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1.
Antibody responses of sheep vaccinated with foot rot vaccines   总被引：1，自引：0，他引：1  
Enzyme-linked immunosorbent assay (ELISA) and crossed immunoelectrophoresis (IEP) were used to investigate antibody responses of sheep vaccinated with a double adjuvanted or single adjuvanted commercial foot rot vaccine. ELISA detected an antibody response of greater magnitude to the double adjuvant vaccine compared with the single adjuvant vaccine. Sera from sheep vaccinated with double adjuvant vaccine recognised at least six antigens of Bacteroides nodosus in crossed IEP while sera from the single adjuvant vaccinated sheep recognised one antigen. The use of non-denatured antigens of B nodosus in ELISA and crossed IEP enabled quantitative comparisons of antibody responses to the different foot rot vaccines to be made.  相似文献   

2.
Two African swine fever virus (ASFV) antigens were tested for use in an ELISA to detect antibody to ASFV. Antigens used were the cytoplasmic soluble fraction (CS-P) of infected cells grown in the presence of porcine serum and the semipurified viral structural protein VP73 (SVP73). Both antigens were tested by ELISA against 72 sera obtained during several ASF field episodes and from ASFV-inapparent carriers. Of the 72 sera, only 2.8% has positive results by ELISA against CS-P antigen; 60% of positive-reacting sera (to both antigens) had higher ELISA values when the CS-P antigen was used. Samples (with positive results) that reacted only to CS-P antigen had results confirmed by immunoblot analysis. Such sera reacted against ASFV-infection proteins IP25, IP25.5, and IP30, but not against IP73. In time-course experiments to detect appearance of ASFV-antibodies in infected miniature pigs, antibodies were detected by immunoblot analysis on postinoculation day (PID) 8. At that time, only the polypeptides IP25, IP25.5 IP30, and IP31 were recognized; IP73 and IP12 were first detected 3 and 4 days later, respectively. In the same experiments, ASFV antibodies were detected by ELISA, using CS-P or SVP73 antigens, on PID 7 and 9, respectively. These results could explain the percentage of sera not having positive results by ELISA using SVP73 antigen, if the sera were obtained from ASFV-infected pigs during the first days of infection before induction of antibody response against the IP73 protein. This feature makes the use of CS-P antigen advantageous in early serologic detection of ASFV-infected pigs.  相似文献   

3.
Soluble antigens from culture-grown Besnoitia besnoiti endozoites were identified following their partial purification by affinity chromatography. A specific eluate obtained after affinity chromatography on a column to which antibodies from serum of a naturally infected cow were bound exhibited seven polypeptide bands on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Five bands were observed in the eluate from an immunoadsorbent to which antibodies from an experimentally infected calf were coupled. Eluted antigens were reactive in the enzyme-linked immunosorbent assay (ELISA). Reactivity of electrophoretically resolved antigens with sera of endozoite-inoculated cattle and sera from field cases of besnoitiosis were studied using the Western immunoblotting technique.  相似文献   

4.
Serum Ig from Trypanosoma congolense-infected cattle were affinity-purified using immobilised trypanosome or non-trypanosome antigens (beta-galactosidase, cytochrome C and ferritin). The bound and unbound IgG and IgM fractions were collected and tested in ELISA for reactivity to each antigen. The results indicated that the presence of reactivity to non-parasite antigens in serum of infected cattle is due to polyreactive IgM antibodies. However, the IgG fraction only bound to trypanosome antigens and was only present in post-infection sera, indicating that it was induced by the infecting trypanosomes. Since the polyreactive IgM antibodies were also present in pre-infection sera, it is probable that they were natural antibodies that were not induced but only amplified by the trypanosome infection.  相似文献   

