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1.
The sensitivity of an indirect enzyme-linked immunosorbent assay (ELISA) for bovine IgG serum antibody to Pasteurella haemolytica was compared with that of an indirect hemagglutination (IHA) test. Pasteurella haemolytica serotypes were grown in a chemically defined cell culture medium, and soluble antigens released into the growth medium were used in the ELISA and IHA test. An ELISA with serotype-1 antigen consistently detected antibody in sera that were positive by IHA test (correlation, 99%). Sera reacting with serotype-1 ELISA antigens also reacted with ELISA antigens prepared from other serotypes. Although ELISA titers averaged 5 log2 units higher than IHA titers, plots of titers determined by the 2 methods were approximately linear. Titer increases detected in paired serum samples by either test were similar. The ELISA was more sensitive than was the IHA in detecting colostral IgG antibody in serum of newborn calves. The ELISA uses a simple, stable antigen preparation and detects antibody to P haemolytica serotypes that commonly infect cattle.  相似文献   

2.
Groups of dogs reared free of both nematodes and cestodes were infected with Taenia hydatigena, Taenia pisiformis or Echinococcus granulosus. After infections with the Taenia spp became patent, dogs were purged to remove the worms. They were later reinfected and the second infections again removed by purging after patency. A group of 3 uninfected worm free dogs was kept as age-matched controls. The dogs were bled at intervals of 5 days and their serums tested for antibodies using the enzyme-linked immunosorbent assay (ELISA) with excretory/secretory (ES) antigens collected during in vitro incubation of evaginated scoleces (scolex ES antigen) and oncosphere antigens. Antibodies to scolex ES antigen were detected by 3 weeks after infection with each cestode species whereas antibodies to oncosphere antigen were not detected until about one week after eggs were found in the faeces of the infected dogs. Antibody responses to both oncosphere and scolex ES antigens decreased rapidly following removal of the worms by purging. Uninfected control dogs were invariably negative to both oncospheral and scolex ES antigens. There were cross-reactions between the serums from dogs infected with T. pisiformis and T. hydatigena when tested with scolex ES antigens, but oncospheral antigens showed a high degree of species specificity. Scolex ES antigens from E. granulosus were compared with those prepared from T. hydatigena and T. pisiformis for their ability to discriminate between antibodies in serums collected from dogs 31 and 32 days after infection with 100,000 protoscoleces of E. granulosus or dogs infected with Taenia spp.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
The biochemical and serological properties of 21 strains of Actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. For serologic typing, the indirect haemagglutination (IHA) and the double gel-diffusion tests were used. On the basis of their soluble surface antigens, our A. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. Serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. All strains contained two surface antigen components. In the strains belonging to serotype 1, one of the antigens was identical with the serotype-specific antigen of Pasteurella haemolytica T4. Both antigens of serotype 2 strains proved to be type-specific. Four strains received from Switzerland, including the holotype strain of A. pleuropneumoniae biotype 2, and three strains isolated from swine in the G.D.R. belonged to serotype 2. Both the double gel diffusion and the IHA tests detected a 2-way cross-reaction between biotype 1, serotype 2 and biotype 2, serotype 2 strains of A. pleuropneumoniae, which could be eliminated using cross-absorbed sera.  相似文献   

4.
A crude antigen extract of larval Taenia solium was shown by immunodiffusion (ID) and immunoelectrophoresis (IEP) to cross-react with rabbit antisera against pig serum proteins and larval T. hydatigena, and by enzyme-linked immunosorbent assay (ELISA) with antisera against pig serum proteins, Fasciolopsis buski, larval T. hydatigena, hydatid cyst, Hymenolepis diminuta and Dipylidium caninum. Immunoblotting demonstrated that the crude antigens extract contained epitopes of pig serum proteins of 48 and 66 kDa. The crude extract also contained a subunit of antigen B (95 kDa) which was also found in T. hydatigena and H. diminuta. Immunoperoxidase and indirect immunofluorescence studies showed that cross-reacting antigens were distributed mainly on the tegument of T. solium.  相似文献   

5.
Cyst fluid antigens of Echinococcus granulosus, Taenia hydatigena and T pisiformis were examined by electrophoresis using homologous and heterologous hyperimmune rabbit sera to these antigens. While arc 5 forming antibodies were identified in sera from rabbits immunised with E granulosus and T hydatigena cyst fluids, antibodies responsible for forming precipitating antigen B band were detected in rabbit antisera to E granulosus, T hydatigena and T pisiformis antigens. T hydatigena cyst fluid appears to contain antigen similar to E granulosus antigen 5 and probably antigen B while T pisiformis cyst fluid has mainly an antigen close to hydatid antigen B.  相似文献   

