大片形吸虫病早期诊断夹心ELISA方法的建立及应用

为建立一种早期诊断大片形吸虫病的试验方法,本试验对5株分泌抗大片形吸虫分泌排泄抗原(ES)单克隆抗体的杂交瘤细胞进行复苏、制备单克隆抗体,配对筛选出7D1、7D2单克隆抗体,将7D2作为包被抗体,7D1作为酶标抗体,通过条件优化,建立早期诊断大片形吸虫病的夹心ELISA方法。结果显示,当包被抗体稀释度为1:6 400 (0.208 μg/mL)、采用5%脱脂奶粉封闭、酶标记抗体稀释度为1:10 000 (0.200 μg/mL)时,最早可检测到感染此病第7天小鼠的血清循环抗原,其敏感性可达到1:3 200 (0.156 μg/mL),与其他几种寄生虫抗原均无交叉反应,具有较高的特异性和稳定性。本试验成功建立了早期检测大片形吸虫病的夹心ELISA方法,为大片形吸虫病的诊治及开发早期诊断大片形吸虫病的试剂盒奠定了基础,具有临床应用价值。     

片形吸虫分泌排泄抗原和虫体抗原的分析

用牛源肝片吸虫（南京）、牛源大片吸虫（广西）和羊源肝片吸虫（实验感染）制备可溶性虫体抗原（BA）和和分泌排泄抗原（ES），以SDS－PAGE电泳分析比较，结果显示，3株虫体可溶性虫体抗原至少有20条以上的主要蛋白条带，分子量集中于10－90KD之间，它们之间无显著差异，而3株分泌排泄抗原蛋白成分较简单，明显可分的条带不超过5条，分子量集中于10－30KD之间，且均拥有26－28KD的蛋白成分，提示该蛋白应为片形吸虫ES抗原的主要免疫成分。     

间接ELISA检测百色地区牛片形吸虫感染情况

<正>片形吸虫病是危害牛羊等反刍动物的重要寄生虫病之一,且作为一种人兽共患寄生虫病,该病呈全球性分布[1]。多年研究表明[2]我区分布的种类主要为大片形吸虫(F.gigantica)。张为宇等[3]曾计算过一笔经济账,即水牛若感染大片形吸虫250个,每头病牛至少减重8千克,产奶量减少30%。按目前市场平均价格69元/千克来算,每头     

基于GAPDH重组蛋白建立羊肝片吸虫病间接ELISA检测方法

为了建立早期羊肝片吸虫病的血清学快速检测方法,本试验成功克隆并表达肝片吸虫GAPDH重组蛋白,Western blot结果显示,该重组蛋白具有良好的抗原活性。用肝片吸虫GAPDH重组抗原包被,建立肝片吸虫病血清抗体的间接ELISA方法;随后优化反应的最佳血清稀释度和抗原包被量,同时筛选其他反应条件。结果显示,间接ELISA方法批内和批间重复试验的最大变异系数均小于10%,GAPDH重组抗原与华枝睾吸虫、日本血吸虫和捻转血矛线虫阳性血清均无交叉反应。对来自黑龙江省各地区的96份羊血清进行检测,阳性率为16.67%(16/96)。结果表明本试验建立的方法具有良好的敏感性和特异性,能够为早期诊断羊肝片吸虫病提供参考。     

水牛实验感染大片吸虫及ELISA检测特异性抗体的变化

目的　本试验为了对水牛感染大片吸虫的情况进行了解。方法　选 10头 6月龄水牛 ,分成 2组 ,每组 5头 ,A组对照 ,B组试验 ,每头经口感染 2 5 0个大片吸虫囊蚴。结果　水牛感染大片吸虫后的收虫率为 16 .2± 8.0 % ,在感染后第 13～ 14周检出虫卵。抗大片吸虫分泌排泄产物 Ig G水平从感染后第 2周明显升高 ,17周时达到高峰。结论　试验证实水牛对大片吸虫感染很敏感 ,EL ISA检测特异性抗体用于片形吸虫病的早期诊断有一定的意义     

大片吸虫分泌排泄抗原对小鼠肝损伤的研究

为探究大片形吸虫分泌排泄物对小鼠肝脏的影响,将60只雌性昆明小鼠随机分为试验组和对照组各30只。每隔2天注射0.4mg FgESP 200μL,对照组注射PBS 200μL。于首次注射后第10天、4周、7周、14周、18周处死6只小鼠,观察肝脏表观病理变化,制做肝脏HE染色病理切片并测定血清中与肝功能密切相关的ALT、AST、ALP、ALB、GLB等生化指标的变化。肝脏眼观病理变化结果显示,试验组从第4周可见白色点状结节,症状随着时间的延长而加重;肝脏组织病理结果显示,从第2周开始小鼠肝脏出现空泡变性,至第18周出现大量炎性细胞浸润,并伴随轻度肝纤维化;生化指标动态变化结果显示,ALT、AST活性在整个试验进程中出现显著上升(P0.05),ALP活性在第4周~7周明显升高,之后降低(P0.05),ALB和GLB水平在整个试验进程中分别表现为显著下降和显著上升(P0.05),提示肝细胞可能发生变性、坏死导致血清中转氨酶活性升高,蛋白合成能力下降。本研究结果表明大片吸虫分泌排泄抗原(FgESP)可导致小鼠肝损伤,损伤程度随着FgESP的持续注射而加重。     

