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1.
The Eperythrozoon suis (E. suis) antigen was purified using a Sephadex G-200 chromatograph, and thereby, a high-affinity, specific E. suis antigen was collected and confirmed with Western blotting. Using this antigen, an enzyme-linked immunosorbent assay (ELISA) system to detect the antibody against E. suis in swine was established. There was no cross-reaction with swine sera, which were affected with Mycoplasmal pneumonia, swine fever, swine colibacillosis, or toxoplasmosis. A comparison of this ELISA system with an indirect hemagglutination (IHA) test using 78 swine samples revealed that the ELISA system significantly improved the sensitivity, specificity, and stability for the serodiagnosis of swine E. suis.  相似文献   

2.
A competitive enzyme-linked immunosorbent assay (ELISA) for the detection of swine trichinosis has been developed using a biotinylated monoclonal antibody and an avidin-enzyme conjugate. The assay is based on competitive binding between swine serum antibodies and a monoclonal antibody specific for an antigenic determinant present on proteins from Trichinella spiralis excretory-secretory products with molecular weights of 45,000, 49,000, and 53,000. The competitive ELISA reliably detected pigs infected experimentally with T. spiralis and eliminated false-positive reactions in pigs infected with other swine nematodes, particularly Trichurus suis. When the competitive ELISA and an indirect ELISA using affinity-isolated antigen were compared using serum from pigs with naturally-acquired infections of T. spiralis, both tests were highly effective in detecting infected animals.  相似文献   

3.
抗猪附红细胞体单克隆抗体的制备   总被引：1，自引：0，他引：1  
以纯化的猪附红细胞体免疫BALB/c小鼠,运用淋巴细胞杂交瘤技术进行细胞融合,并用间接ELISA方法进行筛选,经过间接ELISA方法、免疫印迹和间接免疫荧光试验进行鉴定,共获得5株分泌抗猪附红细胞体单克隆抗体的杂交瘤细胞,分别命名为1H1、1H2、3A5、5B1和7E11,其单抗亚类鉴定分别属于IgG2b、IgG1、IgG2b、IgG2b和IgG2b。这5株McAb均能与猪附红细胞体全菌蛋白发生特异性反应,而不与猪肺炎支原体、猪链球菌、大肠杆菌和猪繁殖与呼吸综合征病毒发生反应,并且1H1、3A5和5B1能识别同一抗原位点,1H2和7E11识别另一抗原位点。  相似文献   

4.
A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection and the identification of Streptococcus suis capsular types 1, 2, 1/2, 3 and 22. The specificity of this test was first evaluated using reference strains of S. suis capsular types 1 to 28 and 1/2 as well as 15 different bacterial species susceptible to be isolated from swine. The ELISA developed was very specific for capsular types 1, 3 and 22 but it could not discriminate between capsular types 2 and 1/2. In a second study, S. suis isolates from 328, 493, 368 and 76 diseased pigs were used to detect capsular types 1, 2 or 1/2, 3 and 22 respectively. The relative specificity and sensitivity varied between 98% and 100%. The ELISA results were in excellent agreement with the standard techniques (biochemical tests, coagglutination and capsular reaction tests) in detecting both positive and negative strains. Kappa values were 0.80, 0.99, 0.97 and 1.00 for detecting S. suis capsular types 1, 2 or 1/2, 3, and 22 respectively. To evaluate the relative-sensitivity of the test, primary cultures from 73 diseased pigs and tissue samples from 67 diseased pigs were used directly for detecting these capsular types. With primary cultures, the relative specificity and sensitivity (95.9% and 91.6% respectively) remained high and the test was very suitable (Kappa = 0.87). The ELISA using tissue samples gave a good specificity (97.6%), a moderate sensitivity (62.5%) and a low agreement with standard tests (Kappa = 0.64).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Serologic responses in 61 calves 3 to 34 days of age following immunization with bacterins containing a heat-killed rough mutant, Escherichia coli 0111:B4 (strain J5) were determined by an enzyme-linked immunosorbent assay specific for the IgG isotype. Administration of either heat-killed bacteria or oil-based adjuvants alone failed to enhance serologic recognition of common core antigens when comparing to nonvaccinate controls. Increased titers were uniquely and specifically limited to calves receiving the antigen in an oil emulsion. In a second experiment, age and initial, passively acquired titer recognizing the vaccinal antigen were not found to have any effect on the magnitude of the humoral response of 57 calves following immunization.  相似文献   

