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1.
以纯化的牛分枝杆菌重组MPT83蛋白为包被抗原,建立了检测牛分枝杆菌抗体的间接ELISA方法。确定了间接ELISA各组分的最适反应条件:抗原包被浓度为1μg/mL,酶标二抗稀释度为1:1600,血清稀释度为1:60,抗原和血清、血清和二抗均在37C反应30min,底物在37℃显色15min,D655nm阴性、阳性临界值为0.5。经阻断试验、交叉试验、重复性试验,表明该方法特异性强、重复性好。用该方法对18份结核菌素试验阳性牛血清和36份结核菌素试验阴性牛血清进行检测,结果显示,阳性血清的符合率为27.8%,阴性血清的符合率为91.7%。  相似文献   

2.
我国A群牛轮状病毒感染的血清流行病学调查   总被引:1,自引:0,他引:1  
为调查A群牛轮状病毒(BRV)在我国不同地区牛群中的感染和流行情况,本研究采用间接ELISA检测2005年~2006年期间在我国12个不同地区收集的1760份牛血清中抗A群BRV抗体。结果显示,其强阳性血清225份(12.8%);中等阳性血清1240份(70.4%);弱阳性血清279份(15.9%);阴性血清16份(1%)。总抗体阳性率高达99%。不同地区强阳性、中等阳性及弱阳性血清所占比例有所不同。结果表明,A群BRV在我国牛群中的感染和流行不但非常广泛,而且极为严重。本研究对我国BRV感染进行了较大规模的血清流行病学调查,其结果可为我国犊BRV腹泻疾病的防制提供重要的依据。  相似文献   

3.
为了研究以弓形虫致密颗粒蛋白GRA1为抗原检测猫弓形虫感染的血清学诊断及评价,试验采用标准弓形虫抗体阳性、阴性猫血清建立ELISA方法,最终确定重组GRA1最佳蛋白包被浓度为5μg/m L、血清最佳稀释度为1∶64,用此方法对已通过MAT/IFA法共同确定的185份猫弓形虫抗体血清进行检测并评价。结果表明:应用MAT/IFA法检出阳性血清39份、阴性血清146份,而通过重组GRA1-ELISA法检出阳性血清37份、阴性血清148份,二者共同检出阳性血清33份、阴性血清142份,GRA1假阳性率为10.8%,假阴性率为4.1%。比较重组GRA1-ELISA与MAT/IFA的结果,二者不一致部分无显著性差异(P0.05);一致性部分经Kappa检验(K=0.83),一致率为94.6%。说明以重组GRA1作为包被抗原建立的ELISA方法检测效果没有弓形虫体裂解蛋白TLA好。因此,重组GRA1不是用于检测猫弓形虫感染的流行病学调查的最佳诊断抗原。  相似文献   

4.
为建立猪链球菌病的快速诊断方法,本研究以纯化的原核表达的猪链球菌溶菌酶释放蛋白(MRP)为包被抗原,通过各反应条件的优化建立了检测猪链球菌(SS)血清抗体的间接ELISA方法。实验确定了最佳抗原包被浓度为0.05μg/mL、待检血清最佳稀释倍数为1:400、最佳封闭液为5%脱脂乳、兔抗猪HRP-IgG的最佳稀释倍数为1:15 000、抗体阴阳性临界值为0.226。特异性试验结果显示,利用本研究建立的ELISA方法检测100份背景清晰的阴性血清,检出其中97份阴性血清,3份阳性血清,特异性为97%。利用该ELISA方法检测副猪嗜血杆菌、胸膜肺炎放线杆菌、多杀巴氏杆菌、大肠杆菌、猪传染性胃肠炎病毒、轮状病毒、流行性腹泻病毒、猪繁殖与呼吸综合征病毒阳性血清,结果显示均为阴性,而猪链球菌2型(SS2)、SS7、SS9以及SS12阳性血清的检测结果均为阳性,表明该方法具有较强的特异性。敏感性试验结果显示,利用本研究建立的ELISA方法检测50份背景明确的阳性血清,检出其中48份阳性血清,2份阴性血清,敏感性为96%。当SS2阳性血清稀释倍数达1:3 200时仍为阳性结果,表明该方法具有较高的敏感。重复性试验结果显示,该ELISA方法批内、批间最大变异系数分别为4.70%和7.20%,表明该方法的重复性较好。对100份临床猪血清样品检测结果显示,本研究建立的ELISA方法与玻片凝集试验的符合率为85.3%,符合率较高。对440份来自东北三省部分地区猪场的血清样品检测结果显示,SS抗体阳性率为27.7%(122/440)。表明,东北三省部分地区猪场SS的感染率较高。上述结果表明,本研究建立的间接ELISA方法可以用于SS2、SS7、SS9以及SS12血清抗体的检测,为SS病的血清流行病学调查提供了可靠的技术手段。  相似文献   