5.
Two enzyme-linked immunosorbent assays (ELISA), one based on a mouse anti-Trypanosoma brucei group-specific monoclonal antibody and the other on rabbit anti-Trypanosoma evansi polyclonal antibodies, have been evaluated for their ability to detect circulating trypanosome antigens in camel sera as a means for the diagnosis of T. evansi infections. All 91 sera from a negative control camel herd from Kenya gave negative antigen-ELISA results in the monoclonal antibody-based ELISA and only 2 of them (2.2%) gave false positive results in the polyclonal antibody-based ELISA. In subsequent analyses of sera from infected camels (as determined by mouse inoculation), the monoclonal antibody-based ELISA detected antigens in 90 (83.3%) out of the 108 sera tested. This percentage was lower for the polyclonal antibody-based ELISA which was able to detect antigens in 67 (60.9%) out of the 110 sera tested. The two tests detected probably different antigens and when the results were combined, 99 out of 107 (92.5%) sera were shown to be ELISA positive. In a survey involving 316 camels from the Gao and Nara areas, in Mali, a high proportion of animals tested were antigen positive (43.5 and 42.9%, respectively for the mono- and polyclonal antibody-based ELISA) compared to only 22 (7.0%) diagnosed by the parasite detection techniques. Thus, these immunoassays were at least six times more sensitive than the haematocrit centrifugation technique. As a large proportion of cases may be antigen positive but parasite negative, these two of "surra" immunoassays should be used in routine diagnosis in addition to the parasite detection techniques in the dromedary camel.  相似文献   

6.
Single fecal and serum samples were individually collected from 101 bovines selected at random during a visit to a farm in northeastern Spain (Group I, 26 animals aged 2-36 days; Group II, 34 animals aged 1.5-4.5 months; Group III, 41 animals aged 20-24 months). Testing for the presence of Cryptosporidium parvum oocysts in feces (Monofluo Kit Cryptosporidium, Diagnostics Pasteur, France) indicated that 26% animals were infected (81% of Group I, 15% of Group II and 0% of Group III). Serological testing (ELISA for detection of specific anti-C. parvum IgG) indicated that 59% animals were seropositive (12% of Group I, 74% of Group II and 78% of Group III). Immunoblotting results indicate that cattle sera recognize C. parvum antigens of widely varying molecular weights and that the number of antigens recognized increases with age. Immunoblots revealed that some of the sera belonging to the Group I reacted with protein fractions between 15 and 20 kDa but none recognized the 21-23 kDa antigen. Only few sera in the Group II recognized the protein fraction between 15 and 20 kDa. The recognition of 21-23 kDa fraction was observed by four sera from uninfected and seropositive animals. Sera from all the seronegative Group II animals recognized few antigens and always with molecular weight greater than 50 kDa. Serum samples from both seropositive and seronegative animals belonging to the Group III recognized antigens with molecular weight ranging 15-20 kDa. Surprisingly, the protein fractions between 21 and 28 kDa reacted with approximately 30% of the sera from seropositive animals and only one of the nine sera from seronegative animals. The recognition of 42-46 kDa antigens increased with the age and only reacted with the sera from uninfected animals.  相似文献   

7.
In this investigation the Western blot test was treated as a method verifying results of the IFA, commercial ELISA and standardized ELISA tests (described in Part I). The verifying investigations were performed on 82 serum samples, which in the commercial ELISA were positive in 36 cases, dubious in 31 cases and negative in 15 cases as well as on 5 serum samples obtained from horses infected with Leptospira spp., which in the ELISA commercial were dubious (total of 87 sera samples). The antigens, against which the immunological response in horses was directed, were also established. The Milenia--Blot--Borrelia IgG test (MIDBO IgG-Kit 30 Tests: DPC Bierman GmbH) was used in the investigation. In view of species differences, rabbit anti-horse IgG (whole molecule) alkaline phosphatase conjugate, no A6063 SIGMA-ALDRICH was used interchangeably. Also the control sera were substituted with the horse control sera. It was demonstrated that the Western blot test is the most reliable in the serological diagnosis of B. burgdorferi infection in horses. The commercial ELISA and standardized ELISA tests represent a lower diagnostic value than the Western blot test, although similar to each other, while the value of the IFA is minimal. In the Western blot test antigens were established against which the immunological response in horses in mostly directed. In the sera evaluated in this test as positive the presence of antibodies, mainly against antigens with the following molecular weights: 41 kDa, 62/60 kDa, 93 kDa, 72 kDa, 34 kDa (OspB), 66 kDa was noted. At the same time, antibodies contained in the sera accepted as negative, in 55.5% cases also reacted with the antigen of 41 kDa. It points to its minimal specificity. On the basis of the results obtained it is recommended that serological examination of horses should be with the ELISA and that positive or dubious results should be verified with the Western blot test.  相似文献   

