首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 390 毫秒
1.
本研究首次以葡聚糖G200部分纯化东毕吸虫成虫抗原,用751分光光度计测各管的OD值,结果共出现四个洗脱峰,其中以第一峰峰值最高,蛋白浓度为1.329毫克/毫升。将纯化的抗原与东毕吸虫阳性血清,阴性血清采用IHA的方法测定其抗原的特异性与敏感性。结果表明:部分纯化抗原在IHA试验中具有特异性强和敏感性高的特点。  相似文献   

2.
为了探明东毕吸虫成虫可溶性抗原的多肽组分,供今后在免疫诊断和防治东毕吸虫的应用,本试验应用SDS- PAGE首次对绒山羊体内寄生的土耳其斯坦东毕吸虫成虫可溶性抗原的多肽组分进行了分析。结果表明该抗原有17 条多肽带,其分子量范围25~93KD.其中主带7 条,分别为29、30、38、40、67、78、91KD。本试验初步阐明了土耳其斯坦东毕吸虫成虫抗原的多肽组分,为进一步对该病免疫诊断用抗原的分离、纯化,提高抗原的敏感性和特异性奠定了基础  相似文献   

3.
用蔗糖不连续梯度纯化的减蛋综合征*(EDS-76)病毒包被ELISA板,建立了检测EDS-76抗体的间接ELISA法。经测定,抗原最适包被浓度为1μg/mL,待检血清最佳稀释度为1:200,以OD490〉0.3,P/N〉2.1判为阳性结果。对4个鸡场的120份鸡血清进行检测,阳性率分别为0,43.33%,80.00%和93.33%。  相似文献   

4.
建立了辣根过氧化物酶标记兔抗鸡IgG检测鸡传染性支气管炎抗体的间接EISA法,其抗原包被浓度为4mg/L,待检血清与酶结合物的最佳稀释度各为1:80,酶结合物,抗原抗体的作用时间分别为60min,30min,封闭液的浓度和作用时间分别为1%和60min,OD值大于0.287的判为阳性。用此法检测经IBV灭活苗免疫鸡所产蛋孵出的雏鸡的母原抗体,OD值的P/N值为6.0,15d后降至2.0以下。检测1  相似文献   

5.
为了探明东毕吸虫成虫可溶性抗原的多肽组分,供今后在免疫诊断和防治东毕吸虫的应用,本试验应用SDS-PAGE首次对绒山羊体内寄生的土耳其斯坦东毕吸虫成虫可溶性抗原的多肽组进行了分析。结果表明该抗原有17条多肽带,其分子量范围25-93KD。其中主带7条,分别为29,30,38,40,67,78,91KD。  相似文献   

6.
用东毕吸虫成虫,经葡聚糖凝胶G—100层析柱制备纯化抗原,应用ELISA间接法检测自然感染东毕吸虫绵羊的抗体,同时,配合沉淀法、孵化法和全身剖检法进行检查,显示阳性符合率为98.4%,阴性符合率为95%;除与肝片吸虫阳性血清有4.8%的交叉反应外,未发现与矛形双腔吸虫阳性血清和前后盘吸虫阳性血清有交叉反应;ELISA的阳性检出率高于沉淀法和孵化法;并证明东毕吸虫感染强度与血清抗体无相关关系。  相似文献   

7.
异源抗原在建立ELISA检测传染性法氏囊病毒抗体中的应用   总被引:4,自引:0,他引:4  
本文报告采用vero细胞增殖的IBDV抗原建立了间接酶联免疫吸附试验(ELISA),用于定量检测鸡传染性法氏囊病毒(IBDV)抗体。该法快速、敏感性高、特异性强、重复性好。同时,通过30份血清样品ELISA效价(ET)的对数值(logET)与血清P/N值(待检血清OD值与阴性血清OD值之比)的线性回归分析,得直线方程y=3.0589+0.0739x(r=0.9174),从而血清样品的ET可通过血清单一稀释度的P/N值来计算。用不同来源抗原作ELISA表明,从vero细胞增殖的抗原比从鸡胚成纤维(CEF)细胞增殖的抗原可提高检测血清OD值近20%,表现出异源抗原具有更高的特异性  相似文献   