5.
应用衣原体间接血凝实验(IHA)对来自青海省门源县东部地区的200份牛血清、200份羊血清进行了衣原体间接血凝抗体试验的检测。结果检出:牛阳性血清16份,血清阳性率为8.0%;羊阳性血清35份,血清阳性率为17.5%;说明在该县东西部地区的牛羊群中存在衣原体病的感染。  相似文献   

6.
以纯化的犬新孢子虫(Neospora caninum)重组蛋白 NcSRS2t为抗原包被酶标板,通过对间接ELISA 各反应条件的优化,确定了最佳反应条件.采用已建立的间接ELISA反应条件,对218份阴性血清的检测结果进行统计学分析,确定了间接ELISA的判定标准,即OD450nm值大于等于O.32为阳性,小于O.32为阴性.应用建立的间接ELISA方法对128份阴性血清和50份阳性血清(经IDEXX公司新孢子虫抗体检测试剂盒证实)进行检测,结果表明,闻接ELISA方法的特异性为93.0%,敏感性为90.0%.采用本试验建立的新孢子虫间接ELISA 诊断方法对黑龙江省克山、海林、双城、甘南、克东、富裕、牡丹江、大庆等8个县(市)奶牛场的540份奶牛血清进行了检测.结果表明,被检的540份奶牛血清样本中奶牛新孢子虫的抗体阳性率为13.33%.该间接ELISA 诊断方法的建立及初步应用为新孢子虫病诊断试剂盒的研制和新孢子虫病的预防研究奠定了基础.  相似文献   

7.
应用金免疫层析技术检测猪瘟抗体的研究   总被引:9,自引:2,他引:7  
用金标免疫层析技术测试30份标准阳性血清和18份标准阴性血清,结果阳性,阴性符合率100%。用该方法与ELISA试剂、dot-ELISA试剂及正向间接血凝进行比对试验检测血清样品205份,结果阳性率ELISA为86.8%,金标层析法为85.4%,dot-ELISAO 81.5%,正向间接血凝为58.5%,结果显示该方法特异性强,敏感性高,操作简单,使用方便。既可用血清,也可以用全血测猪瘟抗体,可广泛应用于猪场和个体养猪户现场检测。  相似文献   

8.
用禽脑脊髓炎病毒免疫的鼠阳性血清作为诊断抗体,对21份待检禽血清和10份病料进行检测,其结果如下:抗体阻断荧光试验(ABET)检测21份血清中,阳性血清11份,阴性血清10份,中和试验测得,阳性血清11份(NI>1.17),阴性血清10份;琼扩试验测得阳性血清5份。间接免疫荧光试验测得10份病料中有7份阳性,2份可疑,1份阴性,用这些可疑病料脑内接种1日龄雏鸡,成功  相似文献   

9.
用培养的布氏杆菌菌体,通过超声波裂解、反复离心制备出布氏杆菌细胞壁抗原。将细胞壁抗原作1:128稀释,用作牛种布氏杆菌酶联免疫吸附试验(ELISA)的抗原;将布氏杆菌细胞壁抗原作1:32稀释,用作平板凝集试验抗原;把细胞壁抗原作1:16稀释用作试管凝集试验抗原,分别建立了牛布氏杆菌ELISA试验、平板凝集试验和试管凝集试验。用这3种方法,检测已知200份平板凝集试验阴性血清,5份平板凝集试验阳性血清。结果5份阳性血清在平板凝集试验、试管凝集试验和ELISA试验中均为阳性;200份阴性血清在平板凝集试验和试管凝集试验中均为阴性,在ELISA试验中有1份为阳性?试验证明,细胞壁抗原,既能用于传统的平板凝集试验和试管凝集试验,又能用于ELISA试验。  相似文献   