8.
An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies in bovine sera against Parafilaria bovicola nematodes was developed and its sensitivity was compared with the immunodiffusion (ID) method. An exoantigen of P. bovicola which was shown to contain four major polypeptides was used in these procedures. The serological reactivity of the antigen polypeptides was defined by using the enzyme-linked immunoelectrotransfer blot technique (EITB) and whole-worm extract proteins. It identified only four serologically reactive polypeptides with sera from one experimentally infected calf and a verified field case. These two positive sera reacted mainly with four major antigens which coincided in molecular weights of the polypeptides of the exoantigenic preparation, namely, 43, 39, 28 and 25 KDa. Calves experimentally infected with P. bovicola showed a positive reaction with ELISA at 4 months after inoculation, and after this period a rapid increase in serum antibody response occurred. In these cases the ID reaction was observed for the first time at 7 months after inoculation. The specificity of an ELISA method using crude exoantigen preparation of P. bovicola was tested for the diagnosis of bovine parafilariasis. No cross-reactivity was detected when the P. bovicola exoantigen preparation was tested against sera from calves experimentally infected with Onchocerca lienalis, as well as against the sera from cattle naturally infected with Dictyocaulus viviparus or from cattle chronically infected with Ostertagia ostertagi. In addition, testing of 740 field sera from cattle in areas non-endemic and endemic for P. bovicola indicated a specificity of the antigen preparation used. Forty sera from laboratory-confirmed field cases of P. bovicola infection were tested by ELISA and immunodiffusion. All of these sera were ELISA positive, whereas only 70% of these were positive in the ID test. Seven (2.1%) of 328 sera from 21 herds from non-endemic P. bovicola areas were ELISA positive, as opposed to none in the ID test. Of the 94 sera from six herds in areas endemic for P. bovicola infection, 51 (54%) were ELISA positive whereas only 24 (26%) were positive in the ID test. When 56 slaughtered cattle, with varying degrees of meat condemnations due to parafilariasis, were tested for P. bovicola specific antibody, 91% of the serum samples were positive by ELISA. These results suggest that the exoantigen of P. bovicola can be used in a sensitive and reliable serological detection of parafilariasis by ELISA.  相似文献   

9.
Enzyme-linked immunosorbent assay (ELISA) was used for detecting the antibodies in sera from swine experimentally infected with Mycobacterium avium. Positive ELISA reactions were observed in the sera of each of six swine at postinoculation weeks 2, 4, 6, 8, and 10; no reaction was observed in noninoculated controls. The ELISA reactions were observed in each of two swine at 4, 6, 8, 10 weeks following exposure to M avium-infected swine. Mycobacterium avium-purified protein derivative and killed cells of M avium serotype 4/8 and serotype 8 provided suitable ELISA reactions in M avium-infected swine.  相似文献   

10.
An enzyme linked immunosorbent assay (ELISA) was used to determine antibody levels in cattle infected with Theileria parva and T annulata, using antigens prepared from the intra-erythrocytic piroplasm stage of the parasites. Antibody levels in calves infected with T parva increased from the 16th day after infection to reach peak values at days 28 to 35 and then declined rapidly, but in calves infected with T annulata antibody levels rose steadily up to day 40. Similar patterns of antibody production were shown by indirect fluorescent antibody tests. Sera from animals infected with T parva gave higher ELISA values with the antigen prepared from the homologous parasite species than with the antigen prepared from T annulata, but sera from cattle infected with T annulata gave similar high ELISA values with antigens prepared from both T parva and T annulata. Sera from animals infected with T mutans, T sergenti, T velifera, Babesia divergens, B major and B bovis gave only slight or no cross reactions with the piroplasm antigens, but serum from a calf infected with B bigemina cross reacted at a significant level with both piroplasm antigens.  相似文献   

