不同方法及材料检测大片吸虫感染的比较试验

为片形吸虫病诊断提供高效、简便的新技术，以大片吸虫分泌排泄抗原（ES抗原），用于斑点酶联免疫吸附试验（Dot－ELISA）、琼脂扩散酶联免疫吸附试验（Dig－ELISA）、免疫胶体金滴渗法（DIGFA）检测动物体内的大片吸虫（Fasciolagigantica）感染。通过检测血清、血纸、牛奶等几种材料，多重试验比较，结果三种方法均具有敏感性高、特异性强、准确性可靠等优点，并各有特长，如操作简便快速、费用低廉，易于在基层推广应用等，同时证明用血纸和牛奶检测抗体效果同样可靠。本试验首次报道用Dot－ELISA、DIGFA在奶中检测片形吸虫抗体，为该寄生虫病普查提供一种新思路。     

间接ELISA和HI方法检测鸡新城疫病毒抗体的相关性分析

分别采用商品化的酶联免疫吸附试验（ELISA）抗体检测试剂盒和血凝抑制（HI）试验方法对152份临床血清样本和标准阴阳性血清进行新城疫病毒（NDV）抗体检测。比较间接ELISA和HI两种方法的相关性。研究结果表明，间接ELISA和HI两种方法呈显著相关，二者间的相关系数为0．9261：间接ELISA和HI两种方法检测NDV抗体的阳性符合率为96．8％，阴性符合率为92．9％，间接ELISA方法是一种敏感、特异、快速的血清学诊断方法，可以用于临床样本的大规模检测．     

检测禽流感病毒抗体的重组核蛋白间接ELISA方法的建立

以大肠杆菌系统表达的H9N2亚型禽流感病毒（AIV）核蛋白（NP）为抗原，建立了禽流感间接酶联免疫吸附试验抗体检测技术（NP—ELISA）。对263份待检血清（包括临床收集的243份血清和20份H9N2亚型AIV免疫鸡阳性血清）进行检测，NP—ELISA与琼脂免疫扩散试验（AGP）的总符合率为83．3％，与血凝抑制试验（HI）的总符合率为92％。特异性试验表明，NP—ELISA方法可以检测H5、H7和H9亚型AIV特异性抗体，检测为阳性的血清样品能够被阳性鸡胚尿囊液阻断。敏感性试验证实，NP—ELISA最早可以检测鸡感染后7d的血清样品，并于感染后10d确定100％血清阳性，而AGP检测直到首免后21～28d才出现部分血清阳性，HI检测直到10～14d才出现部分血清阳性，并且NP-ELISA要比HI敏感4～40倍。试验证明，NP—ELISA是检测AIV血清型特异性抗体的一种特异、敏感、快速、经济的血清学检测技术。     

DOT—ELISA检测猪瘟免疫抗体的研究

本文成功地建立了Dot—ELISA(斑点酶联免疫吸附试验)检测猪瘟免疫抗体,经猪丹毒、猪巴氏杆菌高免血清对照及猪瘟强毒攻毒试验证实;Dot—ELISA检测猪瘟免疫抗体是特异的。Dot—ELISA、ELISA和兔体中和三种方法比较,Dot—ELISA法具有简便、快速、敏感性高,特异性强。用Dot—ELISA法检测115头免疫猪血清抗体,免疫抗体在效价1:2—1:128之间,1:32—1:64以上滴度占95％。猪瘟攻毒试验结果:免疫猪的猪瘟免疫抗体保持在1:32以上,均能抗过猪瘟强毒的攻击。     

不同公司ELISA试剂盒与HI法检测鸡新城疫抗体的比较

分别采用A、B、C三个公司的商品化酶联免疫吸附试验(ELISA)抗体检测试剂盒和血凝抑制(HI)试验方法对168份临床免疫鸡血清和标准阴阳性血清进行新城疫抗体监测方法的比对试验与研究,比较间接ELISA和血凝抑制(HI)两种试验方法的相关性。研究结果表明,A、B、C三个公司生产的商品化间接ELISA抗体检测试剂盒的检测结果与血凝抑制(HI)试验的阳性符合率分别为98%、96.7%、90.2%;阴性符合率分别为86.7%、80%、86.7%;阴阳性总体符合率分别为97%、95.2%、89.9%;A、B、C三个公司的ELISA抗体检测试剂盒的检测时间分别为2.5、3、3h。产品价格分别为1100、800、700元。比较发现,间接ELISA方法是一种快速、敏感、特异的血清学诊断方法,不同公司生产的商品化ELISA抗体检测试剂盒在敏感性、特异性和检测时间上均存在较大的差异,综合分析,B公司生产的商品化酶联免疫吸附试验(ELISA)抗体检测试剂盒成本较低,敏感性较高,可以用于临床样本的大规模检测。     