10.
将鸽Ⅰ型副粘病毒F基因亚克隆到p GEX-4T-1载体中,并用大肠杆菌BL21(DE3)为宿主菌诱导表达。以纯化的F蛋白为诊断抗原,建立鸽Ⅰ型副粘病毒间接ELISA检测方法,用方阵法确定了间接ELISA检测的最佳条件:抗原1∶128稀释即抗原包被量为0.6μg/孔,血清1∶400稀释,与一抗的最佳作用时间为60 min,与酶标二抗的最佳作用时间为60 min,底物显色的最佳作用时间为15 min。用该方法对实验室保存的35份阳性血清和12份阴性血清进行检测,结果阳性符合率达到97%以上,阴性符号率达100%。  相似文献   

11.
Single dilution ELISAs were standardised for the determination of antibody titres against Theileria annulata using three antigens namely soluble piroplasm, cellular schizont or soluble schizont antigens. Antibody titres of 20 cattle serum samples of known identity were determined by multi-dilution ELISA using the three antigens. The ratio of the optical density (OD) of known positive and known negative sera at different serum dilutions were calculated and termed as positive/negative (P/N) ratios. Coefficients of correlation (r) were calculated between the P/N ratios at different dilutions of known sera and their log10 antibody titres by multi-dilution ELISA. The value of "r" was the highest at the dilution of 1:400. From the log10 antibody titres of known sera and their P/N ratios at the dilution of 1:400, regression equations (Y = a + bX, where Y = predicted log10 titre, X = the P/N ratio at 1:400 dilution) were calculated separately for the three antigens. Thus, the equations Y = 1.63 + 1.35X for soluble piroplasm, Y = 2.67 + 0.547X for cellular schizont and Y = 1.817 + 0.663X for soluble schizont antigens were derived. Test sera were diluted to 1:400 and their OD were read in duplicate wells and converted to P/N ratios. The antibody titres were predicted from the P/N ratios using the above mentioned regression equations. Twenty randomly selected sera tested by single and multidilution ELISAs showed non-significant differences (P < 0.01) between antibody titres. Antibody titres of 90 unknown field sera of cattle were determined by single dilution ELISA. The piroplasm antigen detected higher antibody titres followed by cellular schizont and soluble schizont antigens. The study revealed that a single dilution ELISA could be successfully used for field epidemiological studies of tropical theileriosis.  相似文献   

12.
应用血清中和试验(SNT)和伪狂犬病乳胶凝集试验(LAT)诊断试剂盒对两种伪狂犬病是性血清、伪狂犬病病毒(PRV)高兔血甭及60份被检猪血清进行了PRV抗体效价测定和相关性分析,两种方法测得的抗体效价之间呈强相关性(r=0.96),且LAT效价比SNT一般高出一个滴度;能干为自35个猪场的414份猪血清进行了PRV抗体检测,并与SNT检测结果进行了对比,结果在SNT检测为阳笥的171份血清中,LA  相似文献   

13.
An ELISA, using Encephalitozoon cuniculi spores as antigen, was used to determine the prevalence of specific anti-E cuniculi IgG in a group of stray dogs. In a preliminary survey 51 of 248 sera were classified as positive with titres of 1:400 to 1:3200. The 18 sera with titres of 1:400 were reclassified as negative when no IgG binding to the spores could be detected by comparison with a standard curve of anti-E cuniculi IgG. The remaining 33 sera (13.3 per cent) were classified as low, moderate or strong positives. Comparison of total IgG and specific IgG showed that specific IgG was greatly increased in the moderately and strongly positive sera. E cuniculi may be of importance as one cause of fading puppy syndrome when transmitted transplacentally, and as a complicating infection in human immunodeficiency diseases.  相似文献   

