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1.
The growth-inhibition test was used to detect specific antibodies against Leptospira interrogans serotype hardjo in isolated immunoglobulin (IgG and IgM) fractions of serums from cattle vaccinated with leptospiral bacterins. The growth-inhibiting antibodies were detected mainly in the IgG class. Agglutinated clumps also occurred with the IgM fraction. The serums collected from cattle 4 months after vaccination were negative in the microscopic agglutination test.  相似文献   

2.
Serum antibody responses in feral or domesticated dogs naturally infected with Echinococcus granulosus or/and other common helminths were examined in an enzyme-linked immunosorbent assay (ELISA) using antigens prepared from E. granulosus protoscoleces or oncospheres. The ELISA using the protoscolex antigen was optimised with serums from experimental dogs monospecifically infected with E. granulosus or other helminth parasites, and helminth-free dogs. Anti-protoscolex antibody was detected in 16 of 22 (72.7%) serums from feral dogs with E. granulosus burdens ranging from 300 to 302,600 worms per dog. Seven serums from feral dogs which did not harbour E. granulosus at autopsy but which originated from an endemic hydatid region were tested using protoscolex antigen, and 1 serum gave a positive reaction. One hundred and two serums from dogs known never to have been infected with E. granulosus all gave negative reactions to protoscolex antigen. The sensitivity of the ELISA test proved to be superior to that which has been achieved by arecoline purging as a method of diagnosis for E. granulosus infection in dogs. For use of the assay in hydatid control or eradication campaigns, its sensitivity can be increased by choosing a lower absorbance discrimination value above which serums are regarded as having positive reactions. However, this does introduce positive reactions of some serums from dogs infected with helminths other than E. granulosus. In further development of the assay, use of defined recombinant antigens may improve both sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
From June 1971 to June 1972, sera from 600 dogs in Sydney were tested for leptospiral agglutinins by a rapid slide agglutination method. The end-point titre was taken at 50 percent agglutination of the live organisms. Forty-one samples (6.8 percent) had a significant leptospiral titres (100 or greater) and 5 of these reacted to 2 serotypes. Thirty serums (5 percent) contained agglutinins against L. copenhageni, and 6 (1 percent) against L. pomona, while a few samples reacted against hardjo, tarassovi, australis, grippotyphosa or pyrogenes serotypes. No significant titres were found to L. canicola, L. hebdomadis, L. autumnalis or L. bataviae.  相似文献   

4.
Serological surveys of leptospiral antibodies in cattle were carried out in Macon and the surrounding counties of East Central Alabama. A total of 286 bovine serum samples were screened for the presence of antibodies against live antigens from twelve pathogenic leptospiral serotypes using a microscopic agglutination test. The most frequently encountered serotypes were Leptospira hardjo (47%), Leptospira wolffi (34%), Leptospira canicola (12%), Leptospira pomona (10%) and Leptospira ballum (10%). Leptospira autumnalis, Leptospira grippotyphosa, Leptospira icterohemorrhagiae, Leptospira pyrogenes and Leptospira tarassovi were observed in less than 5% of the samples.  相似文献   

5.
A complement fixation (CF) test, 2 indirect haemagglutination (IHA-A; IHA-L) tests which differed in antigen preparation and technique, and a microtitre agglutination (MA) test were compared in the serodiagnosis of melioidosis in goats. One hundred and eighteen experimental serums and 3143 field serums from goats in endemic and non-endemic areas of north Queensland were used in the evaluation. Culture of samples for Pseudomonas pseudomallei from 112 goats provided substantiating evidence of infection. The IHA-A test was the most sensitive, and the CF test the most specific. We advocate the use of the IHA-A as a screening test followed by the CF test for confirmation of active melioidosis. The IHA-A test is the better indicator of past infection.  相似文献   