6.
The procedure of countercurrent immunoelectrophoresis in the diagnosis of Taenia hydatigena cysticercosis in goats was carried out for antemortem diagnosis of T. hydatigena cysticercosis in experimentally and naturally infected goats. The antigens of cyst fluid, scolex and membrane of T. hydatigena metacestodes were purified and compared. The sensitivity of the test in experimentally and naturally infected goats was 57.1 and 52.5%, respectively, whereas its specificity using antisera raised against T. solium cysticercosis, hydatid cyst and Fasciola gigantica was 66.7 and 83.4% with partially purified and fractionated antigens, respectively. Of all three antigens, the cyst fluid antigen was found to be most reactive. The test could be employed for antemortem diagnosis of T. hydatigena cysticercosis using purified antigen.  相似文献   

7.
Studies were conducted to evaluate antigens of Taenia solium (Tso) and Taenia crassiceps (Tcra) cysticerci in the ELISA test for the diagnosis of swine cysticercosis. The samples analyzed were cysticercosis positive and negative control sera and heterologous sera. Four antigens were assayed: vesicular fluid (VF) and crude (T) Tcra and scolex (S) and crude (T) Tso. All antigens showed good performance, but VF-Tcra was the best followed by T-Tcra. Sensitivity rates of ELISA were respectively, in 2nd and 3rd standard deviation cut-offs, 96.0 and 80.0% for the VF antigen and specificity of 97.5 and 100.0%. Cross-reactivity was verified only for hidatidosis and ascaridiosis. Due to the high performance observed, the ELISA test using Tcra antigens should be recommended for the diagnosis of swine cysticercosis.  相似文献   

8.
A sandwich-ELISA was developed for the detection of soluble Taenia hydatigena antigens in fecal samples of dogs. Affinity-purified polyclonal catching antibodies and alkaline phosphatase-conjugated detecting antibodies were employed, which had been obtained from rabbits hyperimmunized with excretory/secretory antigens derived from in vitro maintained adult Taenia hydatigena. The assay allowed the detection of 800 ng T. hydatigena antigen g-1 of feces as a lower limit. Six helminth-free dogs were each infected with 10 T. hydatigena cysticerci isolated from Swiss sheep. After prepatent periods ranging from 57 to 71 days, the dogs started to excrete Taenia eggs and/or proglottids. The ELISA detected Taenia antigens in all six dogs during the prepatent period starting individually between Day 18 and 45 post-infection (p.i.). Anthelmintic treatment of three dogs at Day 95 p.i. resulted in elimination of the cestodes and within the 5 following days in the disappearance of Taenia antigens from feces. The specificity of the assay was evaluated by testing crude antigens derived from helminths or bacteria. Four Taenia species showed cross-reactivity at concentrations of 5 micrograms protein ml-1. Conversely, no cross-reactions occurred with various antigen batches derived from Echinococcus granulosus, E. multilocularis, Dipylidium caninum, Mesocestoides corti, Diphyllobothrium sp., Toxocara canis and bacterial antigens (Salmonella and Escherichia). Moreover, fecal samples from dogs naturally infected with T. canis (n: 13), hookworms (n: 2), Trichuris vulpis (n: 13) and of 10 dogs with mixed infections with these three nematode groups were tested, and results confirmed the high degree of specificity. The Taenia antigens detectable by this ELISA remained immunologically stable in native feces stored at +25 degrees, +4 degrees or at -20 degrees C for at least 5 days.  相似文献   

9.
Steers sensitized or infected with Taenia saginata exhibited similar delayed-type dermal hypersensitivity (DTH) responses after intradermal inoculation with T. saginata or T. crassiceps skin test antigens. Steers sensitized to T. crassiceps cysticerci exhibited similar DTH responses to intradermal inoculation with T. crassiceps, T. saginata whole worm and T. saginata cysticerci antigens. No correlation existed between the DTH responses and the number of cysticerci in the carcasses. One sensitized/infected and one infected steer harbored cysticerci but exhibited no DTH responses. Infection with cysticerci did not elevate DTH responsiveness in sensitized animals.  相似文献   

10.
The sensitivity and specificity of the enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Taenia solium cysticercosis was evaluated in experimentally and naturally infected pigs, using T. solium larval scoleces and its fractionated 1st and 2nd peaks on Sephadex G-200 as antigens. First peak antigen gave maximum sensitivity and highest antibody titres. The overall sensitivity of this test was found to be 91.5, 95.8 and 70.8% with scolex, 1st and 2nd peak antigens, respectively. False positive reactions occurred in 9.09% of uninfected pigs with scolex and 1st peak antigens and cross-reactions occurred in 25% of Taenia hydatigena-infected animals using scolex and 2nd peak antigens. No cross-reaction was observed using 1st peak antigen. The specificity of the test was 92.3, 96.2 and 92.3% with scolex, 1st and 2nd peak antigens, respectively.  相似文献   

