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 46 毫秒
1.
Enzyme immunoassays using the triple antibody enzyme linked immunosorbent assay (ELISA) with both Trichinella spiralis spiralis and T. spiralis nativa excretory-secretory (ES) antigens and a commercial Trichinella spiralis enzyme immunoassay test kit were carried out on sera from pigs that were infected with light, moderate and high doses of infective T. spiralis spiralis and T. spiralis nativa respectively. Seroconversion occurred in all pigs given infective Trichinella larvae although no trichinae were recovered from pigs given T. spiralis nativa larvae and examined between days 92 and 99 postinfection by pepsin digestion. Anti-Trichinella antibodies were detected in pigs infected with T. spiralis spiralis and T. spiralis nativa by ELISA using either the homologous or heterologous ES antigen. The commercial Trichinella spiralis enzyme immunoassay test kit also detected anti-Trichinella antibodies in both the T. spiralis spiralis and T. spiralis nativa infected pigs. The commercial test kit did not appear to be as sensitive as the triple antibody ELISA since it usually took two to three days longer for seroconversion to be detected by the former procedure. Finally seroconversion occurred more rapidly in swine infected with T. spiralis spiralis than with pigs receiving comparable doses of T. spiralis nativa.  相似文献   

2.
A field evaluation of an enzyme-linked immunosorbent assay (ELISA) for swine trichinosis was done with sera obtained from 5 herds experiencing ongoing transmission of Trichinella spiralis. Epizootiologic studies conducted on these herds offered an opportunity to evaluate the accuracy of an ELISA, using larval T spiralis excretory-secretory antigens. Sera from 162 infected pigs and 143 serum samples from noninfected pigs originating from the same farms were tested. The infection status of the pigs was determined by digestion of diaphragm or tongue muscle samples. Two criteria were established to classify the ELISA optical density (OD) readings: Criterion I stated that an OD greater than or equal to 5 times the mean OD of several normal swine sera pools was positive; criterion II stated that a OD greater than or equal to 4 times the normal sera values was positive. The results obtained did not reveal obvious serologic variations among infected herds located in the 4 states involved. Overall, the test detected 93% (criterion I) and 96% (criterion II) of infected pigs. The majority of false-negative sera was from hogs that had less than 5 larvae/g of muscle; 1 hog had 73.8 larvae/g of diaphragm muscle. The false-positive rates were 8% for criterion I and 9% for criterion II. The actual rate for these false-positive samples may have been overestimated, because generally, only small tissue samples (0.4 to 10 g) were digested; larger sample sizes might have altered the results. The relevance of this qualification is that these pigs originated from herds with prevalence rates greater than 50%. Other factors that may account for occasional false-positive sera or false-negative sera in the swine trichinosis ELISA are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
旋毛虫病McAb快速ELISA诊断盒的应用研究   总被引：3，自引：0，他引：3  
应用ＭｃＡｂ 快速ＥＬＩＳＡ 诊断盒,对感染了４ 个旋毛虫隔离种的猪定期检测其血清中抗体出现情况。结果,猪旋毛虫和旋毛形线虫（Ｔ．ｓｐｉｒａｌｉｓ）在感染２４ ｄ 后、犬旋毛虫和本地毛形线虫（ Ｔ．ｎａｔｉｖａ）３１ ｄ 后,可在猪血清中检出抗体;在抗体出现时间上前二者较后二者早７ ｄ 左右。  相似文献   

4.
旋毛虫病McAb快速ELISA诊断盒的研制与应用   总被引：7，自引：0，他引：7  
本研究建立了ＭｃＡｂ快速诊断猪旋毛虫病的ＥＬＩＳＡ试剂盒，应用旋毛虫单克隆抗体系和层析纯化抗原（ＰＡＡ）与旋毛虫肌幼虫排泄－分泌抗（ＥＳ）作常规ＥＬＩＳＡ平行检测６１头人工感染旋毛虫病猪血样，阳性率均为１００％，检测健康猪血样１０８２头，阴性率也为１００％，检测疫区自然感染猪血样１２５３头，阳性率分别为１．４４％和１．１２％，随机抽采１７５头猪血样和肉样作旋毛虫病消化法，常规法和快速法对比试验，诊  相似文献   

