新城疫病毒胶体金免疫层析试纸条的制备

为了建立一种简便、快速检测新城疫病毒（Newcastle disease virus, NDV）的方法,本试验采用柠檬酸三钠还原法制备胶体金颗粒,标记NDV单克隆抗体6C4制备免疫检测探针。在硝酸纤维素膜上,用微定量喷头喷好1条病毒检测线（T线）和1条羊抗鼠抗体质控线（C线）,制备免疫层析检测试纸条,使用该制备好的检测试纸条可在10 min内检测出新城疫病毒。试纸条检测NDV的灵敏度比HA试验结果提高8倍,与禽流感病毒未出现交叉反应,用缓冲液对照测试,结果为阴性,在密封、干燥、低温的条件下,试纸条的灵敏性与特异性没有明显变化。本研究建立的NDV免疫层析检测法具有特异、灵敏、稳定、操作简单等特点,符合现场快速检测的要求。     

半定量检测新城疫抗体胶体金试纸条的研制

为建立半定量快速检测新城疫抗体方法，本研究利用柠檬酸钠还原氯金酸，形成胶体金颗粒，应用直径20nm的胶体金颗粒标记新城疫抗原，制作了半定量快速测定新城疫抗体的免疫胶体金试纸条。用试纸条检测60份样品，检测结果与血凝抑制试验（HI）法测得结果的符合率为93．8％，最小检测HI滴度为410g2，与其他病毒的阳性血清没有交叉反应，且室温下有效保存期为3个月。试纸条应用方便、快速，适合临床推广以及流行病学调查。     

胶体金免疫层析试纸条法与血凝抑制试验、琼脂扩散法检测禽流感病毒抗体的比较

用本实验室建立的胶体金免疫层析试纸条法检测了鸡血清中的禽流感病毒抗体，并与传统的血凝抑制试验、琼脂扩散法检测结果进行了比较。结果表明，胶体金免疫层析试纸条具有特异性强、灵敏度高、方法简便、快速等优点，适合于鸡禽流感病毒抗体的现场快速检测。     

禽流感病毒荧光免疫层析检测试纸条的研制

禽流感是重要的人兽共患病,建立现场快速灵敏的检测方法是防控其发生和流行的前提和基础。本研究采用不同亚型流感毒株交叉免疫小鼠法来免疫小鼠,通过多个亚型的NP表达蛋白来筛选杂交瘤阳性细胞株,获得分泌针对NP蛋白单克隆抗体的杂交瘤细胞4株。通过抗体的两两配对,基于荧光量子点作为免疫层析抗体的标记探针,借助免疫层析试纸条双抗夹心法原理,筛选出了适用于免疫层析的两株单克隆抗体,研制了禽流感病毒(Avian influenza virus, AIV )荧光免疫层析检测试纸条[A lateral-flow immunoassay strip with quantum dots(QDs)against AIV , AIV -QD-LFIA],并对该试纸条进行了特异性、敏感性、可重复性及可靠性分析。试验结果显示:本研究所建立的 AIV -QD-LFIA试纸条检测禽流感标准抗原H5N1-HK的敏感性达到104 EID50 ,检测标准抗原H9N2-HK的灵敏度为102 EID50 ,比商品化的禽流感病毒抗原检测卡灵敏度高100倍,比国家标准实时荧光RT-PCR(rRT-PCR)灵敏度低约100倍;可特异性地检测出H5亚型、H7亚型、H9亚型、H1亚型、H3亚型等A型流感病毒,与 IBV 、 NDV 等常见禽呼吸道传染病病原无交叉反应,且经过了国家流感中心标准样本盘的样品测试,特异性强;同时该法具有良好重复性,连续4周检测20个样品重复结果均为阳性;小规模田间试验显示该法用于禽流感病毒的普查监测结果可靠。可见本研究所建立的 AIV -QD-LFIA试纸条可满足禽流感病毒快速、高灵敏的检测需求,具有广阔的应用空间。     

弓形虫单克隆抗体的制备及胶体金免疫层析试纸条研制

弓形虫病(Toxoplasmosis)是由刚地弓形虫(Toxoplasma gondii,TOX)引起的一种重要人兽共患寄生虫病,该虫是一种可寄生于有核细胞的原虫。当前对弓形虫病的诊断和治疗虽已有一些方法,但均不够理想。本文就该病的免疫学诊断方法的研究进展加以概述,以研究SAG2为检测抗原,以制备弓形虫SAG2蛋白的单克隆抗体和免疫胶体金试纸条为核心,建立一种快速、特异、便捷的检测方法,为我国弓形虫病的诊断与防治、弓形虫与宿主关系、以及弓形虫的分子生物学等研究奠定良好基础。     

