猪生长激素ELISA检测体系的建立

本文分别以自制猪生长激素单克隆抗体及兔抗猪生长激素IgG就影响检测elisa(酶联免疫吸附法)体系因素进行探讨,建立了检测猪生长激素的elisa方法。猪生长激素单克隆抗体的最适操作参考值为：单抗最佳包被浓度为3μg/mL,包被条件为4℃过夜,5%羊血清封闭1h,兔抗猪生长激素IgG 最佳工作浓度为2μg/mL。     

转基因棉对棉蚜生长发育及其主要代谢物质含量的影响

近年来,转基因棉田非靶标害虫种群数量呈明显的上升趋势,棉蚜是转Bt(Bacillus thuringiensis)基因棉田发生危害较严重的非靶标刺吸性害虫之一.在实验室内,棉蚜分别用转Bt基因棉和亲本常规棉饲养40代以上,采用酶联免疫法( ELISA)检测转Bt基因棉SGK321上棉蚜体内的Bt蛋白含量,研究转Bt基因...     

酶联免疫吸附法快速检测谷物中的脱氧雪腐镰刀菌烯醇

应用ELISA法快速检测麦类、谷物及其制品中脱氧雪腐镰刀菌烯醇(DON),最低检出限为10μg/L,检测范围为10-1 000μg/L。用10%甲醇水溶液提取含DON的小麦及玉米样品,回收率为86～93%,变异系数为4.1%～17.4%。     

Detection of calves persistently infected with bovine pestivirus in a sample of dairy calves in south-eastern Queensland

Objective To determine the proportion and incidence of calves persistently infected with bovine pestivirus in calves (n = 1521) supplied to the Tick Fever Research Centre and to assess the test regime to detect calves persistently infected with bovine pestivirus.
Design Calves, 1 to 6 weeks old, selected for use in the production of the tick fever vaccine were collected from 21 properties in 56 separate groups between October 1990 and December 1996. Each group was examined for the presence of calves persistently infected with bovine pestivirus.
Procedure All calves were routinely tested for antibody to bovine pestivirus and bovine pestivirus antigen using a serum neutralisation test and an antigen-capture ELISA, respectively. Pooled lymphocyte samples from calves were also monitored for bovine pestivirus by inoculation of sheep. Whole herd testing was carried out in eight herds, using a serum neutralisation test as a screen test followed by an antigen-capture ELISA of cattle with a serum neutralisation test titre of less than 32.
Results Fourteen of the 1521 calves tested (0.9%), were detected as persistently infected and the incidence ranged from 0.0 to 3.0 % per year over 6 years. Persistently infected calves were found in 13 of the 59 groups and originated from 7 of the 21 herds used. In whole herd testing on the properties of origin, cattle persistently infected with bovine pestivirus were detected in four of the eight herds tested
Conclusions The proportion of calves persistently infected with bovine pestivirus is similar to that in other countries and indicates that bovine pestivirus could be a significant cause of economic loss in Australian cattle herds. In detecting calves persistently infected with bovine pestivirus, the combination of sheep inoculation, paired antigen-capture ELISA and serum neutralisation tests appeared to be highly sensitive and specific.     

间接酶联免疫吸附试验检测猪生殖与呼吸系统综合征血清抗体的研究

本研究建立了检测猪生殖与呼吸系统综合征（ＰＲＲＳ）血清抗体的间接酶联免疫吸附试验（ＥＬＩＳＡ），其抗原包被浓度为２μｇ／ｍｌ，血清最适稀释度为１∶１００。试验结果表明：ＥＬＩＳＡ的敏感性高于间接免疫荧光抗体试验（ＩＦＡ），是一种切实可行的诊断方法。     

Sensitivity and specificity of different methods for the isolation of Salmonella from pigs.

Three different selective enrichment media, Rappaport-Vassiliadis broth (RV), selenite broth (SB) and Müller-Kauffmann tetrathionate broth (MKTB), in combination with plating on modified brilliant green agar (BGA), were compared for the isolation of Salmonella from samples of pig feces. These conventional methods were also compared with a new ELISA kit in conjunction with RV and SB enrichment. Of the conventional methods, enrichment in RV had a higher sensitivity and selectivity than SB and MKTB. Recovery of S. typhimurium from MKTB was significantly poorer than recovery of other serotypes. The combination of RV enrichment and ELISA was as good as the conventional method involving RV enrichment, with a similar high sensitivity and specificity.     