6.
In a serologic survey of stray and pet dog populations of Georgia, serums were screened for Brucella canis antibodies, using the slide agglutination test. If results were positive, B canis antibody titers were determined, using the standard tube agglutination test. The stray dogs had significantly (P less than 0.01) higher titers than did the pet dogs. The reactor rate was 58% higher for the slide agglutination test than for the tube agglutination test. The manufacturer's evaluation of the slide agglutination test was based on a comparison of the serologic results of that test with those of the tube agglutination test, using a comparative method that permitted the results to be interpreted as 99% agreement between the 2 tests. Reevaluation of the manufacturer's data by a different method indicated that the slide agglutination test is very accurate when the results are negative (99.7% specific) but less so when the results are positive (62.5% sensitive).  相似文献   

7.
A latex agglutination test for detecting Echinococcus multilocularis coproantigen in definitive hosts was developed using latex beads sensitized with EmA9 monoclonal antibody raised against somatic antigens of adult E. multilocularis. A primary test (LA 1) was performed on 82 fecal samples of necropsied foxes, of which 46 were infected, and resulted in 61% sensitivity and 86% specificity. To increase the sensitivity, 4 ng/mL of excretory/secretory antigens of adult worms was added to the samples in a secondary test (LA 2), resulting in 91% sensitivity and 61% specificity. The positive predictive value of the LA 1 test and the negative predictive value of the LA 2 test were both 85%. The combination of the LA 1 and LA 2 tests is applicable and practical for use in situations that require quick diagnosis or screening based on the following interpretation: the samples that are positive in the LA 1 test are positive; the samples that are negative in the LA 2 test are negative; and the samples that are negative in the LA 1 test and positive in the LA 2 test are classified as suspicious.  相似文献   

8.
A serological survey was carried out to detect specific (serotype 20) and a group bluetongue virus antibody in cattle and sheep serums collected in Western Australia during the period January 1 1978 to June 30 1979. Of 18,849 cattle serums examined by the gel diffusion precipitin test (GDPT), 9.7% were positive and 6.1% gave doubtful results. All 1949 sheep serums tested were negative. Precipitin antibody was demonstrated in 22.5% of serums from Kimberley cattle and 3.6% of cattle serums from the Northwest. Serums collected from cattle in the South were consistently negative in GDPT. When 915 serums that reacted in the GDPT were further tested by the complement fixation test (CFT), 164 were positive. The percentage of CFT positive serums increased as the GDPT reaction became stronger. 2467 serums collected from cattle in Kimberley and Northwest areas and tested by the CFT, 175 (7.1%) were positive. These 175 positive serums were also examined by GDPT and 164 doubtful or positive reactions were obtained. The virus neutralisation (VNT) using serotype 20 virus was carried out on 3804 serums, including all serums that reacted in the GDPT, and 57 were positive. When the VNT positive serums were examined in the other 2 tests, 47 serums were either positive or doubtful in the GDPT and 8 were positive in the CFT. The presence of bluetongue virus group antibody in cattle serums closely followed the suggested distribution pattern of Culicoides brevitarsis but specific serotype 20 neutralising antibody was limited to cattle serums from stations situated north of latitude 17 degrees S in an area of mean annual rainfall higher than 700 mm.  相似文献   

9.
A capillary agglutination (CA), a complement fixation (CF), a plate agglutination (PT) and an indirect fluorescent antibody (IFA) test to detect humoral antibodies to Anaplasma marginale are described. Serums from 3, 4 or 5 groups of cattle were used to examine the efficiency of the tests. Agreement between all 4 tests was 86.6%. Agreement between pairs of tests was greater. The CF test was the most sensitive while the PT test was the least sensitive. However the PT could be carried out very rapidly and was suggested as the best screening test, providing improved antigen preparation techniques could increase sensitivity. The CA, CF and IFA tests all showed a stronger homologous antibody reaction when A. marginale antigen was tested against serums obtained from cattle infected with either A. marginale or A. centrale. Antibodies in the A. marginale serums were first detected by day 7 post-inoculation, rose to peak around day 29 and were still present on day 200. Antibodies in the A. centrale serums were first detected by day 29 rose to a peak around day 50 and had disappeared by day 150.  相似文献   