11.
Enzyme-linked immunosorbent assay (ELISA) was compared with electron microscopy in the examination of faeces from experimental calves and showed 100 per cent agreement in the detection of 19 bovine coronavirus and 15 bovine rotavirus electron microscope positive samples. In a limited field survey of calf diarrhoea 75 selected faeces were examined independently by ELISA and electron microscopy and the agreement between the two tests was 95 per cent for coronavirus and 84 per cent for rotavirus. A further comparison was made with 74 samples submitted for routine diagnosis and this yielded agreements of 82 per cent (coronavirus) and 89 per cent (rotavirus). Factors contributing to discrepant results were examined and the relative advantages and disadvantages of the two tests for routine detection of these enteric viruses are discussed.  相似文献   

12.
Echinococcus granulosus worm excretory/secretory antigens (WES) were used in ELISA for diagnosis of E. granulosus infection in dogs and compared with protoscolex somatic antigens (PSM). Sera from 224 dogs were tested. There was no correlation between ELISA absorbance values and E. granulosus worm burdens using either antigen. There was a significant linear relationship between absorbance values of sera tested in the ELISA using WES (W-ELISA) and the ELISA using PSM (P-ELISA). However, there was a small but significant difference between the absorbance values of the sera tested against the two antigens. Western blot analysis of WES using sera from E. granulosus-infected and uninfected dogs revealed antigenic components of relative molecular mass (Mr) larger than 94,000, Mr 94,000-68,000 and Mr 43,000-39,000 in worms, and these were specific for E. granulosus and not identified in PSM; these antigenic differences may be responsible for differences in reactivity in ELISA. The sensitivities of W-ELISA and P-ELISA were 80.8% and 75.6%, respectively. The specificities of W-ELISA and P-ELISA were 93.7% and 97.9%, respectively. The reduced specificity in W-ELISA was mainly attributable to increased background reactivity of sera from Taenia hydatigena-infected dogs. Despite the reduction in specificity, both ELISAs are valuable epidemiological tools to determine the prevalence of antibody to E. granulosus in dog populations and to monitor the success of hydatid control campaigns.  相似文献   

13.
In a previous study, Giardia infection patterns were studied in newborn dairy calves over a 4-month period. Chronic Giardia infections were observed in all calves with initial cyst excretion occurring at approximately 1 month of age. In the work presented here, the passive immunity and serological immune response associated with these Giardia infections were examined. Colostrum and milk samples were collected from the dams of these calves, and monthly serum samples were collected from each calf. The colostrum, milk and sera samples were analyzed by ELISA and Western blot for the presence of anti-Giardia IgG antibodies. In addition, the in vitro anti-Giardia activity of milk and colostrum was examined using a miniculture adherence assay. When examined by ELISA, mean anti-Giardia antibody titres were found to be significantly higher in colostrum compared to milk. The monthly mean serum antibody titres in the calves were not found to differ significantly at any time point during the study. Western blot analysis revealed that colostrum from the dams reacted strongly with many different Giardia antigens between 205 and 7.5kDa, while milk reacted with few antigens in the same size range. Sera collected from the calves when 30 and 60 days of age reacted with few Giardia antigens, but as the calves aged, IgG antibodies in their sera began to react with antigens of 21, 50, 65, 73 and 79kDa. The miniculture adherence assay demonstrated that colostrum had significantly more anti-Giardia activity in vitro compared to milk. These results suggest that the calves in this dairy did not mount a significant humoral immune response against Giardia following infection. However, colostrum contained a high level of anti-Giardia antibodies and exhibited anti-Giardia activity in vitro. Therefore, colostrum may have the potential to provide initial protection against Giardia infections in calves, but the lack of a strong, specific humoral immune response by these calves could account for the high prevalence and chronic duration of the infections.  相似文献   