14.
为了掌握高致病性猪蓝耳病(HP-PRRSV)的流行规律,应用病理学、RT-PCR/荧光RT-PCR、血清学试验、流行病学调查等方法对592发病场点的794份组织样品、来自屠宰场的636份健康组织和604份健康猪血清进行HP-PRRSV检测。经检测,发病组织HP-PRRSV样品阳性率为85.01%,健康猪组织HP-PRRSV阳性率为8.18%;健康猪血清HP-PRRSV阳性率为2.32%。另采用ELISA法对604份健康猪血清PRRSV抗体检测,免疫抗体阳性率仅为43.87%。由此可见,HP-PRRS广泛存在重庆市各区县,以仔猪和育肥猪易感且发病率高,5~7月是发病的高峰期,主要在500头以下小规模猪场流行,长期带毒、持续感染、隐性感染、混合感染、免疫应答延迟是本病的流行特点。  相似文献   

15.
A single-dilution, sensitive and specific monoclonal antibody-based blocking enzyme-linked immunosorbent assay (B-ELISA) was developed as an alternative to the cumbersome virus neutralization test (VNT) for detection of equine herpesvirus-1 (EHV-1) antibodies. Neutralizing monoclonal antibodies (1H6 and 9C6) raised against EHV-1 (Hisar-90-7 strain) and sera from 70 horses (30 known negative and 40 known positive for EHV-1 antibodies by VNT) were used for standardization of the B-ELISA. Using a single serum dilution of 1:250 in B-ELISA, 100% specificity was obtained with both monoclonal antibodies (Mabs) in comparison to VNT. Similarly, the sensitivity of the B-ELISA was 92.5% and 100% with 1H6 and 9C6 Mabs, respectively. A very high correlation coefficient (r = 0.85) was observed between B-ELISA and VNT that was significant at the p < 0.01 level. B-ELISA detected a more than 3-fold rise in antibody titres in paired serum samples collected from mares aborting owing to EHV-1 infection. Mab 9C6 was chosen for testing 231 field sera from apparently healthy vaccinated and non-vaccinated horses from organized breeding farms belonging to 11 Indian states, and from Bhutan, by B-ELISA and VNT. There was very good agreement between the results obtained by both VNT and B-ELISA (K = 0.9438). Of 231 field sera, 144 samples were negative for EHV- 1 antibodies by both VNT and B-ELISA and 81 were positive by both tests. Two samples negative by VNT were found positive in B-ELISA. On the other hand, four weakly positive samples in VNT (VN antibody titre 0.9 1.2 log10) were negative in B-ELISA. The Mab (9C6)-based B-ELISA was found to be a suitable alternative to VNT for screening large numbers of field sera and enabled confirmatory EHV-1 serodiagnosis.  相似文献   

16.
An enzyme-linked immunosorbent assay (ELISA) using bulk tank milk samples was evaluated as a screening test for bovine tuberculosis (TB), a contagious chronic disease of cattle. An ELISA with MPB70, a major antigen of Mycobacterium bovis was performed using paired sets of milk and sera samples from 33 tuberculin-positive and 43 tuberculin-negative cattle. Anti-MPB70 antibodies were detected in milk samples and there was a significant correlation between seroreactivities of milk and sera samples (R2 = 0.83). Using the tuberculin skin test as the reference test, the sensitivities of ELISA using milk and sera samples were 87.8% and 81.8%, respectively, and the specificities were 97.7% and 100%, respectively.In the screening test using bulk tank milk samples from 931 dairy herds in Whasung, Gyeonggi-do, Korea, the positive rate for anti-MPB70 antibody was 4.5% (42/931) and the tuberculin-positive rate was 2.8% (26/931). Individual milk samples (n = 253) were collected from randomly selected 8 problematic and 3 negative herds (positive and negative in the screening test by MPB70 ELISA using bulk tank milk samples, respectively) and tested by MPB70 milk ELISA. In the problematic herds, positive rates were 10.5% (20/190) for anti-MPB70 antibodies in milk ELISA and 2.1% (4/190) in the tuberculin skin test. More than one dairy cows were positive by milk ELISA among the problematic herds, and all tuberculin-positive dairy cows were positive in the milk ELISA. Further, no positive cows were detected in negative herds both by milk ELISA and tuberculin skin test. These results suggest that an ELISA, using bulk tank milk samples, might be a potential efficient screening test for bovine TB of dairy cows.  相似文献   