10.
The aim of this study was to examine the utility of immunohistochemistry (IHC) in the diagnosis of leptospiral equine abortion and to compare IHC to silver staining and serology of the aborted mares. Ninety-six fetuses from 57 farms were examined using all 3 diagnostic techniques, revealing evidence of leptospiral infection in 3 fetuses (3.1%) from 3 (5.3%) different farms. A new finding in 1 of these confirmed cases of leptospiral abortion was the presence of macroscopic pinpoint grayish-white nodules that had a histologic correlate of hepatic necrosis; other histologic findings were consistent with those previously reported. IHC performed using 2 different leptospiral antisera (multivalent whole-cell rabbit antiserum and rabbit antiserum against the major outer membrane protein LipL32) yielded similar results. IHC was more sensitive (19/21 [90.5%] tissue samples) than silver staining (8/21 [38.1%] tissue samples), and more specific than serology performed using the microscopic agglutination test. The primary advantage of IHC over silver staining was the ability of IHC to identify leptospiral antigen not only as morphologically intact spiral forms.  相似文献   

11.
Autoantibodies to thyroid antigens in serums from 34 clinically hypothyroid dogs were detected by various methods. Antibodies to thyroglobulin were detectable by enzyme-linked immunosorbent assay (ELISA) in 59%, by chromic chloride hemagglutination in 53% and by indirect immunofluorescence on formalin-fixed, paraffin-embedded, trypsin-digested thyroid tissue in 73% of samples. Antibody to thyroid microsomal antigen was detectable by ELISA in 29% of serums. Indirect immunofluorescence showed cytoplasmic fluorescence of thyroid follicular cells in several serums, however, this could not be confirmed as specific for microsomal antigen by absorption trials. Hemagglutination tests using commercially available tanned red cells coated with human antigens and indirect immunofluorescence assays on formalin-fixed tissue without trypsin digestion, on Bouin's fixed tissue, or on cryostat, methanol-fixed sections, were insensitive. Cryostat sections without methanol fixation were unsuitable due to tissue fragility. No method was recommended for routine diagnostic use. The ELISA test, because of its convenience, may be useful as a screening aid or adjunct to the diagnosis of thyroid disease.  相似文献   

12.
Three hundred and thirty-eight sera collected from stray dogs in the Okinawa islands were examined for antibodies against Leptospira interrogans using the microscopic agglutination test (MAT) and the one-point microcapsule agglutination test (MCAT). Seventy-eight sera (23%) showed a positive reaction to at least one of the six serovar antigens, and 69 of these reacted with serovar canicola by microcapsule agglutination test. The mixed microcapsule agglutination test detected 68 of the microscopic agglutination test-positive sera, and the 10 remaining were negative by microcapsule agglutination test. On the other hand, a single microcapsule agglutination test which was sensitized with serovar canicola detected 77 of the microscopic agglutination test-positive sera and the remaining one was microcapsule agglutination test-negative.  相似文献   

13.
An ELISA utilising a urease-antibody conjugate specific to chicken IgG was examined as an alternative to the serum agglutination and the haemagglutination inhibition tests in the diagnosis of Mycoplasma gallisepticum and M. synoviae infections in poultry. Use of a urease conjugate allowed the serum reactions to be appraised without the need for expensive photometric equipment. Non-specific binding of conjugate to antigen was eliminated by treatment of antigen coated microplates with 10% foetal calf serum in phosphate buffered saline. Some chicken serums produced non-specific reactions. These reactions were reduced without any loss of test sensitivity by making the initial 1:5 dilution of chicken serum in whole sheep serum rather than diluting buffer. Tests on serums from experimentally infected chickens showed that the urease ELISA was specific, and was as sensitive as the serum agglutination test but more sensitive than the haemagglutination inhibition test.  相似文献   

14.
A total of 1,355 random samples taken from bovine serums submitted for brucellosis testing in Victoria were submitted to the microscopic agglutination test for the presence of antibody to 12 serovars of Leptospira interrogans . The most common reaction obtained was to serovar hardjo , although the percentage of reactors varied from 24.8% in the metropolitan area to 56.3% in north-eastern Victoria (mean 40.6%). A total of 86.3% of farms from which 3 or more samples were taken had at least one reactor to serovar hardjo . The prevalence of antibody to other serovars was tarassovi (7.8% of reactors), ballum (3.7%), pomona (2.4%), autumnalis (1.8%) and bataviae (1.2%). Reactions to other serovars were observed in serums of less than 1% of cattle tested; serums from 50.8% of cattle did not react to any antigen.  相似文献   