6.
Actinobacillus suis is a commensal opportunistic pathogen in swine. However, in recent years, an increasing prevalence of clinical signs associated with A. suis has been observed in high health status herds in North America. The objectives of the study were to assess the kinetics of antibodies to A. suis in pigs from a herd showing clinical signs of A. suis infection and, to evaluate the antibody response in gilts following vaccination with an autogenous vaccine. An enzyme-linked immunosorbent assay (ELISA) using a saline extract of boiled-formalinized whole cells of a field strain as the coating antigen was standardized. This ELISA was used as a tool for monitoring, in a comparative way, the variations in A. suis antibody levels. The herd selected for the serologic profile was negative for Actinobacillus pleuropneumoniae infection and showed clinical signs of A. suis infection in 16 to 19-week-old pigs. A cohort of 20 pigs was blood sampled at 5, 8, 12, and 16 weeks of age. The lowest level of serum antibodies was observed between weeks 8 and 12, this probably corresponding to a decrease in maternal immunity. A marked increase in the antibody response was seen at 16-week of age, at the approximate time of onset of A. suis clinical signs in the herd. The evaluation of serum antibody responses to an autogenous vaccine revealed that the humoral immunity of gilts further increased following vaccination although the level of antibodies was already high prior to vaccination. The magnitude of the response to vaccination was higher when the level of antibodies was low prior to the first injection. The ELISA test seems to detect antibodies against the O-chain LPS.  相似文献   

7.
An ELISA was developed and tested to detect antibodies to Eperythrozoon suis in swine. Results were compared with those of the indirect hemagglutination (IHA) test. Antigen isolated from swine heavily infected with E suis was used for both tests. Comparison of the ELISA with the IHA test revealed a significant (P less than 0.001) correlation between results. Of 114 samples obtained from 9 swine infected with E suis, 87.7% were seropositive (titer greater than or equal to 200) via the ELISA, and 80.7% were seropositive (titer greater than or equal to 20) via the IHA test. The sensitivity of the ELISA was greater than that of the IHA test. All blood samples obtained from specific-pathogen-free swine tested negative for E suis antibody. Cross-reactions were not observed between E suis antigen and antisera against various swine and cattle disease agents using ELISA. We concluded that the ELISA may be used for rapid and effective diagnosis of infection with E suis in swine.  相似文献   

8.
An enzyme-linked immunosorbent assay (ELISA) for the screening of brucellosis in reindeer was developed. The assay, which utilizes s-LPS from Brucella abortus as antigen and biotin-labelled rabbit antibody to reindeer immunoglobulin as detecting antibody, has a high specificity and sensitivity, as indicated in a validation with sera from reindeer cultured positive for Brucella suis biovar 4 and sera from reindeer free of brucellosis.  相似文献   

9.
Capsular polysaccharide antigens of serotypes 1, 2, 5 and 7 of Actinobacillus pleuropneumoniae were used in enzyme-linked immunosorbent assays (ELISAs) to test sera from experimentally infected and field pigs. Specific reactions were found in sera of experimental pigs with antigens of serotypes 1, 5 and 7 whereas the serotype 2 antigen was cross-reactive. A 1:200 serum dilution was used for testing of 300 sera from 21 swine herds in southern Ontario. Cases of pleuropneumonia had occurred in 11 of these herds, but not in the others. The negative cut-off value was the mean optical density at 405 nm (OD405) + three standard deviations (SD) for 16 negative reference sera. Sera from four pigs naturally infected with Actinobacillus suis were tested and found to react to varying degrees with each of the antigens. Therefore a second cut-off value was determined as the mean OD405 + 2 SD for the A. suis sera. Sera which, in the ELISA produced OD readings above the latter cut-off were considered positive for antibodies to A. pleuropneumoniae; those which were lower than the former cut-off were considered negative. Readings between the two cut-off values may have been due to low positive titers or cross-reactivity, possibly with A. suis, and could not be used to predict pleuropneumonia. Of the pleuropneumonia-free herds, none had positive reactors to serotypes 5 or 7, whereas one and two herds had positive reactors to serotypes 1 and 2, respectively. Of the pleuropneumonia positive herds, six had positive reactors to serotype 1, one to serotype 2, four to serotype 5, and eight to serotype 7.  相似文献   