5.
The sequence encoding a truncated E2 glycoprotein of the Alfort/187 strain of classical swine fever virus (CSFV) was expressed in Escherichia coli using the pET expression system and the recombinant product purified by Ni-NTA agarose affinity chromatography. The antigenicity of this recombinant protein was demonstrated by immunoblot using anti- CSFV-specific antibodies. A monoclonal antibody was produced against the truncated E2 protein and used as competitor in an ELISA for the detection of antibodies to CSFV. Specific antibodies were demonstrated by competitive ELISA (C-ELISA) as early as 21 days post-infection (dpi) in experimentally infected pigs. Seroconversion was demonstrated by C-ELISA and neutralising peroxidase-linked assay (NPLA) in all infected animals by 4 weeks. No cross-reaction with antibodies to bovine viral diarrhoea virus (BVDV) was seen in the C-ELISA using sera from experimentally infected pigs. The C-ELISA is not intended as a substitute for the NPLA. However, it is expected it will be useful for monitoring and prevalence studies. It will also assist in testing a large number of samples in the event of an outbreak.  相似文献   

6.
A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Mycoplasma hyopneumoniae in porcine serum has been developed. The monoclonal antibody (mAb) reacts with an M. hyopneumoniae specific epitope on a molecule of approximately 74 kDa. Only sera from M. hyopneumoniae infected pigs were able to block the binding of the mAb although antibodies from M. flocculare infected pigs also recognized a 74 kDa molecule. Sera from experimentally infected pigs as well as field samples were compared by the ELISA and by an indirect hemagglutination assay (IHA). In experimental pigs, the earliest detectable antibody response was found to be almost identical for both assays, but for some of the pigs the time of detection was significantly earlier by blocking ELISA than by IHA. In naturally infected herds more samples were found to be positive by ELISA than by IHA. Furthermore, the results indicate that sera from naturally M. flocculare infected pigs may give rise to cross-reactions in the IHA. The blocking ELISA appears to be a valuable and reproducible tool in the surveillance and serodiagnosis of M. hyopneumoniae infections in pigs.  相似文献   

7.
An enzyme-linked immunosorbent assay (ELISA) using a detergent-solubilized antigen of purified virus was developed for detection of antibody against porcine transmissible gastroenteritis (TGE) virus in swine serum. The ELISA demonstrated antibody responses in pigs immunized intramuscularly with the attenuated TO-163 strain of TGE virus and in pigs orally infected with the virulent Shizuoka strain of the virus. The results of the ELISA were well correlated with those of the neutralization test. These results indicate the usefulness of the ELISA as a serological tool for TGE virus antibody.  相似文献   

8.
为评价单克隆抗体用于检测旋毛虫循环抗原（ＣＡ）的应用价值，作者利用淋巴细胞杂交瘤技术制备了４个抗旋毛虫ＣＡ的杂交瘤细胞系，建立了以单克隆抗体双抗体夹心ＥＬＩＳＡ检测ＣＡ的方法，并初步应用于动物血清中ＣＡ的检测。应用该法检测旋毛虫病猪血清的阳性率为７２．１％（３１／４３）。６０头健康猪、３０头感染猪囊虫和３０头感染弓形虫的猪均为阴性。对流行地区河南邓县３４头和湖北囊樊１３４头屠宰猪进行流行病学调查，  相似文献   

9.
Groups of hog sera from endemic and non-endemic areas for swine trichinellosis in Yugoslavia were tested by ELISA using excretory-secretory (ES) antigens collected from T. spiralis muscle larvae maintained in vitro for 24, 48 or 72 h. The 24-h ES had the highest level of specificity for T. spiralis infection. Antigen preparations recovered after 48 or 72 h yielded an increasing rate of false-positive reactions. Additional antigens occurred in the 48- and 72-h ES preparations as determined by gel electrophoresis and monoclonal antibody binding. The occurrence of false-negative reactions was directly correlated with T. spiralis worm burdens. Hogs with muscle larvae densities greater than 10 larvae per gram were all positive by ELISA. Among 17 hogs with less than 10 larvae per gram, only one hog was negative by ELISA with 24-h ES antigen; the false-negative rate was higher with 48- and 72-h ES. These results show that ES antigen produced during the first 24 h of in vitro cultivation is highly specific for the immunodiagnosis of swine trichinellosis.  相似文献   

10.
用消化法所得的猪旋毛虫、犬旋毛虫、旋毛形线虫 (Trichinellaspiralis)和本地毛形线虫 (Trichinellanativa)分别感染健康猪。结果表明 :4个旋毛虫隔离种对猪的感染性存在着明显差异 ,猪旋毛虫和T .spiralis对猪易感 ,其繁殖力指数 (RCI)分别为 385 .6 8± 41.5 1和 30 0 .5 5± 12 .45 ;而犬旋毛虫和T .nativa对猪不易感 ,RCI分别是 0 .0 6 4± 0 .0 31和 0 .0 33± 0 .0 33。结果揭示黑龙江省猪旋毛虫相当于T .spiralis,犬旋毛虫相当于T .nativa ;犬旋毛虫和T .nativa很难通过猪的感染而对人体健康构成威胁。  相似文献   