15.
Five different antigens were evaluated in enzyme-linked immunosorbent assay (ELISA) tests for the detection of avian pneumovirus (APV) antibodies. Two of the 5 antigens were prepared from recent APV isolates from Minnesota. The 2 older isolates were passage 63 of a strain currently used as a live, attenuated vaccine and a Colorado strain isolated for the first time in the United States and currently used in an ELISA test. The fifth antigen is based on an APV recombinant N-protein. Basic parameters and positive-negative threshold of the assays were established for all 5 antigens on the basis of data obtained by testing 46 known negative and 46 known positive serum samples. Subsequently, 449 field samples were tested by all 5 ELISAs. The optical density difference (ODD) was calculated by subtracting optical density of the sample in the negative antigen well from that in the positive antigen well. In the current ELISA test based on the Colorado strain, an ODD of 0.2 is considered to be the cutoff value to classify samples as negative or positive. In this study, however, use of different cutoffs, based on ODD of negative control plus 3 SD or values estimated from Receiver operating characteristic analysis, was considered to be more appropriate for the various antigens used. Overall person-to-person and day-to-day variability was found to be large for all tests using either ODD or sample to positive ratio to report results. In addition, results suggest that antigenicity of the APV isolates in the United States has not changed between 1997 and 2000.  相似文献   

16.
A recombinant leptospiral lipoprotein, LigB, was evaluated for use in the diagnosis of bovine leptospirosis by enzyme-linked immunosorbent assay (rLigB IgG ELISA). The standard reference test (Microscopic agglutination test, MAT) of 200 serum samples from cattle suspected of leptospirosis showed that 95 (47.5%) samples had positive agglutination titres, which ranged from 100 to 1600. In rLigB IgG ELISA, 49% of the samples were positive. Sensitivity of IgG ELISA for 95 bovine sera, which had MAT titres of greater than or equal to 100, were 100%. ELISA showed a specificity of 97.1% with 105 bovine sera, which were negative at a 1:50 dilution in MAT for Leptospira interrogans serovars. The results of ELISA and MAT correspond very good. When analytical specificity of IgG ELISA was evaluated using bovine serum samples from animals showing the serum antibodies to other pathogens, no cross-reaction was observed. Thus the recombinant LigB IgG ELISA can be used instead of the MAT as an aid to the diagnosis of bovine leptospirosis.  相似文献   

17.
A microimmunodiffusion test (MIDT) was developed for the detection of pseudorabies virus (PRV) antibodies in swine serum. The optimal medium for the MIDT was determined to contain 0.69% agarose in 0.05 M tris buffer (pH 7.2) with 0.025% sodium azide and no NaCl. The PRV antigen prepared by (NH4)2SO4 precipitation of viral fluids (42.5 g/100 ml), dialyzed against distilled water, and concentrated to approximately 100-fold of the original volume with polyethylene glycol (mol wt 20,000) provided a good reproducible antigen. The sensitivity of the MIDT was compared with the microtitration procedure of the virus-neutralization (VN) test by assaying 2,203 swine serums for PRV antibodies. An equal percentage of serums was positive in both tests; 419 had VN titers of greater than or equal to 4, and 421 were MIDT positive. Serums (314) that had VN titers of greater than or equal to 16 were all positive by the MIDT. Of serum samples with a VN titer of 8 (53), 50 were MIDT positive, a 94% correlation, and of 52 serums that had VN titers of 4, 36 were MIDT positive, a 69% correlation. In addition, 8 serums that had titer of less than 4 by VN test were positive by MIDT. Seventy-one serum samples were too cytotoxic, markedly hemolyzed, or contaminated to evaluate properly in the VN test; of these serums, 13 were MIDT positive. The MIDT is an accurate, rapid, economical, and sensitive diagnostic test for the detection of PRV antibodies in swine serums.  相似文献   