14.
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   

15.
Serum samples from healthy dairy and beef cattle, living in tick-infested areas of Connecticut, USA, were analyzed by polyvalent enzyme-linked immunosorbent assays (ELISA), indirect fluorescent antibody (IFA) staining methods, or Western blot procedures to detect antibodies to tick-borne agents. Of the 80 sera tested by ELISA with whole-cell or 10 separate recombinant antigens (fusion proteins) of Borrelia burgdorferi sensu stricto, 57 (71%) were positive to 1 or more antigens, while 36 (45%) reacted to whole-cell antigens by IFA staining methods. Three (4%) of 80 samples had antibodies to Anaplasma phagocytophilum. There were antibodies to outer surface protein (Osp) A, OspB, OspC, OspE, OspF, protein (p) 41-G, p35, p37, and VlsE antigens of B. burgdorferi, but there was no reactivity to the p39 antigen by ELISA. Western immunoblots of a subset of 9 sera verified antibody presence in all samples and showed distinct reactivities to multiple proteins having molecular masses of about 31 kilodaltons (kDa), 34 kDa, 35 kDa, 41 kDa, and 83/93 kDa. High specificity (97%) was noted when 16 cattle sera containing antibodies to Leptospira interrogans serovars, Brucella sp., Anaplasma marginale, or A. phagocytophilum were tested by ELISA with separate whole-cell or recombinant B. burgdorferi antigens. An ELISA and Western blot analyses can be used to confirm the exposure of cattle to B. burgdorferi.  相似文献   

16.
Enzyme-linked immunosorbent assay (ELISA) is compared with the indirect fluorescent antibody test (IFAT), the indirect haemagglutination test (IHAT) and the latex agglutination (LA) test for the detection of toxoplasma antibodies in swine sera. The 100 swine sera examined represent ELISA values from greater than 0 to 154 EIU. The agreement was highest (0.67) between ELISA and IFAT with an ELISA cut-off value of 30 EIU, and between ELISA and the LA test with an ELISA cut-off value of 50 EIU (0.74). All sera giving less than 10 EIU were negative in the other tests, and all those with greater than 70 EIU were positive in 1, 2 or all of the reference tests. In order to avoid false positive results with ELISA, all sera giving 10-70 EIU should be confirmed with a test which has a good specificity, e.g. IFAT. ELISA is a sensitive test and is highly suitable for the screening of large amounts of samples, but it may be too complicated for screening toxoplasma antibodies in the laboratories of abattoirs.  相似文献   