11.
A fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low diagnostic value (area under ROC curve=0.48) with the sera from the Zambian pigs while a relatively high diagnostic value was obtained with the sera from Cameroonian pigs (area under ROC curve=0.78). The main factor contributing to a low diagnostic value based on the Zambian serum samples seemed to be the false-positive reactions that were likely caused by the occurrence of transient antibodies in the non-infected animals.  相似文献   

12.
  相似文献   

13.
Serum samples obtained from 40,927 swine at various locations in North Carolina between Aug 1, 1987 and July 31, 1988, were tested for antibodies to Trichinella spiralis, using an ELISA based on a larval T spiralis excretory-secretory antigen. In the ELISA, samples were considered to have positive results if the optical density (OD) reading was equal to or 5 times greater than the mean OD value of 4 negative-control sera from trichina-free swine. Of the 40,927 serum samples tested, 154 (0.38%) were positive by ELISA; the rate for breeding swine was 0.35% (105/30,162), and the rate for cull swine was 0.45% (49/10,765). Of the 49 seropositive samples from cull swine, 11 were from out of the state, 22 had no identification, and 16 were known to originate from North Carolina. Seropositivity had a bimodally seasonal distribution, with peaks in March and September. There was no difference between the mean age of seropositive and seronegative swine, but males were at greater risk for seropositivity than were females. Pigs from lots with less than 100 sera tested were at increased risk for seropositivity, as were pigs from the central coastal region of North Carolina.  相似文献   

14.
We established a sandwich enzyme-linked immunosorbent assay (ELISA) for swine interleukin-6 (SwIL-6), which was applied for detection of SwIL-6 in vitro and in vivo. Anti-SwIL-6 rabbit- and goat-polyclonal antibodies, and monoclonal antibody (mAb) were prepared, conforming that all of the antibodies were reactive with recombinant SwIL-6 by Western blotting and indirect ELISA. A sandwich ELISA was developed using the mAb as a capture antibody and biotinylated goat-polyclonal antibody as a detection antibody. The detection limit of the sandwich ELISA for rSwIL-6 was 49pg/ml and did not show cross-reactivity with swine IL-1b, IL-4, IL-8, IL-18, IL-12, and IFN-g. Using the ELISA, SwIL-6 was detected in culture medium of the monocytes stimulated with PHA-P and PMA, and the plasma or the bronchoalveolar lavage fluid (BALF) of pigs experimentally infected with Actinobacillus pleuropneumoniae or Mycoplasma hyopneumoniae. This ELISA for SwIL-6 may be useful for understanding the role of this cytokine in various swine diseases.  相似文献   

15.
A polymerase chain reaction (PCR) assay was combined with a broth-culture enrichment system to detect Salmonella shed in feces from subclinically infected swine. The effectiveness of the broth culture-polymerase chain reaction (BC-PCR) assay to identify pigs shedding Salmonella in feces was compared with a microbiological culture and a commercial enzyme linked immunosorbent assay (ELISA) kit to detect Salmonella-specific serum antibody. A total of 67 pigs were tested by each of the 3 methodologies. Forty-one pigs tested positive for Salmonella by BC-PCR and ELISA identified 6 positives and 23 suspicious samples. It was shown that the BC-PCR assay is a rapid diagnostic tool for detecting of Salmonella shed by asymptomatic swine compared with current diagnostic technologies.  相似文献   

16.
The latex agglutination (LA) test, using muscle-juice samples of pigs experimentally infected with Trichinella spiralis and slaughtered 95 days post-infection (p.i.), gave visible results in 3 min; even in a pig receiving an infection dose as low as 10 larvae. The test appeared reliable and easy to perform without the need for special equipment or sample treatments which are necessary for ante-mortem diagnostic methods. The muscle-juice sample could be obtained by compressing the muscle pieces with the fingers at any time post-mortem and was used undiluted. The results of the LA test using serum or muscle-juice samples correlated with those of the enzyme-linked immunosorbent assay (ELISA). Positive results in the LA test and ELISA appeared 27 days p.i. with the use of sera from the pigs infected with greater than or equal to 600 larvae and 56 days p.i. with the serum of a pig infected with 10 larvae. The complement-fixing antibodies were detected in the sera using complement ELISA 86 days p.i. This assay was negative when muscle-juice samples were used.  相似文献   

17.
A competitive enzyme-linked immunosorbent assay (C-ELISA), based on a truncated E2 recombinant protein of the Alfort/187 strain of classical swine fever virus (CSFV) and a specific monoclonal antibody M1669, was evaluated using 2,000 sera from clinically healthy pigs in Canada (a CSFV-free country) and sera from experimentally infected pigs. The relative specificity and sensitivity of the C-ELISA were 100% and 86%, respectively, at a cutoff of 25% inhibition using negative and positive pig sera, as defined by the neutralizing peroxidase-linked assay (NPLA). A kappa value of 0.91 was obtained, indicating an excellent level of agreement between the NPLA and the C-ELISA. When sera from 120 infected pigs were used in the test at > or = 21 days postinfection, the sensitivity of the C-ELISA and the kappa value increased to 97% and 0.98, respectively. This C-ELISA will be useful when a large number of samples must be tested, as could occur during a disease outbreak or for surveillance or prevalence studies.  相似文献   