水牛肝片吸虫病间接ELISA诊断方法的建立及应用

以肝片吸虫的分泌－排泄物作为抗原（ES抗原），建立水牛肝片吸虫病间接ELISA诊断方法，并用此方法与粪便检查法检测江苏和安微2省10县（市）302户的307头水牛的血清和粪便；间接ELISA诊断法的最佳工作条件，每乳包被0．2μg抗原，血清稀释度为1：960，二抗稀释度为1：600。结果粪便检查出虫卵的阳性水牛43头，阳性率为14．01％，其中安徽省为11．61％（18／155），江苏省为16．45％（25／152）；用间接ELISA法检测299头水牛血清，阳性87头，阳性率为29．19％，其中安徽省为23．53％，江苏省为34．92％，两种方法的符合率为86．05％。     

云南省漾濞县牛羊肝片形吸虫病的查治

目的为查清肝片形吸虫在漾濞县的流行情况。方法在该县的苍山西镇的马厂、光明两个行政村进行了牛羊肝片形吸虫病普查。结果两个行政村14个社的牛羊2 025头只,查出阳性病畜363头只,阳性率达17.93%。结论牛羊肝片形吸虫病在漾濞县流行严重,危害很大。     

应用电化学免疫传感器检测大片形吸虫抗原抗体反应的研究

应用电化学免疫传感器，以恒电位法检测了大片形吸虫的抗原抗体反应，结果表明，该传感器可应用于大片形吸虫的抗原抗体反应的检测，阳性血清与阴性血清的电流响应曲线具有明显的离散度；初步试验表明，该法的检测结果相对于ELISA检测结果，其符合率为83．3％；该法还具有操作简便、检测快速、选择性好等特点，测定一个样品用时不到1h，每测一个样品血清用量仅10μl，与羊等多种血清无交叉反应。     

用检测牛乳或血清中抗体的方法普查片形吸虫病

将大片形吸虫分泌排泄产物作为诊断抗原，应用斑点酶联免疫吸附试验和免疫胶体金滴渗法检测牛乳和血清中出现的特异性抗体。测５４头粪便中查出虫卵的牛的乳汁和血清，结果全部呈阳性，符合率１００％。４６头粪检阴笥的牛，检测出２４头牛抗体阳性、提高检出率２４％。这表明，用检测牛乳中抗体的方法诊断片形吸虫感染同检测血清一样具有敏感性高、特异性强、准确性可靠等优点。另外，将待检材料牛乳或血清按１０个一组混合检测，感     

Evaluation of a commercially available enzyme-linked immunosorbent assay for detecting antibodies to Fasciola hepatica and Fasciola gigantica in cattle, sheep and buffaloes in Australia

A commercially available ELISA for detecting antibodies to liver fluke was evaluated for use in Australia. Milk and serum samples from cattle and sheep in which infection with Fasciola hepatica was confirmed by detection of eggs in faeces were used to estimate sensitivity. Similar samples collected from cattle and sheep outside the F. hepatica-endemic area were used to estimate specificity. The ELISA was also evaluated for detecting antibodies to F. hepatica in milk from sheep and antibodies to Fasciola gigantica in sera from cattle and buffaloes, but with small numbers of samples. In cattle, the sensitivity and specificity of the ELISA were 98.2% and 98.3% using serum and 97.7% and 99.3% using milk. In infected herds, 41.4% and 41.5% of animals were positive in the serum and milk ELISAs, respectively, whereas F. hepatica eggs were found in faecal samples from 26.5% of animals. In sheep, the sensitivity of the ELISA was 96.9% and the specificity was 99.4%. In infected flocks, 60.2% of animals were positive in the serum ELISA and F. hepatica eggs were found in faecal samples 52.2% of animals. There was perfect agreement in the ELISA between paired serum and milk samples collected from ewes. The assay detected antibodies in sera from cattle and buffaloes with natural and experimental F. gigantica infections. In the experimentally infected animals, antibodies were detected 2 weeks post-infection. We conclude that the ELISA will be a valuable tool for diagnosing F. hepatica infections in cattle and sheep. The assay may also be useful for diagnosing F. gigantica infections but further studies are required to establish sensitivity and specificity.     