检测犬瘟热病毒的单克隆抗体胶体金试纸条的制备

将从水貂中分离的犬瘟热病毒（Canine distemper virus,CDV）HB株经培养和纯化后免疫小鼠,制备分泌抗CDV-HB的杂交瘤细胞株,分别命名为2E1和7F3,ELISA测定腹水效价均大于107。亚类鉴定结果表明单抗2E1的分子亚类为IgM,7F3的分子亚类为IgG1,间接免疫荧光试验表明,这两株单抗均可以与CDV-HB特异性结合。采用柠檬酸三钠还原法制备胶体金颗粒并标记2E1单克隆抗体,获得检测貂犬瘟热病毒抗原的胶体金免疫层析试纸,且鉴定证明制备的检测CDV的胶体金试纸条具有良好的的特异性。     

口蹄疫病毒抗原胶体金试纸条的研究

利用单克隆抗体技术制备抗口蹄疫病毒的单克隆抗体,特异性试验表明其只与O、A、Asia 1型3种血清型FMDV抗原结合。进而采用胶体金标记技术,以胶体金标记的抗口蹄疫病毒单克隆抗体、多克隆血清抗体和葡萄球菌A蛋白为主要材料,研制口蹄疫快速检测试纸条。该试纸条检测O、A、Asia 1型3种血清型灭活口蹄疫病毒均为阳性,检测水疱性口炎病毒、猪水疱病病毒、蓝舌病病毒、猪蓝耳病病毒4种灭活抗原及小反刍兽疫病毒疫苗株均为阴性,试验结果与口蹄疫实时荧光定量RT-PCR方法的完全一致,表明其具有良好的特异性。敏感性试验结果是,试纸条的检测极限为1∶160稀释的样品,其敏感性相当于实时荧光定量RT-PCR方法的1/64。由于试纸条具有操作方便、检测快速等优点,因此该试纸条可以用于大量临床样品的快速检测和现场检测。     

牛副结核胶体金免疫层析试纸条的研制

将提纯的牛副结核分支杆菌重组蛋白MAP0862-2154c作为硝酸纤维素膜检测线的包被抗原,兔抗羊IgG作为硝酸纤维素膜质控线的包被抗体,金标羊抗牛IgG点喷到玻璃纤维素膜上,制成用于检测牛副结核抗体胶体金免疫层析试纸条。用牛的副结核标准阳性血清与检测试纸条反应,在检测线处出现红色反应带,而滴加阴性血清的试纸条检测线处未出现反应条带,上述2种血清在质控线处均出现红色反应条带;试纸条可检出牛副结核抗体的最低抗原包被浓度为400μg/mL;试纸条不与牛结核病、牛布鲁氏菌病的阳性血清发生反应;试纸条37℃保存9d后的检验结果与4℃保存的检验结果相同。所制备的试纸条具有灵敏、特异的优点,稳定性良好;10min左右即出结果,操作简便,可用于临床诊断。     

硝基呋喃类药物胶体金免疫层析试纸条的研制

介绍了检测饲料中硝基呋喃类药物胶体金试纸条的研制方法,主要包括胶体金的制备、金标抗体的制备及试纸条的组装和性能测试等内容。试纸条能同时检测饲料中8种硝基呋喃类药物:呋喃西林、呋喃唑酮、呋喃它酮、呋喃妥因、硝呋索尔、呋喃苯烯酸钠、硝呋烯腙、硝呋酚酰肼,检测限范围为0.2⁰.8μg/g。因此,该试纸条可应用于饲料中呋喃类药物的快速检测和现场筛查,具有较高的市场应用前景。     

犬细小病毒胶体金检测试纸条的制备与初步评价

为快速检测及诊断犬细小病毒及其引起的传染性疾病,应用胶体金免疫层析技术．采用柠檬酸三钠还原法制备25nm的胶体金颗粒,标记抗犬细小病毒单克隆抗体CPV—F1株后包被于玻璃纤维膜作为金标垫,在硝酸纤维素膜上分别包被羊抗小鼠IgG二抗和抗犬细小病毒单克隆抗体CPV—B6株作为质控线和检测线,将吸水垫、硝酸纤维素膜、金标垫和样品垫分别粘贴于背衬板上制成犬细小病毒抗原胶体金检测试纸条。特异性试验及与血凝试验的对比结果表明,该试纸条具有良好的特异性和敏感性,与进口产品的总符合率为98％。本研究为进一步研发犬细小病毒检测试纸奠定了基础。     

表达H9亚型禽流感病毒HA基因的重组新城疫病毒的拯救

对现地分离的4株H9亚型禽流感病毒HA基因进行序列测定,选取其中1株在新城疫病毒 La Sota弱毒疫苗株反向遗传操作系统的基础上,构建了表达H9亚型禽流感病毒野生型HA基因的重组新城疫病毒基因组cDNA克隆,经间接免疫荧光和RT-PCR鉴定,结果表明:拯救重组病毒为rL-H9HA;重组病毒MDT≥168 h,ICPI和IVPI均为0,与亲本疫苗株La Sota具有相似的生长特性;重组病毒保持了La Sota弱毒疫苗亲本毒株对鸡胚良好的高滴度生长适应和低致病特性,具有作为同时预防H9亚型禽流感和新城疫的双价苗的应用前景.     