18.
To facilitate the control of progressive atrophic rhinitis (PAR) of swine caused by toxigenic Pasteurella multocida, an enzyme-linked immunosorbent assay (ELISA) and a serum neutralization test (NT) have recently been developed to detect antibodies against the P. multocida dermonecrotic toxin (PmDNT). However, the NT is a cumbersome and time-consuming technique. To overcome these drawbacks, we developed an indirect ELISA, using recombinant PmDNT expressed in Escherichia coli, for the detection of antibodies to PmDNT in serum samples from pigs. The practical usefulness of this ELISA was compared with the NT using serum samples obtained from experimentally infected and naturally infected pigs. In the pigs experimentally inoculated with vaccine including PmDNT toxoid, the ELISA and neutralization antibodies were detected at almost the same time, and a good correlation was demonstrated between both tests (P<0.01, R(2)=0.807). Therefore, the ELISA can be used to evaluate the immune reaction of pigs after vaccination with P. multocida toxoid. In a survey conducted on a field herd with a history of clinical AR, the seropositivity by ELISA in pigs of age 4.5-6 months was increased even though the NT was negative, and the correlation was low between the results obtained with the two tests (P<0.01, R(2)=0.38). Therefore, the results indicated that this ELISA might be a useful alternative to the NT currently used to detect the antibody to PmDNT after vaccination or infection with P. multocida.  相似文献   

19.
A commercially available blocking ELISA was analyzed for its ability to identify antibodies to porcine coronaviruses (transmissible gastroenteritis virus [TGEV] or porcine respiratory coronavirus [PRCV]), to differentiate antibodies to TGEV and PRCV, and to identify TGEV-infected herds. Nine sera from uninfected pigs, 34 sera from 16 pigs experimentally infected with TGEV, and sera from 10 pigs experimentally infected with PRCV were evaluated using both the TGEV/PRCV blocking ELISA and a virus neutralization (VN) assay. The ELISA was not consistently effective in identifying pigs experimentally infected with TGEV until 21 days postinfection. Sera from 100 commercial swine herds (1,783 sera; median 15 per herd) were similarly evaluated using both tests. Thirty of these commercial herds had a clinical history of TGEV infection and a positive TGEV fluorescent antibody test recorded at necropsy within the last 35 months, while 70 herds had no history of clinical TGEV infection. The blocking ELISA and the VN showed good agreement (kappa 0.84) for the detection of porcine coronavirus antibody (TGEV or PRCV). The sensitivity (0.933) of the ELISA to identify TGEV-infected herds was good when considered on a herd basis. The ELISA was also highly specific (0.943) for the detection of TGEV-infected herds when the test results were evaluated on a herd basis. When sera from specific age groups were compared, the ELISA identified a greater proportion (0.83) of pigs in herds with TGEV antibody when suckling piglets were used. In repeatability experiments, the ELISA gave consistent results when the same sera were evaluated on different days (kappa 0.889) and when sera were evaluated before and after heating (kappa 0.888). The blocking ELISA was determined to be useful for herd monitoring programs and could be used alone without parallel use of the VN assay for the assessment of large swine populations for the detection of TGEV-infected herds.  相似文献   

20.
An enzyme-linked immunosorbent assay (ELISA) using excretory-secretory antigens was developed to study the dynamics of the IgG antibody response to varying levels of Trichinella spiralis infection in the guinea pig. Four groups of four Hartley guinea pigs each were infected with 1250, 250, 50 or 10 T. spiralis infective muscle larvae. They were bled every 15 days for 6 months and the IgG antibody response determined by ELISA. The time of seroconversion was dose dependent as the larger the dose, the earlier the response occurred. Significant differences in antibody response between the dose groups were evident at 30 days post-infection (P less than 0.05). Beyond 60 days post-infection, the response was similar in the four groups. The antibody response in the groups infected with 250 and 50 infective larvae was similar, but was significantly different from that of the high (1250) and low (10) dose groups from 30 days post-infection (P less than 0.01). Once seroconversion occurred, the antibody titer rose to the same level, irrespective of the initial dose. To compare the antibody response according to muscle larvae recovered, the guinea pigs were grouped into four categories: less than 10 larvae; 10-25 larvae, 50-80 larvae, greater than 100 larvae. A significant positive correlation (P less than 0.05) was observed at 60 days post-infection when these groups were compared.  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