μg／ml；血清工作浓度为1：200；最佳包被液采用0．05m pH9．6的碳酸缓冲液；封闭液选用2％的脱脂奶；并确定了抗原抗体最佳反应时间和最适反应温度及底物溶液的显色时间。特异性试验表明所组装的SAP—ELISA试剂盒特异性较好，可用于TGE的流行病学调查。  相似文献   

8.
以醋酸纤维素膜作为固相载体，辣根过氧化物酶标记鸡抗传染性法氏囊病病毒抗体（ＩＢＤ—ＩｇＧ），饱和二氨基联苯胺为底物显色，建立了鸡传染性法氏囊病双抗体夹心Ｄｏｔ—ＥＬＩＳＡ诊断法。经方阵实验确定最佳反应条件为：ＩｇＧ的包被液为０．０５ｍｏｌ／Ｌ（ｐＨ９．６）碳酸盐缓冲液，包被浓度为１：５０；酶标抗体的工作浓度为１：１００；洗涤液为含０．０５％吐温—８０的０．０２ｍｏｌ／Ｌ（ｐＨ７．４）磷酸盐缓冲液；封闭液为含０．２％明胶的洗涤液；封闭时间、抗原及酶标抗体的作用时间均为３７℃３０ｍｉｎ。应用本方法和琼扩试验同步检测２０份已知阳性病料、１２０份待检病料和胚毒尿囊液、１０份正常鸡样品，结果表明，Ｄｏｔ—ＥＬＩＳＡ阳性率为９０％，而琼扩试验为４０％；凡琼扩试验阳性者，Ｄｏｔ—ＥＬＩＳＡ均呈强阳性，而在Ｄｏｔ—ＥＬＩＳＡ阳性样品中，只有４４％呈琼扩试验阳性，Ｄｏｔ—ＥＬＩＳＡ的敏感度为琼扩试验的１００倍。  相似文献   

9.
用兔抗牛病毒性腹泻病毒(BVDV)多抗作为包被抗体,BVDV NS3单克隆抗体作为捕获抗体,建立了检测BVDV抗原的捕获ELISA方法,对各项反应条件进行优化,最终获得最佳工作条件为兔多抗1∶1 600稀释包被,NS3单抗1∶2 000稀释,酶标抗体工作浓度为1∶4 000稀释。特异性和敏感性试验结果表明,该方法对牛轮状病毒、牛传染性鼻气管炎病毒、牛分支杆菌无特异性交叉反应,其最低可检测7.9×103个TCID50的病毒量,与RT-PCR方法的相比较,符合率为100%。所建立的BVDV抗原捕获ELISA方法快速、特异、敏感,可用于BVDV抗原的检测。  相似文献   

10.
鸡传染性支气管炎ELISA抗体检测试剂盒的研究   总被引：1，自引：0，他引：1  
利用鸡传染性支气管炎M41株病毒研制了检测鸡传染性支气管炎抗体的ELISA试剂盒。抗原最佳包被浓度为0．973ug／ml，被检血清最佳稀释度为1：200，酶标结合物最适工作浓度1：1200，血清样品阴阳性临界值为0．184。本试剂盒和Aflfinitech的IB试剂盒同时检测56份血清样品，比较结果表明本试剂盒的特异性和敏感性分别为100％和88％。试剂盒保存期试验结果表明，试剂盒可保存6个月。  相似文献   

11.
The prevalence of Chlamydiaceae infections on 258 closed pig breeding farms in Belgium was examined. For this purpose, 258 farms were randomly selected in the provinces West-Vlaanderen (44%), Oost-Vlaanderen (20%), Antwerpen (10%) and Vlaams-Brabant (6%). Of all farms examined, 96.5% were positive for Chlamydia-specific antibodies in ELISA and most were moderately to strongly positive. ELISA results revealed only 9 (3.5%) sero-negative farms. None of the ELISA negative sera reacted in immunoblotting. Only 212 of 249 ELISA positive sera reacted positive in immunoblotting. Additionally, 23 autopsy samples were examined by isolation in Vero cells. The major outer membrane sequence of the one isolate obtained showed 98.6% amino acid homology to the one of Chlamydophila psittaci strain CP3, formerly isolated from a pigeon. Present observations indicate that chlamydial infections are nearly endemic in the Belgian pig population and that Belgian pigs can become infected with C. psittaci. Nevertheless, the role and significance of Chlamydiaceae as pathogens in pigs remain unsolved and require further investigation.  相似文献   