Development of an antigen-ELISA and a colloidal gold–based immunochromatographic strip based on monoclonal antibodies for detection of avian influenza A(H5) viruses

Avian influenza A(H5) viruses (avian IAVs) pose a major threat to the economy and public health. We developed an antigen-ELISA (ag-ELISA) and a colloidal gold–based immunochromatographic strip for the rapid detection of avian A(H5) viruses. Both detection methods displayed no cross-reactivity with other viruses (e.g., other avian IAVs, infectious bursal disease virus, Newcastle disease virus, infectious bronchitis virus, avian paramyxovirus). The ag-ELISA was sensitive down to 0.5 hemagglutinin (HA) units/100 µL of avian A(H5) viruses and 7.5 ng/mL of purified H5 HA proteins. The immunochromatographic strip was sensitive down to 1 HA unit/100 µL of avian A(H5) viruses. Both detection methods exhibited good reproducibility with CVs < 10%. For 200 random poultry samples, the sensitivity and specificity of the ag-ELISA were 92.6% and 98.8%, respectively, and for test strips were 88.9% and 98.3%, respectively. Both detection methods displayed high specificity, sensitivity, and stability, making them suitable for rapid detection and field investigation of avian A(H5) viruses.     

鸡新城疫-鸡传染性支气管炎-禽流感-产蛋下降综合征四联灭活油乳剂疫苗的研制与免疫试验

用鸡新城疫La Sota株,鸡传染性支气管炎H120株,产蛋下降综合征127株和禽流感病毒HB1(H9N2)株做为抗原制成油乳剂灭活联苗,并对其进行了物理性状、纯净、安全性、灭活效果、保存期和免疫效力等方面的检验.证明所制备疫苗完全符合质量标准;鸡体对该疫苗4种抗原均产生了良好的免疫应答;攻毒试验证明,免疫鸡能良好地抵抗同种强毒的攻击;所制备疫苗于2～8℃保存12个月后,其免疫效力没有下降.     

禽流感病毒一步法RT-PCR检测方法的建立

为了能快速准确地对禽流感进行病原学诊断，根据流感病毒的M基因序列，在保守区内用Olig04．0软件设计了1对引物，建立了一步法RT—PCR诊断方法，其目的片段大小为229bp。通过对不同稀释倍数的H5亚型禽流感病毒尿囊液和棉拭子浸出液进行检测，结果显示，病毒尿囊液的最低检出稀释度为1：10^4；阳性棉拭子的最低检出稀释度为1：2^3。用病毒分离法和一步法RT—PCR同时检测人工感染鸡不同脏器、口咽及泄殖腔棉拭子样品，二者符合率为100％，但前者的检测灵敏度比后者高10～100倍。用该方法检测H1～H15亚型禽流感病毒和鸡新城疫病毒等其他14种禽病病原，所有禽流感病毒均有229bp的目的条带出现，而其他14种禽病病原均无目的条带出现，表明该方法的特异性好。     

Evaluation of a competitive ELISA for antibody detection against avian influenza virus

Active serologic surveillance is necessary to control the spread of the avian influenza virus (AIV). In this study, we evaluated a commercially-available cELISA in terms of its ability to detect AIV antibodies in the sera of 3,358 animals from twelve species. cELISA detected antibodies against reference H1- through H15-subtype AIV strains without cross reactivity. Furthermore, the cELISA was able to detect antibodies produced following a challenge of the AIV H9N2 subtype in chickens, or following vaccination of the AIV H9 or H5 subtypes in chickens, ducks and geese. Next, we tested the sensitivity and specificity of the cELISA with sera from twelve different animal species, and compared these results with those obtained by the hemagglutination-inhibition (HI) test, the "gold standard" in AIV sera surveillance, a second commercially-available cELISA (IZS ELISA), or the agar gel precipitation (AGP) test. Compared with the HI test, the sensitivities and specificities of cELISA were 95% and 96% in chicken, 86% and 88% in duck, 97% and 100% in turkey, 100% and 87% in goose, and 91% and 97% in swine, respectively. The sensitivities and specificities of the cELISA in this study were higher than those of IZS ELISA for the duck, turkey, goose, and grey partridge sera samples. The results of AGP test against duck and turkey sera also showed significant correlation with the results of cELISA (R-value >0.9). In terms of flock sensitivity, the cELISA correlated better with the HI test than with commercially-available indirect ELISAs, with 100% flock sensitivity.     