18.
The use of a phosphate-buffered horse-meat infusion broth (pH 7.8) containing neomycin sulphate 50 pg/ml, kanamycin 400xg/ml and vancomycin 25 pg/ml was compared with the medium without antibiotics in the E. insidiosa growth-agglutination test on sterile and contaminated, positive and negative swine and rabbit serums.The addition of the inhibitory agents to the medium caused no visible growth depression on the 2 antigen strains employed — regardless of the percentage (S 40 %) of specific hyperimmune serum content.The use of the selective medium in testing hyperimmune serum revealed no significant difference in the recorded antibody titer as compared to the ordinarily used medium. The presence of some contaminants in the agglutinating system did not influence the results — provided that the multiplication of these organisms was inhibited (Table 1).The inhibitory efficiency was tested on 161 contaminated sw’ine serum samples and on 12 contaminated rabbit serums. None of the selective broth dilutions of these serums showed multiplication of contaminants during a 24 hrs. preincubation period or in a control tube after 48 hrs. incubation.The inhibitors allow bacteriologic aseptic technique in the procedure of the growth-agglutination test to be deviated to a certain limit. This limit was not exceeded in this material by applying a serum dilution technique otherwise used in agglutination tests with killed antigen.As the described method eliminates the demand of complete aseptic bleeding and serum preparation procedures or an elaborious sterile filtration procedure, and since the test can be used by any laboratory without previous preparation and testing of a killed antigen, the growth-agglutination test is recommended as a fast and reliable aid in the differential diagnosis of erysipelas arthritis on herd basis in swine.  相似文献   

19.
In cows inoculated with Leptospira interrogans serovar pomona or hardjo, the 2-mercaptoethanol-sensitive microscopic agglutination test (MAT) antibody to the serovar appeared 3 to 8 days after inoculation and peaked at 10 to 20 days, whereas the 2-mercaptoethanol-resistant MAT antibody was predominant at 35 to 80 days. A persistent antibody response, probably associated with serovar-specific leptospiral antigens, was detected in the cows inoculated with serovar pomona, using a sonicated or an alkaline-extracted antigen derived from serovar pomona in the enzyme-linked immunosorbent assay (ELISA). In contrast, a short-lived antibody response to the same antigens was demonstrated in cows inoculated with serovar hardjo, probably more typical of the response to genus-specific leptospiral antigens. Antigens derived from L biflexa serovar patoc only detected the latter type of antibody response in cows inoculated with serovar pomona or hardjo. Correlative studies revealed that the antigens derived from serovar patoc seem to be genus specific and serologically closely related, but not identical. The antigens derived from serovar pomona were genus specific on the basis of the early antibody response to leptospiral inoculation in the cows, but serovar specific based on the subsequent more persistent response to leptospiral inoculation. These antigens were also serologically closely related, but not identical. Examination of sera from cows that aborted and were MAT-positive for serovar pomona or hardjo revealed a more serovar-specific antibody response, indicating that there may have been a less recent leptospiral antigenic stimulus, thus emphasizing the caution with which results of the ELISA and other serologic assays for the detection of bovine leptospirosis must be interpreted.  相似文献   

20.
This study documents the examination of 17 horses (both sexes, 3-18 years old) suffering from spontaneous equine recurrent uveitis (ERU). Vitreal samples obtained by pars plana vitrectomy were examined macroscopically and ultrastructurally, and in most cases also by cultural examination, by microscopic agglutination test (MAT) and by polymerase chain reaction. In 24% (4/17) of the animals, ultrastructural examination by electron microscopy revealed intact leptospiral bacteria in the vitreous. The leptospires were detected freely in the vitreous and also incorporated by a phagocyte. They were surrounded by a rim of proteinaceous material which was reduced around a phagocytosed leptospira. Ninety-four per cent (16/17) of the vitreal samples presented significant antibody levels in the MAT, mostly against leptospiral serovar Grippotyphosa. Seventy-five per cent (9/12) of bacterial culture examinations were positive for leptospira. Polymerase chain reaction was positive in all (16/16) examinations performed. Our findings support previous reports suggesting that leptospires play an important role in the pathogenesis of ERU. Interestingly, this study found leptospires after secondary and later acute episodes. A persistent leptospiral infection is therefore suggested as the cause of ERU.  相似文献   

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