Cystic echinococcosis in the Falkland Islands

From 1991 to 1993, an investigation into the epidemiology of cystic echinococcosis (CE) was carried out in the Falkland Islands to evaluate the progress of the hydatid eradication campaign. The prevalence of CE in sheep was assessed using abattoir and farm slaughter data, and the exposure of dogs to the parasite was estimated using immunological techniques. A total of 59 466 sheep was examined at slaughter for E. granulosus and T. hydatigena cysts and the entire dog population of the Falkland Islands (n = 908) was examined by ELISA for the presence of specific serum antibodies to E. granulosus (IgG, IgA and IgE). In addition, a subsample of dogs (n = 464) was tested for the presence of E. granulosus antigens in faeces (copro-antigens). The prevalence of CE in sheep increased significantly during the period of the study from 0.11% in 1991 to 0.47% in 1993. Nineteen (2.1%) of 908 dog sera tested were seropositive, and eight dogs (1.7%) of 464 tested were positive in the copro-antigen assay. The combined use of abattoir surveillance, specific antibody and copro-antigen assay suggested that there were several locations in the Falkland Islands where the life cycle of E. granulosus may still perpetuate. Specific deficiencies in the eradication effort in those locations could be identified through follow-up questionnaires.     

副结核分枝杆菌DNA探针的制备与应用

以溶菌酶、ＳＤＳ、高氯酸钠等处理提取副结核分析杆菌Ｃ２株染色体ＤＮＡ，经限制性内切酶Ｐｓｔ Ｉ消化后，以质粒ｐＢｌｕｅｓｃｒｉｐｔ ＳＫ为载体，通过Ｔ４ＤＮＡ连接酶连接，转入Ｅ。ｃｏｌｉ ＤＨ５ａ受体菌中，构建了副结核菌Ｃ２株的ＤＮＡ基因文库。应用反向杂交试验，从基因文库中筛选出４个重组克隆：ＰＴＰ１２、ＰＴＰ１９、ＰＴＰ３８。对这４个重组克隆进行酶切、电泳分析，结果表明４个插入片段长度分别为：４     

快速ELISA诊断猪旋毛虫病的研究

在快速间接ELISA中将被检血清样品和酶结合物一起保温。既简化了操作步骤,又比常规ELISA缩短了30～90分钟。通过对猪旋毛虫病阴阳性血清检测,表明该方法敏感性为93.62％,特异性为96.88％。为猪旋毛虫病捉供了一种快速诊断方法。     

Toxoplasma gondii in Switzerland: a serosurvey based on meat juice analysis of slaughtered pigs, wild boar, sheep and cattle

Toxoplasmosis is one of the most important zoonotic diseases worldwide and is caused by the protozoan Toxoplasma gondii. Besides vertical infection during pregnancy, humans can get infected post-natally either by peroral uptake of sporulated Toxoplasma oocysts or by ingestion of tissue cysts upon consumption of raw or undercooked meat. The aim of this study was to approximate the risk of human infection via meat consumption by estimating the seroprevalence of T. gondii in slaughtered animals in Switzerland and to compare data with prevalences assessed 10 years ago. The study included pigs, cattle, sheep and wild boar of different age groups and housing conditions whenever possible and applicable. A P-30-ELISA was used to detect T. gondii-specific antibodies and to determine seroprevalences in meat juice of slaughtered animals. A total of 270 domestic pigs (120 adults, 50 finishing, 100 free-ranging animals), 150 wild boars, 250 sheep (150 adults, 100 lambs) and 406 cattle (47 calves, 129 heifers, 100 bulls, 130 adult cows) were tested. Seropositivity increased with the age of the assessed animals. Independent of the age-group, the overall seroprevalence was lowest in wild boars (6.7%), followed by pigs (23.3%), cattle (45.6%) and sheep (61.6%), respectively. Conventional fattening pigs and free-ranging pigs surprisingly had comparable seroprevalences (14.0% and 13.0%, respectively). Unlike in other European countries, where generally a decrease in the number of seropositive animals had been observed, we found that the prevalence of seropositive animals, when compared with that of 10 years ago, had increased for most species/age groups. Conclusively, the results demonstrated a high seroprevalence of T. gondii in animals slaughtered for meat production and revealed that increasing age of the animals is a more important risk factor than housing conditions in Switzerland.