10.
Enzyme-linked immunosorbent assays were conducted on milk of cows from which Brucella abortus was isolated and that of noninfected controls. Horseradish peroxidase-labeled rabbit antibovine immunoglobulins IgG, IgG1, and IgA were used as conjugates. A heat-killed whole-cell suspension of B abortus strain 19 was used as the antigen. Differences in antibody profiles were observed in milk of cows from which B abortus was isolated and in milk of noninfected cows. Antibody profiles were similar in milk of cows infected with B abortus and that of cows from which B abortus strain 19 was isolated.  相似文献   

11.
The recombinant ppa protein of Mycoplasma suis migrated to 21 kDa. Using this antigen, an ELISA system to detect the antibody against M. suis infection in swine was established. The rELISA demonstrated 98.5% specificities among negative samples and 96.9% sensitivity among positive samples with M. suis infection. A comparison of this ELISA system with an indirect hemagglutination assay (IHA) test using 132 swine samples revealed that the positive rate was 34.0% in ELISA and 28.0% in IHA. Compared with IHA, the present rELISA system using recombinant ppa antigen significantly improves the specificity, sensitivity, and stability for serodiagnosis of M. suis infection in swine.  相似文献   

12.
The evaluation of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against chlamydiae in pig sera is described. The most widely used serological test is the complement fixation test (CFT). The CFT has a lack of sensitivity and specificity because of low antibody titers and unspecific reactions. Eight conventionally raised pigs were exposed to a pathogenic strain of Chlamydia suis, four controls were mock infected. The immune responses was monitored by CFT and indirect ELISA. There was no agreement between CFT and ELISA data. These results were confirmed by a study with 191 sera from nine pig farms. As shown by ELISA and PCR chlamydiae are widespread in swine.  相似文献   

13.
Comparison of parasitological and serological diagnosis of trichinosis in swine was carried out on 36 pigs given 15,400 infective larvae each by gavage. Circulating eosinophil levels were determined and sera were examined by enzyme-linked immunosorbent assay for anti-Trichinella antibodies. Two pigs were killed per day from days 15 to 29 postinfection. Muscle was examined by pepsin-digestion and comparable tissue was fed to a rat. Eosinophil counts increased at about day 6 and reached peak levels about day 25 postinfection and returned to approximate preinfection levels about two months postinfection in those pigs still in the study. Infective larvae were recovered from all pigs killed at greater than or equal to 18 days postinfection. Using the criterion of 5 x mean optical density readings of negative sera as positive, seroconversion occurred between days 19 and 26 postinfection. Use of a lower criterion of 3 x mean optical density readings of negative sera resulted in only three of 30 pigs killed greater than or equal to 18 days postinfection seroconverting less than or equal to 18 days postinfection, when infective larvae were first recovered in the musculature. In pigs, even in those heavily infected, there is a lag between the period that trichinae in musculature become infective and development of antibodies as detected by enzyme-linked immunosorbent assay which results in false negative reactions in many animals. This study demonstrated that the enzyme-linked immunosorbent assay using an excretory-secretory antigen should not be used to certify pork or pork products free of infective Trichinella larvae or safe for human consumption.  相似文献   

14.
A saline extract of boiled-formalinized whole cells from a local strain (81–750; Quebec, Canada) of Actinobacillus pleuropneumoniae, serotype 5b was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of swine pleuropneumonia. Characterization of this crude extract was done and proteins, neutral sugars, hexosamines, and 2-keto-3-deoxyoctonate (KDO) were evaluated. On phenol extraction of the crude extract a serotype-specific antigen of polysaccharidic nature was recovered from the aqueous phase. This antigen was characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue, silver and Schiff stainings. Immunoblots were done using sera of experimentally infected pigs that showed serotype specificity and cross-reactivity. Overall, the results indicate that the O-chain of lipopolysaccharides is a specific antigen that could be used in ELISA for the serodiagnosis of serotype 5 of A. pleuropneumoniae.  相似文献   