8.
将pGEM—TM质粒上的土耳其斯坦东毕吸虫原肌球蛋白(TM)基因片段亚克隆至原核表达载体pET28a(+),重组的pET28-TM在大肠埃希氏菌BL21(DE3)中经1mmol/LIPTG诱导表达出-37.5ku的融合蛋白。该蛋白经Ni—NTA亲和层析柱纯化,SDS—PAGE检测,出现与目的蛋白大小一致的单一条带。Western-blotting检测结果表明,纯化的蛋白可被自然感染东毕吸虫的山羊血清识别,这为进一步研究东毕吸虫基因工程疫苗奠定了基础。  相似文献   

9.
在用ELISA诊断西宁地区猪囊虫病,以OD值的+3SD判定结果时,比较了不同血样(滤纸片干血与血清)、不同反应温度(50℃与室温)对反应结果的影响。结果:对照间OD值呈正相关关系,相关系数分别为0.8847和0.9667,对照间阳性检出率基本一致,符合率分别为91.20%和95.90%;使用不同保存期的已包被反应板时,虽然对照间OD值呈正相关关系(r=0.8450)但用保存期4个月的包被反应板降低了阳性检出率,影响其符合率。  相似文献   

10.
大庆市羊东毕吸虫病流行病学调查   总被引:1,自引:0,他引:1  
对大庆市羊东毕吸虫病的流行病学进行了调查研究。结果表明,大庆有3种东毕吸虫,即程氏东毕吸虫(O.cheni)、土耳其斯坦东毕吸虫(O.turkestanica)和土耳斯坦东毕吸虫结节变种(O.turkestanican var.thuberculata);中间宿主螺类有1种,即卵萝卜螺;东毕吸虫病在大庆分布很广,所调查的4区2县均有发生,羊东毕吸虫平均感染率分别为50.33%,平均死亡率为21.12%,大庆羊急性病例发病时间为8月上旬至10月下旬,慢性病例为11月上旬至翌年2月中旬。  相似文献   

11.
以纯化的PRV抗原为包被抗原,优化ELISA反应条件,建立了可检测PRV血清抗体的间接ELISA诊断方法。标定抗原的最佳包被量为0.802μg/mL,血清样品最佳稀释度为1∶100,最佳作用时间为60min,判定标准为OD 450nm值大于0.357为阳性,小于0.296为阴性,在0.296与0.357之间为可疑。该方法检测其他6种常见猪病病毒(CSFV、PCV-2、PRRSV、PPV、JEV、TGEV)的阳性血清均为阴性;与商品化ELISA试剂盒相比较,符合率、敏感性和特异性分别为90.0%、87.1%、92.3%。本研究建立的PRV间接ELISA抗体检测方法具有良好的重复性、敏感性和特异性,为PRV免疫猪群抗体监测、快速诊断和PR流行病学调查提供一种快速、简便的血清学诊断方法。  相似文献   

12.
Capsular polysaccharide antigens of serotypes 1, 2, 5 and 7 of Actinobacillus pleuropneumoniae were used in enzyme-linked immunosorbent assays (ELISAs) to test sera from experimentally infected and field pigs. Specific reactions were found in sera of experimental pigs with antigens of serotypes 1, 5 and 7 whereas the serotype 2 antigen was cross-reactive. A 1:200 serum dilution was used for testing of 300 sera from 21 swine herds in southern Ontario. Cases of pleuropneumonia had occurred in 11 of these herds, but not in the others. The negative cut-off value was the mean optical density at 405 nm (OD405) + three standard deviations (SD) for 16 negative reference sera. Sera from four pigs naturally infected with Actinobacillus suis were tested and found to react to varying degrees with each of the antigens. Therefore a second cut-off value was determined as the mean OD405 + 2 SD for the A. suis sera. Sera which, in the ELISA produced OD readings above the latter cut-off were considered positive for antibodies to A. pleuropneumoniae; those which were lower than the former cut-off were considered negative. Readings between the two cut-off values may have been due to low positive titers or cross-reactivity, possibly with A. suis, and could not be used to predict pleuropneumonia. Of the pleuropneumonia-free herds, none had positive reactors to serotypes 5 or 7, whereas one and two herds had positive reactors to serotypes 1 and 2, respectively. Of the pleuropneumonia positive herds, six had positive reactors to serotype 1, one to serotype 2, four to serotype 5, and eight to serotype 7.  相似文献   