17.
Infectivity and antigenicity of Anaplasma marginale from tick cell culture   总被引：1，自引：0，他引：1  
The infectivity and immunogenicity of Anaplasma marginale grown in a tick cell culture from embryonic Dermacentor variabilis ticks were assessed in splenectomized and intact calves, respectively. Culture 1 consisted of the cell line inoculated with midguts of adult ticks infected with the Mississippi isolate of A marginale and dissected 5 to 10 days after repletion and detachment from an experimentally infected calf. Cultures 2 and 3 consisted of the cell line inoculated with midguts of ticks infected with the Virginia isolate of the organism. Inoculum for culture 2 was derived from nymphal ticks dissected 5 to 10 days after repletion and detachment from the infected calf; inoculum for culture 3 was midguts from adult ticks that were fed as nymphs, allowed to molt in the laboratory and dissected 21 to 24 days after molting. In trial 1, cultures 1, 2, and 3 were maintained at pH 6.9 and incubated at 28 C; in trial 2, cultures 1 and 3 were maintained at pH 7.4 and incubated at either 28 C or 37 C. Cultures 1, 2, and 3 failed to induce infection when injected IV and SC into 6 calves in 2 separate trials. Pre-challenge sera from these calves reacted with 2 purified Anaplasma antigens in the ELISA, but failed to react in the complement-fixation test. Results of a trial to use cultures 1 and 3 in combination with an oil-in-water adjuvant to immunize intact calves against A marginale were inconclusive. However, pre-challenge sera from immunized calves reacted with the 2 purified Anaplasma initial body antigens in the ELISA but failed to react in the complement-fixation text.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Dog sera (n = 118) were tested for antibodies recognizing Borrelia (B.) burgdorferi sensu stricto strain B31 (ATCC 35210) antigens. In total, 18 of the dog sera gave positive results in a whole cell sonicate ELISA (WCS ELISA). These positive sera were further evaluated by immunoblot assay, utilizing a whole bacterial lysate as antigens. 94.4% (17 of 18) of the dog sera reacted with immunodominant antigens at 20-22 kDa (protein C, pC), 31 kDa (outer surface protein A, OspA), 34 kDa (outer surface protein B, OspB), 41 kDa (flagellin), 60 kDa ("common antigen"), and/or 100 kDa (presumably p100). Sera recognizing pC (20-22 kDa) and antigens > 94 kDa always detected the highest number of antigen bands, indicating the specificity of those antigens in serological diagnosis. The results clearly demonstrate that the WCS ELISA is a useful tool for testing sera of dogs for antibodies against B. burgdorferi. However, positive results should be confirmed by immunoblot, using WCS as antigen. According to the presented data, we recommend criteria for B. burgdorferi immunoblots using dog sera as follows: sera have to be considered as positive if they detect the 41 kDa flagellin, and two of the 5 immunodominant antigens, namely > 94 kDa (presumably p100), 60 kDa ("common antigen"), 34 kDa and 29-31 kDa (OspB and OspA, respectively) and 20-22 kDa (pC). If sera only recognize the 41 kDa flagellin, this result is equivocal, requiring testing a second serum sample 4 to 8 weeks later.  相似文献   

19.
Cathepsin L cysteine proteinase from Fasciola gigantica was evaluated for its potential in the early prepatent detection of this helminth infection in bovine calves. Five cross-bred bovine calves were experimentally infected with 400 metacercariae/calf and evaluated for anti-cathepsin L antibody response. F. gigantica infection in these calves could be detected 4 weeks post-infection using an ELISA, dipstick ELISA and Western blotting with 100% sensitivity. The antigen was also used to detect F. gigantica field infection in cattle, by screening 256 sera of these animals by an ELISA, which demonstrated an overall infection rate of 26.95%. Preliminary studies showed that F. gigantica cathepsin L cysteine proteinase does not cross-react with Paramphistomum epiclitum, Gigantocotyle explanatum and hydatid cyst antigens. However, extensive studies on the cross-reactivity of this antigen with related helminth parasites of cattle and buffaloes are required, before this antigen can be considered suitable for immuno-diagnosis of fasciolosis in these ruminants.  相似文献   

20.
ELISA was adapted for the study of antigenic relations among important Campylobacters and for the presence of anti-campylo-bacter antibodies in 394 sheep and 265 cattle. Rabbit anti-C. jejuni, C. coli, G. fetus subsp. fetus and C. laridis heat-stable antigen sera were evaluated against 29 Campylobacter strains and 6 other bacteria. Anti-C. jejuni and G. coli reacted strongly with homologous antigens and weakly with C. fetus subsp. fetus, C. laridis and C. fecalis antigens. C. fetus subsp. fetus serum reacted mainly with its homologous antigen. C. laridis serum showed closer reactivity to C. jejuni than to C. fetus subsp. fetus, C. coli and C. fecalis. Insignificant cross-reactions were observed with Y. enterocolitica, S. dublin and E. aerogenes heat-stable antigens, Ewes vaccinated with C. fetus subsp. fetus bacterin showed higher ELISA titers against C. fetus subsp. fetus antigens than non-vaccinated ewes or rams. Twenty-five percent of the vaccinated animals showed titers as low as 95 % of the non-vaccinated animals. In cattle the lowest antibody titers against C. fetus subsp. fetus, C. jejuni, C. coli and C. laridis antigens were exhibited by the precolostrum sera followed by the postcolostrum and adult sera. These studies demonstrated the applicability of the ELISA test in seroepidemiological investigations concerning the distribution and significance of Campylobacter antibodies in food animal sera.  相似文献   

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