15.
猪链球菌2型湖南分离株多重耐药性及相关耐药基因研究   总被引：1，自引：0，他引：1  
基因突变和基因转移是细菌耐药性产生和存在的重要内因,检测与抗生素耐药性相关的基因具有重要的意义.试验选取25份猪链球菌2型湖南分离株对16种抗生素进行药敏试验,检测菌株耐药性;选出了23株有红霉素抗性的菌株,用PCR检测其erm(B)基因.结果显示,猪链球菌湖南分离株对红霉素、四环素、万古霉素和克林霉素具有高耐药性,在23株红霉素抗性菌株中有18株存在erm(B)基因,由erm(B)基因产生的红霉素耐药菌株占到其中的78.3%.因此,erm(B)基因是链球菌2型湖南分离株对红霉素耐药的主要抗性决定基因.  相似文献   

16.
Counterimmunoelectrophoresis and enzyme-linked immunosorbent assay specific for rotavirus were performed on 253 calf gut and fecal specimens from eastern North Dakota. Rotavirus antigen was detected in 29 specimens by counterimmunoelectrophoresis and in 52 specimens by enzyme-linked immunosorbent assay. All of the counterimmunoelectrophoresis-positive specimens were positive by enzyme-linked immunosorbent assay. The counterimmunoelectrophoresis and the enzyme-linked immunosorbent assay, using a rabbit antirotavirus antibodies produced a golf ball-induced granuloma, were rapid and specific tests for the detection of rotavirus.  相似文献   

17.
A saline extract of boiled-formalinized whole cells from a local strain (81–750; Quebec, Canada) of Actinobacillus pleuropneumoniae, serotype 5b was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of swine pleuropneumonia. Characterization of this crude extract was done and proteins, neutral sugars, hexosamines, and 2-keto-3-deoxyoctonate (KDO) were evaluated. On phenol extraction of the crude extract a serotype-specific antigen of polysaccharidic nature was recovered from the aqueous phase. This antigen was characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue, silver and Schiff stainings. Immunoblots were done using sera of experimentally infected pigs that showed serotype specificity and cross-reactivity. Overall, the results indicate that the O-chain of lipopolysaccharides is a specific antigen that could be used in ELISA for the serodiagnosis of serotype 5 of A. pleuropneumoniae.  相似文献   

18.
Swine brucellosis is caused by the biovars 1, 2 and 3 of Brucella suis the identification of which up to now relies on microbiological tests lacking adequate specificity together with time consuming and expensive molecular procedures. Based on sequence variation of the omp2b gene, we have developed a four primer set multiplex PCR assay that was tested for polymorphism analysis of B. suis biovars causing brucellosis in swine. The assay exploits the single nucleotide polymorphisms found in omp2b gene of B. suis reference biovars which are conserved in 43 B. suis field isolates from different geographic origins and hosts. Three specific amplification patterns (S1, S2 and S3) were obtained for reference strains of B. suis biovars 1, 2 and 3, respectively. However, some B. suis field isolates identified as biovars 2 or 3 according AMOS-PCR, PCR-RFLP of omp31 and omp2 genes and classical bacteriological methods, resulted also in S1 patterns, limiting the typing usefulness of the method.  相似文献   

19.
Brucella suis biotype 1 was isolated from the semen of a dog with hindlimb weakness and a large, firm, left epididymis. A semen sample was oligospermic, with many neutrophils, the numbers of which decreased in serial sampling. A card agglutination test for B abortus and a rapid slide agglutination test for B canis were positive. The modified 2-mercaptoethanol slide agglutination test for B canis and the agar gel immunodiffusion test, using B canis cell wall antigen, were negative. At necropsy, chronic granulomatous inflammation was found in, and B suis biotype 1 was isolated from, the left epididymis and prostate gland.  相似文献   

20.
以原核表达纯化的猪(嗜血)支原体MSG1蛋白免疫BALB/c小鼠,运用细胞融合技术筛选分泌针对MSG1蛋白抗体的融合细胞。通过间接ELISA方法筛选获得2株能稳定分泌抗体的融合细胞株,分别命名为1A7和3G6,Western blot结果证明这2株细胞分泌的抗体能够与重组MSG1蛋白发生特异性反应。细胞上清和腹水中的ELISA抗体效价分别为1∶4 096、1∶1 024和1∶1 638 400、1∶51 200,其单抗亚类鉴定均属于IgG1,轻链为κ型。抗原识别位点分析结果表明,2株单抗所识别的抗原位点相同。猪(嗜血)支原体MSG1蛋白特异性单克隆抗体的制备成功,为制备免疫诊断试剂盒和致病机制的研究奠定了基础。  相似文献   

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