12.
Hantaviral antibodies were detected in the sera from Apodemus (A.) agrarius and A. peninsulae captured in Ningxia province, China by several different serological diagnostic methods. A total of 409 sera from rodent and insectivore species were collected in 1999 and examined by indirect immunofluorescent antibody assay (IFA). Among them, 19 of 191 (9.9%) sera of A. agrarius and 1 of 13 (7.7%) sera of A. peninsulae were positive for hantaviral antibodies. The other species (Rattus norvegicus, Mus musculus, Cricetulus triton, and Sorex cylindricauda) were negative. The reaction pattern of positive serum was characterized as scattered and granular virus antigens in the cytoplasm of hantavirus infected Vero E6 cells. Some of the A. agrarius sera positive for hantavirus were further examined by Western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and the focus reduction neutralization test (FRNT). By WB, positive sera showed the same specific reaction pattern of baculovirus-expressed recombinant hantaviral nucleocapsid protein, as shown in hantavirus-immune serum. By ELISA, IFA-positive sera showed significantly higher optical densities (around 1.0) than the negative A. agrarius sera. Hantaan type hantavirus was neutralized with the positive sera. These results suggest that A. agrarius have hantavirus infection and may play a role as a reservoir animal for hantavirus in Ningxia Hui Autonomous Province, China.  相似文献   

13.
Peste des petits ruminants (PPR) is an acute, febrile, highly contagious and economically important viral disease of small ruminants. A polyclonal antibody based indirect ELISA was developed for detection of antibodies to PPR virus in the serum samples of goats and sheep using purified PPR viral antigen propogated in Vero cell culture. A threshold (cut-off) value was set as twice the mean of the negative population based on the distribution of known negative serum samples in respect of PPR virus antibodies in the test. A total of 1544 serum samples from goats and sheep were screened by indirect ELISA and competitive ELISA. The indirect ELISA compared very well with competitive ELISA, with a high degree of specificity (95.09%) and sensitivity (90.81%). When compared with virus neutralization test, the present assay had 100% specificity and 80% sensitivity. With serum samples, the assay could clearly differentiate animals from the infected population from uninfected ones. These results suggest that the indirect ELISA may be a good alternative tool to competitive ELISA for seroepidemiological surveys.  相似文献   

14.
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   

15.
OBJECTIVE: To evaluate the effectiveness of a commercially available ELISA kit for detecting antibodies against Borrelia burgdorferi in dogs. SAMPLE POPULATION: Banked sera from 440 military working dogs were used for serologic analyses. PROCEDURE: Serum samples were analyzed for antibodies against B burgdorferi by use of a commercially available ELISA and subsequently by western blot analysis as a confirmatory test. RESULTS: Results from the ELISA indicated that 89 (20%) samples were positive for exposure to B burgdorferi or canine Lyme disease vaccine, and 351 (80%) were negative. Follow-up testing by western blot analysis indicated that results for 109 (25%) samples were positive and 331 (75%) were negative for exposure. All samples that had positive results on the ELISA also had positive results on western blot analysis (true positives). Of the 351 samples that had negative results on the ELISA, only 331 had negative results on western blot analysis (true negatives). The remaining 20 samples had positive results on western blot analysis. By use of a standard 2 x 2 table, it was determined that the ELISA had a sensitivity of 82%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 94%. CONCLUSIONS AND CLINICAL RELEVANCE: The commercial ELISA kit evaluated in this study appeared to lack adequate sensitivity for detecting all potential cases of borreliosis in dogs. The ELISA was also unable to discriminate natural exposure from exposure attributable to vaccination, which could complicate interpretation of positive results and treatment of dogs with clinical signs.  相似文献   

16.
Two thousand nine hundred fifty-two serum samples, collected once or twice annually from 545 cows of known fecal culture status were tested for antibodies to Mycobacterium avium subsp. paratuberculosis using a commercially available enzyme-linked immunosorbent assay (ELISA) test. Overall, 13.5% of the samples from 282 infected cows had positive ELISA results, but when tested multiple times, 38.3% of the cows had at least 1 serum sample with positive results. Among 263 fecal culture-negative cows, 98.1% of the serum samples had negative ELISA results, but when tested multiple times, 7.8% of the cows had at least 1 positive ELISA sample. Fecal culture was positive on a test before the first positive ELISA in 50 cows, ELISA was positive before fecal culture in 12 cows, and in 38 cows, both tests became positive at the same testing time. An additional 174 cows were positive on fecal culture and always negative on ELISA until culled. For cows that had ELISA sample:positive (S/P) ratios below the cutoff point, the change in S/P between sequential tests was evaluated to determine whether a rise in S/P could predict infection status. In this study, change in S/P was not a useful predictor of infection status in seronegative cows.  相似文献   