11.
The immunogenicity of DNA vaccines encoding three different Taenia ovis host-protective antigens was compared in mice and sheep. DNA vaccines encoding the 45W, 18k and 16k antigens of T. ovis were constructed. The ability of DNA vaccines encoding the 45W and 18k genes to express antigen was confirmed by Western blotting of transfected Cos-7 cells. BALB/c mice were vaccinated intramuscularly with 45W, 18k or 16k DNA vaccines and the humoral immune response analysed by ELISA. DNA vaccines expressing 45W, 18k or 16k antigen were immunogenic in mice and generated significant titres of antigen-specific antibody. Intramuscular vaccination of outbred sheep with the T. ovis DNA vaccines generated significantly lower titres of 45W-specific antibody and failed to generate 18k or 16k-specific antibody. The findings of this study show that each of the three T. ovis host-protective antigens are amenable to delivery via DNA vaccines, and that the parameters governing the efficacy of DNA vaccines in sheep require further investigation.  相似文献   

12.
作者报导用碘标记弓形虫病小鼠腹腔液分泌抗原对流免疫电泳新方法(RCIEP)直接检测受检猪特异性抗体。RCIEP与常规间接血凝(IHA)对50例病猪血清和50例健康猪血清进行对比试验,结果证实该法具有高度的敏感性、特异性和较好的重现性。在不同稀释度时,弓形虫病猪血清RCIEP和IHA的阳性率分别为94~100%(平均98.80%)和22~100%(平均58.80%),健康猪的假阳性率前者未出现,而后者有10%以上。从患病猪血清和抗原稀释度试验证实,RCIEP的敏感性较酶标对流(ELCEP)和常规CIEP分别高15倍和400倍。因此作者认为RCIEP可作为猪弓形虫病的一种特异诊断新方法。  相似文献   

13.
应用体外培养的泰氏锥虫制备可溶性抗原Ⅰ、抗原Ⅱ和代谢抗原.经测定,其蛋白含量每毫升分别为6.5mg、7.4mg和7.1mg.薄层等电聚焦电泳测定结果表明,抗原Ⅰ出现22条区带,抗原Ⅱ21条区带,代谢抗原28条区带,对照的伊氏锥虫琼脂免疫扩散抗原14条区带.经分析,泰氏锥虫抗原和伊氏锥虫抗原有4条区带在同一迁移率上.琼脂免疫扩散反应中,3种泰氏锥虫抗原均与相应免疫兔血清发生沉淀反应,抗原Ⅰ出现1条致密沉淀线,抗原Ⅱ和代谢抗原出现2~3条沉淀线,抗原效价为1:4~16.免疫电泳显示了类似的结果,抗原Ⅰ与免疫兔血清出现1条弧形沉淀线,抗原Ⅱ和代谢抗原与免疫兔血清出现了3条弧形沉淀线.间接血凝试验结果表明,泰氏锥虫自然感染牛血清效价为1:20~40,免疫兔血清为1:1280~5120.所制泰氏锥虫抗原对伊氏锥虫和媾疫锥虫血清也能很好地发生交叉反应,3份伊氏锥虫病马血清和3份伊氏锥虫人工感染兔血清血凝效价分别为1:10~40和1:8~1024;5份媾疫马血清有4份血凝效价为1:20~320.4份环形泰勒虫病牛血清均为阴性.  相似文献   

14.
An enzyme-linked immunosorbent assay (ELISA) with somatic (S) or excretory-secretory antigens (ES) was compared with an indirect haemagglutination assay (IHA) for ability to detect antibodies against Fasciola hepatica in sheep. The specificity of both assays was determined by testing sera collected from sheep experimentally or naturally mono-infected with Fasciola hepatica, Haemonchus contortus, Ostertagia circumcincta, Cooperia curticei, Taenia ovis, Eimeria spp., Trichostrongylus vitrinus, Trichostrongylus colubriformis or Nematodirus battus respectively. With S or ES antigens the specificity of the ELISA was 98% or 95% respectively, whereas the specificity of the IHA was 86%. Antibodies directed against Fasciola hepatica were detected by the ELISA with S or ES antigens from 2 weeks after infection until the end of the experiment, whereas the IHA detected antibodies from week 3. We conclude that the ELISA with S antigens compares favourably with the IHA and can be used for the serodiagnosis of ovine fasciolosis in the Netherlands.  相似文献   