基于p30-gp90融合蛋白的禽网状内皮组织增生症病毒抗体间接ELISA方法的建立

禽网状内皮组织增生症病毒（reticuloendotheliosis virus，REV）既可以诱发禽的肿瘤性疾病，又能引起感染禽群免疫抑制，给养禽业带来重大经济损失。REV抗体监测对于该病的诊断、预防和控制具有重要意义。本试验首先通过大肠杆菌表达系统表达了重组REV p30-gp90融合蛋白，随后建立了基于该融合蛋白的REV抗体间接酶联免疫吸附试验（ELISA），并对反应条件进行了优化。结果显示，p30-gp90间接ELISA的灵敏度（1:51 200）是间接免疫荧光法（IFA）（1:6 400）的8倍，与其他常见禽类病毒无交叉反应，且具有良好的批内和批间重复性。对从山东省部分地区养殖场采集的690份血清样品，同时利用p30-gp90间接ELISA和IFA进行检测，发现20.87%的血清样品经间接ELISA检测为阳性，间接ELISA和IFA的总体符合率为96.96%。结果表明，本研究建立的间接ELISA检测方法具有特异性强、敏感性高和重复性好的优势，为REV的快速诊断、流行病学调查和血清学监测提供了技术支持。     

免疫荧光间接染色法与酶联免疫吸附试验、补体结合试验对马鼻疽诊断的比较

马鼻疽的血清学诊断,过去一直采用补体结合试验(cF)。近几年来,我们又相继建立了微量间接血凝试验、乳胶凝集试验、免疫荧光间接染色法(IFA)及酶联免疫吸附试验(ELISA)等比较敏感的检测方法。为了比较IFA、ELISA、cF三种方法对鼻疽马检测的敏感性,我们对31匹鼻疽马及10匹经病理学确诊的鼻疽马进行了检测,现将结果报道如下。     

猪血凝性脑脊髓炎病毒抗体间接ELISA检测方法的建立及山东省猪血清抗体检测分析

首先应用血凝抑制试验(HI)对从山东省部分地区采集的178份猪血清样品进行了猪血凝性脑脊髓炎病毒(HEV)抗体检测。结果显示,这些猪群中HEV的HI抗体总体阳性率高达61.24%(109/178),说明HEV的感染较为普遍。同时,以纯化的病毒作为包被抗原,通过优化反应条件,成功建立了HEV抗体间接酶联免疫吸附试验(ELISA)检测方法。应用该ELISA方法对从山东地区猪血清中随机抽取的44份样品进行检测,结果显示,HEV抗体阳性率为72.73%(32/44);而HI抗体阳性率为56.82%(25/44)。两种检测方法的阳性符合率为92.00%。结果表明,建立的ELISA方法较HI方法敏感性高。     

ELISA检测IBV抗体方法的建立和标化

用蔗糖密度梯度离心和凝胶层析纯化传染性支气管炎病毒（IBV）作抗原，建立了检测IBV抗体的间接酶联免疫吸附试验（ELISA），特异性和重复性良好。已包放好抗原的ELISA板于—20℃保存5个月，不影响检验结果。     

间接ELISA和HI方法检测禽流感病毒抗体的相关性试验

分别采用商品化的酶联免疫吸附试验(ELISA)抗体检测试剂盒和血凝抑制(HI)试验方法对153份血清样本进行禽流感病毒(AIV)的H5抗体检测,比较间接ELISA和HI两种方法检测结果的相关性。研究结果表明,间接ELISA和HI两种方法呈较好的相关性,二者间的相关系数为0.765。间接ELISA和HI两种方法检测AIV抗体的阳性符合率为95.8%,阴性符合率为87.2%,总体符合率为96.7%。间接ELISA方法是一种敏感、特异和快速的血清学诊断方法,可以用于临床样本的大规模检测。     