17.
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   

18.
Trials were conducted to verify the possibility of poultry blood sampling with filter papers for subsequent examination of the eluates for the presence (and level) of haemagglutination-inhibition antibodies against the Newcastle disease virus (NDV). Qualitative examination was performed in 294 paired samples of sera and eluates, representing 10 selective sets, coming from three vaccinated poultry flocks. The numbers of positive sera (dilution ratios 1:20 and higher) and positive eluates of filter papers (dilution ratios of 1: 2 and higher) were compared and it was found that there were 238 positive paired samples (81%) and 30 were negative (10.2%), hence, there were like reactions in 268 paired samples (91.2% of the total number of samples examined). It was only in 25 paired samples that positivity was recorded just in the sera: 22 times with a titre of 1:20 and three times with a titre of 1:40. In one case, positivity was recorded just in the eluate. The final titres were compared in 181 paired samples of sera and eluates, all diluted at a ratio of 1:2, and it was found that the concentration of the haemagglutination-inhibition antibodies in the eluates corresponded to serum dilution ratio of 1:20. Under this assumption, the antibodies were found to have the same titre in 164 paired samples (55.8%) during the quantitative evaluation. A lower titre was recorded in 82 eluate samples (27.9%) and a higher antibody titre in 48 eluate samples (16.3%) (in comparison with the antibody titres in the respective sera). The over-all average geometrical titre (GMT) of antibodies was 1:65 in the eluates and 1:75 in the sera.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
Besnoitia besnoiti is a cyst-forming parasite that has been associated with economic losses in Africa and Europe. Besnoitiosis is considered as a re-emergent disease in the European continent. It is unknown whether cattle are exposed to B. besnoiti in the Americas, thus the aim of this study was to serologically investigate antibodies against B. besnoiti in a total of 2014 cattle serum samples from two states from Brazil. All samples were evaluated by IFAT and part of the positive sera was tested by Western blot (WB) using tachyzoites extracts under non-reducing condition. A total of 3.48% (70/2014) of the tested sera reacted positively by IFAT with titers of 200 (85.7%), 400 (10%) and 800 (4.3%). When 47 positive samples were assessed by WB a range of antigens from 7 to 206 kDa was recognized by the IFAT-positive sera. The results are suggestive of exposure of Brazilian cattle to B. besnoiti due to the titers (≥200) observed for some sera using IFAT. However, the antigens recognized by the IFAT-positive animals did not completely match with the WB patterns previously described by other working groups. It is possible that Brazilian cattle are exposed to B. besnoiti strains with different antigenic composition of those described in the European and African continent. Further studies are needed to confirm the presence of B. besnoiti or other Besnoitia species in Brazilian cattle.  相似文献   

20.
A total of 438 sera from Korean native beef cattle in 9 provinces were tested for Neospora caninum antibodies using an immunofluorescent antibody test (IFAT). Eighteen (4.1%) cattle were positive by IFAT. The titers ranged from 1:200 (10 animals), 1:400 (5 animals), 1:800 (2 animals) to 1:1,600 (1 animal). Although the seroprevalence was slightly higher in Chungnam (8.9%), this was not significantly different from those noted in Kyunggi, Kangwon, Kyungbuk, Kyungnam, and Cheju provinces. Sera obtained from beef cattle in the provinces of Chungbuk, Jeonbuk and Jeonnam were all negative. Neospora positive sera were also tested for anti-Toxoplasma gondii antibodies using a commercial latex agglutination test (LAT). Antibody to T. gondii was detected in only 1 (5.6%) of 18 N. caninum positive sera. These results indicate that N. caninum and T. gondii infection are present at a low level in the Korean native beef cattle.  相似文献   

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