15.
In order to monitor the progress of New Zealand's hydatids eradication campaign, a specific, serological, diagnostic test is required to identify infected sheep. An indirect haemagglutination test, using pyruvic aldehyde-stabilized sheep erythrocytes as the antigen carrier, was developed for the serodiagnosis of larval cestode infections of sheep. Using cyst fluid from Echinococcus granulosus, Taenia hydatigena and T. ovis as the antigens in this test, it was shown that the larval cestode species, responsible for an infection in sheep harbouring a single specific infection, could be identified by the higher titre given with the homologous antigen, in comparison to that given with the heterologous antigens. Sera of sheep infected with two or more species were also tested by this method, and the only specific infections to be diagnosed by differential titres were those due to the presence of live E. granulosus cysts. These antigens cannot be used for the diagnosis of specific larval cestode infections in the field because of the cross-reactivity between cyst fluids. However, the test did show that infection with larval cestodes could be diagnosed on a non-specific basis.  相似文献   

16.
Calves were vaccinated with antigens collected during in vitro cultivation of the larval stages of Taenia ovis, T. hydatigena or T. saginata, and challenged 4 weeks later with 4 000 T. saginata eggs. Calves vaccinated with T. saginata antigen were highly resistant to the challenge infection and those groups vaccinated with T. ovis and T. hydatigena were also significantly resistant.  相似文献   

17.
本试验对北京郊区5个规模化猪场断奶仔猪、育成猪、育肥猪和怀孕母猪采集血清共507份,同时采集密切接触饲养人员、仔猪、育肥猪的喉头拭子、母猪阴道拭子及公猪的精液共183份。分别使用间接血凝诊断试剂盒、法国ELISA试剂盒检测抗体;利用直接荧光染色法检测抗原,包括166份猪喉头拭子、阴道拭子和精液以及17份饲养人员喉头拭子。结果发现间接血凝诊断试剂盒、ELISA试剂盒抗体阳性率分别为4.14%和2.17%;抗原平均阳性率为14.8%,其中精液阳性率达到37.5%,母猪阴道拭子阳性率为27.5%,饲养人员阳性率为23.5%。本试验证实北京郊区猪嗜流产衣原体在种公猪、母猪群和饲养员呈高流行趋势。同时研究结果显示,5个被调查的规模化猪场嗜流产衣原体抗体阳性率显著低于有报道的其他省市,这与间接血凝诊断试剂盒检测结果高于ELISA试剂有关。针对发现的问题,必须采取有效措施控制种公猪精液污染衣原体现象,阻断向母猪和饲养人员传播,以降低人兽共患病发生的风险。  相似文献   

18.
An indirect hemagglutination (IHA) test using sonicated extract as the antigen was developed for the detection of antibodies to Clostridium chauvoei. This antigen can be adsorbed onto glutaraldehyde-fixed sheep red blood cells treated with tannic acid and can be destroyed by trypsin and heat treatment. It corresponded well with the flagella of the organism, when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the gel diffusion test. No serological cross-reactivity was found in the IHA test when the antigen was tested against 4 species of clostridial antibodies. Our results suggest that the IHA test mainly detects antibodies against the flagella of C. chauvoei.  相似文献   

19.
An antigenic fraction (ThFAS) isolated from Taenia hydatigena metacestode cyst fluid was used in an ELISA to detect antibodies to T saginata in experimentally and naturally infected cattle. In 10 calves given 1,000 to 100,000 T saginata eggs (20% to 60% viability), IgG and IgM antibodies were detected in all the calves by post-inoculation week 3. Immunoglobulin G antibody values remained increased until calves were slaughtered at post-inoculation weeks 13 to 26. Six naturally infected calves (determined by postmortem examination) were considered positive, using the ELISA. Shared antigens were demonstrated between ThFAS and T saginata and T crassiceps; there were no shared antigens between ThFAS and Haemonchus contortus or Fasciola hepatica. Specific lectin binding to ThFAS indicated the presence of glycoconjugates. Immunoblot analysis indicated that a low molecular weight polypeptide (10,000 Mr) bears the immunodiagnostic antigen.  相似文献   

20.
The primary and secondary immune responses were investigated in trout injected with haemocyanin (HCN) intramuscularly (IM) or intraperitoneally (IP), with or without adjuvant. HCN was detected in the blood 30 min after injection and clearance times varied after one injection from 8 to 56 days. Fish given two and three injections cleared the antigen faster. Precipitins against HCN were first detected 21 to 30 days after injection and were still present on Day 56. However, antibodies detectable by indirect haemagglutination (IHA) and complement fixation (CFA) were initially demonstrated 7 to 21 days after a single injection and highest titres were reached between 33 and 56 days according to the experimental protocol. In fish given two injections, maximum titres were reached between Days 42 and 56 (IM), and Days 50 and 56 (IP). With three injections, maximum CFA and IHA values occurred on Days 62 and 66 respectively in the case of IP, and on Days 103 and 106 respectively with IM. Overall, higher titres were found with IHA than by CFA.  相似文献   

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