13.
Li C  Cheng A  Wang M  Zhang N  Shen C  Yang J  Zhu D  Jia R  Luo Q  Chen X 《Avian diseases》2010,54(4):1270-1274
An indirect enzyme-linked immunosorbent assay (iELISA) was developed for detecting antibody to duck swollen head hemorrhagic disease virus (DSHDV) using purified whole virus by sucrose density gradient ultracentrifugation as a coating antigen. Antiserum against DSHDV strains HY-99 (hyperimmume serum) was prepared in 30-day-old ducks by vaccination with inactivated DSHDV and used as positive sera. The iELISA test was optimized with different reagents or dilutions. The validation results showed that this assay was only specific for antibodies against duck viral swollen head hemorrhagic disease. The OD450 value for positive serum diluted 1:800 was also determined to be greater than the positive threshold. The highest coefficient of variation value was 3.66% for the intra-assay and 5.79% for the interassay, which were all less than 10%. This assay has been successfully applied to the examination of the duck sera clinically. These results in this study indicate that the newly-developed iELISA offers a precise, specific, sensitive, and reproducible means of measuring DSHDV antibodies in duck sera.  相似文献   

14.
Serial dilution and single dilution enzyme linked immunosorbent assays (ELISA) were standardised and their sensitivity and specificity were compared for serodiagnosis of Babesia equi infection. The antibody titres of 24 donkey sera of known identity were determined separately by serial dilution ELISA using three different B. equi antigens namely whole merozoite (WM), cell membrane (CM) and high speed supernatant (HSS). The ratios of the optical density (OD) of known positive and known negative sera at different serum dilutions were calculated and termed as the positive/negative (P/N) ratio. The coefficients of correlation (r) were calculated between the P/N ratios at different dilutions of sera and the log10 antibody titres of the same sera were ascertained by serial dilution ELISA. The highest value of 'r' was obtained at a serum dilution of 1:200. From log10 antibody titre of sera (y) and their P/N ratio at a dilution of 1:200 (x), regression equations (y = a + bx) were calculated separately for the three antigens. Test sera were diluted to 1:200, their OD were read in duplicate wells and were converted to the P/N ratio. Antibody titres were predicted from the P/N ratio using a regression equation separately for the three antigens. Titres obtained by both ELISAs were not significantly different from each other, thus confirming that single dilution ELISA could be successfully used to replace conventional serial dilution ELISA. The sensitivity, specificity and predictive value of single dilution ELISA was validated statistically using 42 B. equi disease-positive sera and 106 B. equi disease-negative sera. The WM antigen was found to be the most sensitive with a higher predictive value for negative test sera as compared to the CM or HSS antigens. Sera positive for other equine infections including Babesia caballi showed no cross-reaction with the three B. equi antigens in ELISA, thus the test was immunologically specific. Antibody titres of 109 unknown field donkey/horse sera obtained by serial and single dilution ELISA using the WM antigen did not show any significant difference. Since the single dilution ELISA was found to be more economical, convenient, sensitive, specific than the serial dilution ELISA and has a high predictive value, it is suitable for use in sero-epidemiological studies on B. equi infections in the field.  相似文献   

15.
为检测猪血清中猪流行性腹泻病毒(PEDV)抗体水平,以纯化的PEDV作为包被抗原,优化ELISA反应条件,建立了检测PEDV血清IgG抗体的诊断方法:当血清OD_(450nm)值0.31时,判定阳性;当OD_(450nm)值小于0.26时,判定阴性;当OD_(450nm)值介于两者之间判定可疑。结果表明,试验建立的ELISA抗体检测方法可用于检测猪血清中猪流行腹泻病毒抗体、监测猪流行腹泻病的流行情况和评价相关疫苗的免疫效果。  相似文献   