17.
The main theme of this project was to develop a Vero cell-adapted, thermostable NDV I-2 vaccine and evaluate its efficacy against challenge infection. For this purpose, serial passages of virus were done in Vero cell line up to 13 times and after each passage samples were subjected to heat treatment at 56°C for 40 min. After 13 passages, the virus was completely adapted on Vero cell line and cytopathic effects were observed, including syncytial formation, rounding, degeneration, and detachment of cells. Hemagglutination and infectivity titers showed that the virus was thermostable after each passages in Vero cell line. One-day-old broiler chicks (Group 1) were vaccinated orally with thermostable NDV I-2 vaccine. A commercially available thermolabile NDV LaSota was used in Group 2 used as positive control. NDV I-2 vaccine produced maximum % inhibition migration at d 6 (50%) as compared with LaSota ND vaccine (i.e., 32%). On encounter with virulent NDV I-2, 100% safety was accomplished in group 1 and 60% in case of group 2. All the birds in the control negative group had died. This study led to the conclusion that thermostable Vero cell adapted I-2 strain vaccine resulted in better immunization in broiler birds than obtained by the use of commercially available thermolabile vaccines.  相似文献   

18.
Feline sera were submitted to the Cornell Feline Health Center (n = 497) or to the New York State Diagnostic Laboratory (n = 1,565) for feline immunodeficiency virus (FIV) testing. Some sera (n = 166) were submitted for confirmation of previous FIV-positive results; 151 of these sera had been tested at the referring veterinary practice or laboratory, using an in-house ELISA. Excluding the samples submitted for confirmation, a total of 173 samples (9.1%) were FIV-positive; 11.6% of the clinically ill or high-risk cats and 0.49% of the healthy, low risk cats were positive for FIV antibody. A commercially available ELISA for detection of antibody to FIV was evaluated in relation to the immunofluorescent antibody (IFA) test and the immunoblot assay. The ELISA was interpreted according to the manufacturer's instructions, with the ratio of sample optical density to positive control optical density (S/P) determining a positive or negative result. The ELISA results based on the S/P interpretation were compared with a kinetics-based (KELA) interpretation of the ELISA. The KELA values were reported as positive, negative, or equivocal. Using the immunoblot as the standard, ELISA (S/P interpretation) had sensitivity of 0.93 and specificity of 0.98, whereas the IFA test had sensitivity of 0.95 and specificity of 0.98. However, the sensitivity and specificity of the ELISA (S/P interpretation) were markedly reduced for sample results falling in the KELA equivocal range, indicating that equivocal results were valid interpretations for some sera. A high number (22.5%) of the samples submitted for confirmation of a positive result from use of the in-house ELISA were determined to be negative for FIV antibody.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
An enzyme-linked immunosorbent assay (ELISA) was evaluated for diagnosis of experimental or naturally occurring Fasciola sp. infections in cattle. The positive rate for the ELISA in calves inoculated with Fasciola metacercariae were 21.1% by 2 weeks postinoculation (PI), 94.6% by 4 weeks PI and 100% by 6-21 weeks PI. The positive rate for the immunodiffusion test (Ouchterlony test) reached 91.7% by 2 weeks PI, however, it dropped to 77.8% by 10 weeks PI. The positive rate for the fecal egg examination was 0% by 10 weeks PI, 77.8% by 12 weeks PI and 100% by 14-21 weeks PI. The practical application of ELISA was tested by using 165 cows raised under field condition. All the 24 cows that were positive both in the fecal egg examination and the Ouchterlony test were ELISA positive. Of the 6 cows that were egg positive and Ouchterlony negative, 5 showed ELISA positive reactions. Of the 27 cows that were egg negative and Ouchterlony positive, 24 were ELISA positive. Of the 108 cows that were egg negative and Ouchterlony negative, 90 were ELISA negative. However, the other 18 cows had ELISA positive reactions. Our results suggested that the ELISA using crude adult antigen was superior to the Ouchterlony test and fecal egg examination for diagnosis of experimental or naturally occurring Fasciola sp. infections in cattle.  相似文献   

20.
Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at -70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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