Preliminary evaluation of diagnostic tests for avian influenza using the Markov Chain Monte Carlo (MCMC) Method in an emergency surveillance

In June 2005, an outbreak of avian influenza (AI) caused by a low pathogenic H5N2 virus was identified in Japan. A serological surveillance was conducted because the infected chickens did not show any clinical signs. The Markov Chain Monte Carlo Method was used to evaluate the performances of serological HI and AGP tests because there was not enough time when the surveillance was initiated to conduct a test evaluation. The sensitivity of the AGP test (0.67) was lower than that of the HI test (0.99), while the specificities were high for both tests (0.96 for AGP and 0.90 for HI). Based on the low sensitivity of the AGP test, the HI test was used for primary screening in later stages of the epidemic.     

Evaluation of a gel diffusion precipitin test for porcine parvovirus

The use of a gel diffusion precipitin (GDP) test for the detection of porcine parvovirus (PPV) infection in pigs is described. The close correlation between gel diffusion precipitin and haemagglutination inhibiting (HI) antibody titres indicates that, with careful standardisation, a high level of sensitivity can be achieved with the GDP test and that it is a simple and relatively inexpensive alternative to the more commonly used HI test. Experimental infection of 2 groups of pigs showed that GDP and HI antibody responses were closely correlated and that GDP antibodies to PPV persisted for at least 41 weeks after infection. In a commercial herd study, serological evidence of declining passive immunity and subsequent acquisition of active immunity was demonstrated by measuring the GDP and HI antibody titres in sequential serum samples of pigs from a known PPV endemic farm. The GDP test described was shown to be less sensitive than haemagglutination (HA) in the detection of viral antigen but was, nevertheless, considered useful as a simple screening test for the amounts of antigen usually present in PPV infected mummified foetuses.     

An adhesion-hemadsorption inhibition test for the detection of serum antibody to Mycoplasma gallisepticum

A simple adhesion-hemadsorption inhibition (AHAI) test was developed for the detection of antibodies to Mycoplasma gallisepticum in the chicken sera. The AHAI antibody was detected simultaneously with HI antibody from sera of chickens intratracheally inoculated with viable cells of M. gallisepticum. A good correlation between HI and AHAI antibody titers was obtained with 382 (84.7%) of 451 sera from chickens reared on farms spontaneously contaminated with M. gallisepticum, whereas the remainder, 69 sera, was positive for HI but negative for AHAI test. It was not apparent whether the latters exhibited a non-specific reaction or the discrepancy was due to the lower sensitivity of AHAI reaction. The AHAI test does not require a great amount of antigen, special reagents or instruments, or pre-absorption treatment of test sera, and, therefore, it may serve as a simple serological test for detecting antibodies to M. gallisepticum.     

The relationship between the hemagglutination-inhibition test and the enzyme-linked immunosorbent assay for the detection of antibody to Newcastle disease

An assay of 364 chicken serum samples for Newcastle disease virus antibodies determined that a commercial NDV enzyme-linked immunosorbent assay (ELISA) had a 98.2% sensitivity and a 91.7% specificity relative to the NDV HI test. The ELISA values regressed significantly (F = 930, df = 1/362, P less than 0.001) on the hemagglutination-inhibition (HI) titers. The correlational coefficient was 0.85. For individuals, two tests can have the same result based upon chance alone. Kappa is a measure of agreement between two tests that corrects for this chance agreement. The kappa between the ELISA and HI test was calculated to be 0.84 (Z = 7.74, P = 0.00001), which indicates a highly significant agreement between the two tests.     

3种犬细小病毒感染诊断方法比较

本研究应用犬细小病毒抗原快速检测试剂盒、血凝/血凝抑制试验和PCR方法对120份具有腹泻/呕吐症状的患犬粪便样本进行了犬细小病毒检测。结果显示,3种方法检测阳性份数分别为60,49,68。犬细小病毒抗原快速检测试剂盒与血凝/血凝抑制(HA/HI)试验相比较,敏感性、特异性及总符合率分别为100.0%,84.5%,90.8%;与PCR法相比较,敏感性、特异性及总符合率分别为85.3%,96.2%,90.0%。从试验结果看,HA/HI法具有较高的特异性,但敏感性较低;PCR具有高度敏感性和特异性,但不适合临床推广;细小病毒抗原快速检测试剂盒,在正确操作下结果可靠,是临床诊断犬细小病毒感染的首选方法。     

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.     