16.
An antigen was isolated from the protoplasm of Mycobacterium paratuberculosis by a combination of gel filtration, ion exchange, and affinity chromatography. The purified antigen constituted 7.8% of the total protein in the protoplasm. The specificity and sensitivity of the enzyme-linked immunosorbent assay (ELISA) for paratuberculosis, using the purified antigen, were evaluated with sera from 104 cattle which were examined (surveyed) for M paratuberculosis infection by fecal cultural technique. The ELISA was positive in 50 of 60 infected animals. Five of 44 noninfected animals were also test-positive. When a crude protoplasmic extract was used as antigen in the ELISA, sera from 37 infected and from 18 noninfected animals were test-positive. Cross-reactions were encountered in both complement-fixation test and the ELISA between crude or partially purified M paratuberculosis antigens and antisera to Nocardia asteroides, M avium, M phlei, and M fortuitum. The purified antigen gave no complement-fixation reaction with any of these antisera. In the ELISA, cross-reaction was not found when purified antigen was used and the sera were screened at 1:40 dilution.  相似文献   

17.
Serum samples from 61 dogs and 49 cats were screened for circulating antibodies against Helicobacter felis by an enzyme-linked immunosorbent assay (ELISA) using sonicated bacteria as an antigen. To improve the specificity of the ELISA, sera were absorbed with Campylobacter jejuni subsp. jejuni H. pylori as well as H. felis. Sera from 26 dogs (43%) and 19 cats (39%) revealed clear positive absorbance readings determined as an optical density (OD) that was statistically significant above the OD mean value [P < 0.025 (one-tailed); log10]. The absorbance pattern of ELISA-positive sera corresponded to results obtained with bovine and human reference sera. Furthermore, a correlation between the immune response and results from histopathological examination of gastric specimens from 22 dogs was demonstrated. It could be shown that antibodies against H. felis in sera of cats and dogs can easily be detected using an ELISA. The diagnostic value of this test must be evaluated in further investigations.  相似文献   

18.
以纯化的大肠埃希菌K88菌毛蛋白为包被抗原,建立了检测大肠埃希菌K88IgG抗体的间接ELISA方法。确定了间接ELISA的最适反应条件,即最佳抗原包被浓度为1μg/mL,兔抗体稀释倍数为1∶10,猪抗体稀释倍数为1∶100,确定最佳封闭液为50g/L脱脂奶粉,最佳封闭时间为0.5h,血清反应时间0.5h,二抗反应时间1h,底物室温反应时间为15min,阴阳性临界值兔血清为0.33、猪血清为0.45。证实该间接PPA-ELISA方法特异性强、重复性好、敏感度高,可以作为疫苗效力检验和流行病学调查的参考方法。  相似文献   

19.
设计一对特异性引物扩增出鸭肠炎病毒(DEV)核衣壳蛋白(NP)基因,并将其定向插入到原核表达载体pET32a上,构建了NP基因的原核表达载体pET-NP;将重组载体pET-NP转化表达宿主菌BL21后,经SDS-PAGE分离后行Western blot显示,获得的表达产物具有良好的免疫原性;应用His.Bind亲和层析柱纯化重组NP蛋白,并以此作为包被抗原,初步建立了检测鸭肠炎病毒抗体的iNP-ELISA;经方阵滴定确定,重组蛋白抗原的最佳包被浓度为5.0μg/L,血清最佳稀释度为1∶80,阳性判定标准为:待检血清OD405值≥1.2,且待检血清OD405和阴性血清OD405的比值≥2.0;应用iNP-ELISA对450份鸭血清样本进行检测,结果iNP-ELISA与全病毒包被的iDEV-ELISA符合率达90.9%。  相似文献   

20.
为确定猪支原体在临床的感染情况和进行血清流行病学调查,本研究以原核表达纯化的猪支原体MSG1重组蛋白为包被抗原,建立了检测猪支原体的间接ELISA诊断方法。通过对ELISA反应一系列条件的优化,确定了最佳抗原包被浓度为0.5μg/mL;最佳封闭条件为用1%BSA37℃温箱内封闭2 h;血清最适稀释度为1∶200,作用时间为1.5 h;酶标二抗最适稀释度为1∶15 000,最适作用时间为1 h;最后37℃显色15 m in。判定标准为OD450≥0.239时判为阳性,OD450<0.198时判为阴性,0.198≤OD450<0.239时判为可疑。敏感性、特异性和可重复性试验证明,该检测方法敏感性高、特异性强和可重复性好。该研究表明建立的间接ELISA方法为猪支原体的检测和区域流行病学调查提供了一种快速简便的血清学诊断方法。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号