抗H5亚型禽流感病毒血凝素蛋白特异性单克隆抗体的研制及鉴定

以抗H5亚型禽流感病毒（AIV）JSD株鸡胚尿囊液免疫8周龄BALB/c小鼠,第4次免疫后取其脾淋巴细胞与SP2/0-Ag-14骨髓瘤细胞融合,用血凝抑制试验（HI）对杂交瘤进行筛选,经3次亚克隆后,共获得4株针对血凝素（HA）蛋白的特异性单克隆抗体,分别命名为：2D2、2C8、3D3和3D11。该4株单抗的小鼠腹水的HI效价在2^13～2^15,ELISA效价为1.2×10^5～5.1×10^5。亚类鉴定结果表明,2D2和3D11属于IgG1,2C8属于IgG3,3D3属于IgG2a亚类;特异性试验结果表明,上述4株单抗仅与H5 AIV毒株发生特异性反应,而不与其他亚型AIV以及NDV、IBV和EDSV-76等病毒反应;鸡胚中和试验结果显示,4株单抗均具有较好的中和活性。本研究成功获得4株针对H5 AIVHA蛋白的特异性单抗,为临床H5 AIV的血清学监测及鉴定提供了必需的试剂。     

禽流感抗原快速检测试纸条的研究

应用胶体金标记技术(Immunogold Labelling Technique)与免疫层析技术,在玻璃纤维膜和硝酸纤维膜的检测线(T)和对照线(C)上分别喷上胶体金AIV单克隆抗体(Ab2)偶联物和AIV单克隆抗体(Ab2)-羊抗鼠IgG多克隆抗体,制成禽流感抗原检测试纸条。用该试纸检测“AIV琼扩抗原”、“AIV H5N1抗原”、“AIV H7N1抗原”、“AIV H9N1抗原”均显阳性,而对禽源性的其它病毒抗原均显阴性;本试纸与韩国产“禽流感检测试纸条”同时检测相同的样品,结果完全一致,且具有很好的线性(敏感度),是一种微量、特异、快速、简便和结果容易判定的新的检测方法,可作为检测机构和养禽场检测初筛禽流感时使用。     

Influences of major histocompatibility complex class I haplotypes on avian influenza virus disease traits in Thai indigenous chickens

Natural infections with influenza viruses have been reported in a variety of animal species including humans, pigs, horses, sea mammals, mustelids and birds. Occasionally, devastating pandemics occur in domestic chickens (broiler and layers) and in humans. From November 2003 to March 2004 in many countries in Asia, there were outbreaks of H5N1 avian influenza virus, causing death of infected patients, and devastating the poultry industry. Some groups of Thai indigenous chickens survived and were therefore classified as resistant. These traits were related to immunogenetics, in particular, the major histocompatibility complex (MHC) class I and class II molecules. The chicken MHC class I were investigated as candidate genes for avian influenza virus disease resistance. Seven hundred and thirty Thai indigenous chickens from smallholder farms in the rural area of avian influenza virus disease outbreaks in the central part of Thailand were used in the present study. They were separated into two groups, 340 surviving chickens and 390 dead chickens (resistant and susceptible). Genomic DNA were precipitated from blood samples and feathers. The DNA were used to amplify the MHC class I gene. Data were analyzed using χ² analysis to test significant differences of influences of MHC class I haplotypes on avian influenza virus disease traits. The results represented nine MHC class I haplotypes: A1, B12, B13, B15, B19, B21, B2, B6, and BA12, and included 10 of their heterozygotes. The homozygous B21 from these collected samples had a 100% survival rate and they were the major survival group. In addition, the heterozygous B21 also had a high survival rate because of co‐dominant expression of these genes. In contrast, the homozygous B13 had a 100% mortality rate and they were the major mortality group. These results confirmed that MHC class I haplotypes influence avian influenza virus disease‐resistant traits in Thai indigenous chicken. The MHC genes can be used as genetic markers to improve disease‐resistant traits in chicken.     

禽流感病毒神经氨酸酶基因在重组杆状病毒中的表达

根据已知H5N1亚型禽流感病毒(AIV)神经氨酸酶(NA)基因序列设计并合成引物。从H5N1亚型病毒感染的鸡胚尿囊液中提取总RNA,反转录后采用高保真DNA聚合酶扩增NA基因,构建转移载体pFastBacHTA-NA,并与大肠杆菌DH10Bac的Bacmid质粒重组,构建重组转座质粒rBacmid-NA。在脂质体介导下将rBacmid-NA转染sf9昆虫细胞获得重组杆状病毒。在sf9昆虫细胞中表达NA蛋白,通过SDS-PAGE、Western blot和激光共聚焦检测蛋白。结果表明:表达的NA蛋白分子量约为53 ku,该蛋白能与H5N1亚型AIV血清发生特异性反应,证明NA蛋白表达正确,具有良好的免疫反应性。