Preparation and diagnostic utility of a hemagglutination inhibition test antigen derived from the baculovirus-expressed hemagglutinin-neuraminidase protein gene of Newcastle disease virus

A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2¹³ per 25 µL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4℃. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays.     

Development and evaluation of indirect ELISA for the detection of antibodies against Japanese encephalitis virus in swine

The Japanese encephalitis virus (JEV) is one of causative agents of reproductive failure in pregnant sows. An indirect enzyme-linked immunosorbent assay (I-ELISA) was examined for its potential use in the rapid monitoring of the JEV, and the results were compared with those from the hemagglutination inhibition (HI) and serum neutralization (SN) tests. The comparative analysis showed that the results of I-ELISA showed a significant correlation with the conventional HI (r = 0.867) and SN tests (r = 0.804), respectively. When the I-ELISA results were compared with the traditional diagnostic assays, the sensitivity of the I-ELISA was 94.3% with the HI test and 93.7% with the SN test, respectively. The specificity was found to be 81.4% and 80.0% with the HI and SN tests, respectively. To determine the applicability of I-ELISA in the field, the serum samples from 720 pigs were collected from 4 regions in Korea between July and August 2004. The results indicated that 21.7% of screened pigs were seropositive for the JEV. The seropositive rates of JEV in the 4 provinces were 12.6% in Gyeonggi, 45.0% in Gyeongnam, 16.7% in Jeonbuk, and 12.2% in Jeju. The I-ELISA methodology developed in this study was shown to have considerable sensitivity and specificity through a comparison with HI and the SN tests. Therefore, it might be one of convenient methods for screening a large number of samples in various fields.     

Evaluation of the specificity and sensitivity of two commercial enzyme-linked immunosorbent assay kits, the serum plate agglutination test, and the hemagglutination-inhibition test for antibodies formed in response to Mycoplasma gallisepticum

Two commercial enzyme-linked immunosorbent assay (ELISA) kits, seven serum plate agglutination (SPA) antigens, and the hemagglutination-inhibition (HI) test for antibodies to Mycoplasma gallisepticum (MG) were compared for sensitivity and specificity using known MG-positive and MG-negative sera from leghorn chickens. All SPA antigens proved to be highly sensitive when testing MG-positive sera. Laboratory-prepared SPA antigens yielded fewer positive reactions when testing MG-negative sera than commercial SPA antigens. Both MG ELISA kits showed high rates of positive reactions when testing sera from birds given commercial M. synoviae bacterin, fowl coryza (Haemophilus paragallinarum) bacterin, inactivated infectious bursal disease virus vaccine, and to a lesser extent fowl cholera (Pasteurella multocida) bacterin. Immunization with Frey's medium with 12% swine serum-in-oil or Staphylococcus aureus-in-oil resulted in sera which yielded numerous positive ELISA reactions. During the first 1 to 3 weeks, antibodies induced by experimental infection with MG were better detected by the SPA test than by the ELISAs and the HI test, thus confirming the SPA test's importance in Mycoplasma diagnostic serology. The HI test can serve to confirm positive SPA results.     

Antibody responses of turkeys experimentally exposed to Mycoplasma synoviae.

The antibody response of turkeys exposed to Mycoplasma synoviae intravenously and by way of air sacs was determined by tube agglutination, plate agglutination, hemagglutination-inhibition (HI), and gel diffusion precipitin tests. The results suggested that continued antigenic stimulation was lacking in most turkeys and that the response was due mostly to IgM-type immunoglobulin. Under those conditions, both types of agglutination tests were effective and were more sensitive indicators of exposure than the HI test. The gel diffusion precipitin test was not considered effective under the conditions of this study. HI activity occurred in serums of intravenously exposed turkeys within 4 days of exposure. The sensitivity of this activity to 2-mercaptoethanol treatment suggested that IgM was responsible.