应用LD-PCR法构建大片吸虫成虫cDNA表达文库

为构建大片吸虫成虫cDNA表达文库,用Trizol试剂提取大片吸虫成虫总RNA,经反转录合成cDNA第一链,应用LD-PCR扩增方法,合成双链cDNA。用SfiⅠ内切酶修饰此双链cDNA,使形成两端分别带有SfiⅠA和SfiⅠB的黏性末端。经CHROMA SPIN-400柱纯化,收集400 bp以上的双链cDNA片段,将其连接于带有SfiⅠA和SfiⅠB末端的λTriplEx2噬菌体载体,经体外包装后,以XL1-Blue为受体菌构建cDNA表达文库。经测定,库容量为1.08×106PFU/mL,重组率为96.6%。扩增后的文库滴度为2.41×109PFU/mL,插入片段平均大小约为1 000 bp。这些结果表明已成功构建大片吸虫成虫cDNA表达文库,适合进一步筛选大片吸虫新基因。     

大片形吸虫幼虫的培育及其感染小鼠的研究

本试验旨在培育大片形吸虫囊蚴,着重研究大片形吸虫在中间宿主体内的发育过程和临床病理变化.人工培养和孵化大片形吸虫虫卵,用孵化出来的大片形吸虫毛蚴感染中间宿主小土蜗螺,收集大片形吸虫囊蚴,再用囊蚴感染试验小鼠.结果显示,囊蚴经口感染试验小鼠后1周即可在肝脏找到虫体,幼虫可在小鼠体内发育生存7～8周,随着时间的推移和感染囊蚴数量不同,可给小鼠肝脏造成不同程度的病变,甚至造成死亡.剖检小鼠可见肝脏质地脆,颜色发黄,脾脏肿大等严重病理变化.因此,可利用小鼠作为大片形吸虫幼虫感染的试验动物,进行片形吸虫病的早期诊断、免疫预防和治疗等方面的研究.     

Preparation and Primary Application of Immunity Colloidal Gold Test Strip for Fasciola gigantica

To establish a rapid, simple, sensitive and adapting field application assay for water buffalo Fasciola gigantica, the monoclonal antibodies of hybridoma cell strains 7D1 and 7D4 against excretory-secretary antigen(ES Ag) of Fasciola gigantica were prepared and purified. Meanwhile, the colloidal gold particle was prepared by the sodium cirrate reduction method, then the affinity purified 7D1 monoclone antibodies was labeled with the 30 nm colloidal gold particles. The 7D4 monoclonal antibodies and the goat anti-mouse IgG antibody using as secondary antibodies were coated on the surface of nitrocellulose filter(NC) membrane as the test line (T line) and control line (C line), respectively. The immune colloidal gold test strip was developed by optimizing the experiment conditions. The test results showed the prepared strip had a detecting prescribed minimum of 0.94 μg/mL of Fasciola gigantica excretory-secretary antigen, and it had no any cross reaction with the antigens of Eurytrema pancreaticum, Paramphistome, Chlamydia, Toxoplasma gondii and Trypanosoma evansi. Using the prepared strip to investigate the 334 fresh feces from buffaloes in Guangxi and the positive rate was 38.62%. These results indicated that this strip method was simple, rapid and easy determination, good specificity, high sensitivity, and adapted field application assay for Fasciola gigantica.     

大片形吸虫免疫胶体金检测试纸条的研制及初步应用

为建立一种快速、简便、适应现场应用的水牛大片形吸虫检测方法,本试验利用抗大片形吸虫ES抗原单克隆抗体杂交瘤细胞株7D1和7D4分别制备和纯化得到单克隆抗体7D1和7D4;采用柠檬酸三钠还原法制备颗粒大小为30 nm的胶体金,再用胶体金标记纯化单克隆抗体7D1,在硝酸纤维素膜的质控带和检测带处分别包被羊抗鼠IgG二抗和单克隆抗体7D4,经反应条件优化,组装成了大片形吸虫免疫检测试纸条。经测试该检测试纸条对ES抗原的检测下限为0.94 μg/mL,与胰扩盘吸虫、前后盘吸虫、支原体、弓形虫、伊氏锥虫均无交叉反应,特异性好。采集广西地区334份水牛新鲜粪样并用试纸条检测,阳性率为38.62%。结果表明,试纸条方法操作简单、快速、易于判定,特异性好,敏感性高,适合基层大面积普查和现场检测大片形吸虫。     

大片吸虫组织蛋白酶L1在大肠杆菌中的表达及纯化

利用PCR方法从pET28/FgCL1重组质粒中扩增FgCL1基因,定向克隆至原核表达载体pGEX-4T-2中,构建重组质粒pGEX/FgCL1,将该重组质粒转化大肠杆菌BL21中,转化子经IPTG诱导表达。重组蛋白以包涵体形式存在,相对分子质量为61 000。Western-blot、ELISA试验结果显示,纯化后的重组蛋白能被自然感染大片吸虫的牛血清所识别,表达产物具有良好的抗原性。     

Development and Application of Sandwich ELISA for Diagnosis of Fascioliasis gigantica in Early Stage

To establish a method for the diagnosis of Fascioliasis gigantica in early stage, five hybridoma cell lines were recovered and used for preparation of monoclonal antibodies.7D2 was used as a capture antibody and 7D1 as detection antibody.Coating antibody dilution was 1:6 400 (0.208 μg/mL), 5% nonfat milk was used as blocking solution and detection antibody dilution was 1:10 000 (0.200 μg/mL).The detection limit of the sandwich ELISA was 1:3 200 (0.156 μg/mL), with good specificity and stability, and there was no cross reaction with other kinds of parasite antigen.The results showed that the method provided the important conditions and theoretical basis for the diagnosis of Fascioliasis gigantica in early stage. This would save unnecessary economic losses to the livestock, and it had clinical application value.