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Profiles of serological reactions following adult cow inoculation with standard dose Brucella abortus strain 19 vaccine.

Experimental use of the standard dose (4-12 X 10(10) viable organisms per dose) Brucella abortus strain 19 vaccine (S19) in adult cattle led to a serological response in the complement fixation test (CFT) within 2 weeks. The antibody titres recorded could not be distinguished from those arising from infection for a period of 6-11 months. This was in the absence of the booster effect of Brucella antigen from either field or vaccine strains. The illegal or unintentional use of S19 in adult cattle may be recognized by a sudden steep antibody titre response in the CFT which will decline to negative levels within 6-11 months provided no booster Brucella antigen is present.

Agglutination Tests↗

Comparison of enzyme-labeled immunosorbent assay and particle concentration fluorescence immunoassay with standard serologic methods and bacteriologic culture for detection of Brucella sp-infected cows in herds with brucellosis.

Bacteriologic culture of udder secretions and card, rivanol, and complement fixation tests for detection of brucellosis were performed on samples from 828 cows vaccinated with strain 19 in herds with brucellosis. An ELISA and a particle concentration fluorescence immunoassay were performed on sera from 560 and 569 cows, respectively. A field strain of Brucella abortus or strain 19 was isolated from 278 cows. The ELISA and the card test had high sensitivity, but low specificity. Data suggested that there is no advantage to using primary binding assays rather than the simple buffered antigen agglutination procedures to detect cows infected with a field strain of B abortus.

Agglutination Tests↗

The antibody response to the flagella of Pseudomonas aeruginosa.

Mutants lacking flagella or fimbriae (pili) or both were used for the preparation and absorption of rabbit antisera against the flagella of Pseudomonas aeruginosa. The results of agglutination, immobilisation and complement-fixation tests indicate that the antisera obtained are specific for flagella. The incorporation of nitrate into semi-solid agar for motility and immobilisation tests was found useful for the selection of activity motile cells and for the demonstration of specific antibody to flagella.

Agar↗

[Immunological diagnosis of cytomegalovirus infections. Application to blood transfusion centers].

The Blood Transfusion Centers (B.T.C.) are mainly concerned with the selection of CMV infection free blood donors, the screening of the anti CMV antibody high titre plasma donors and the evaluation of specific anti CMV Immunoglobulin preparations. Various serological methods could be used but they are of different value depending the purposes of the B.T.C. The neutralization test (Nt), with the addition of complement is specific and detects the protecting AB against the glycoproteins of the viral envelope. The complement fixation test (CF) using extracts of CMV infected cells as antigen largely varies in its sensitivity according to the quality of the antigen. In any case, the CF test is not sensitive enough to detect a latent CMV infection in a certain percentage of the non immunosuppressed adults, but could be used for the selection of anti CMV antibody high titres carriers. Three sensitive methods: passive haemagglutination, indirect immunofluorescence and indirect ELISA tests, might be used for the detection of latent CMV infections. They detect various AB against various internal and external components of the CMV. They are submitted to various sources of errors. The sensitivity of the indirect IF test is mainly restricted by the quality of the antigen preparation, its specificity by the presence of anti cells antibodies in the sera, the Fc receptors in the antigens and the specificity of the conjugates. The indirect ELISA which is submitted to the same causes of errors is a highly sensitive test, easy to perform, reagents are available, and automatic processors have been developed. When compared with the previous techniques, the ELISA test is suitable for the screening of CMV free donors, when it is performed with an highly sensitive antigen. It could be also used for the screening of high antibody titre carriers: its correlation with the CF test is quite good (r = 0,82). When comparatively applied to the titration of Immunoglobulins preparations, made from plasmas or placentas, for either IM or IV administration, the Elisa test gives AB titres different from those obtained with Nt and indirect IF. The calibration of a standard Immunoglobulin reagent is urgently needed and double blind clinical assays of the protective effect of various preparations of specific anti CMV Immunoglobulins have to be promptly designed.

Antibodies, Viral↗

Immunodiffusion analysis of Yaba poxvirus structural and associated antigens.

Yaba poxvirus virions were extracted and purified from Rhesus monkey tumors. A saline-soluble virion fraction (Y-xp), obtained by mechanical fractionation of purified virions with an X-press, contained seven components in acrylamide gel electrophoresis; five of these components were reactive in immunodiffusion with whole virion and Y-xp antisera produced in rabbits and monkeys. The saline-insoluble residue remaining after X-press treatment was hydrolyzed with sodium dodecyl sulfate, urea, and 2-mercaptoethanol (SUM). This fraction, Y-sum, contained five components, four of which were demonstrable by immunodiffusion. There was no evidence of antigenic relationships between Y-xp and Y-sum antigens in immunodiffusion. In acrylamide gel electrophoresis, one Y-xp and one Y-sum component had similar mobilities. Y-xp but not Y-sum antisera contained viral-neutralizing antibodies. Virus-free saline extracts of Yaba tumor prepared with Genetron (YS) were essentially devoid of virion structural antigens. They failed to induce precipitating antibodies for virion antigens, were nonreactive in immunodiffusion with virion antisera, and gave low complement-fixation titers with virion antisera. Yaba virion antigens were recovered from the Genetron tumor sediment by SUM and alkaline hydrolysis. Antisera prepared to YS extracts gave a maximum of 17 precipitin lines in immunodiffusion with YS extracts; none was identified as a virion structural antigen. Saline extracts of tumor prepared without Genetron contained immunogenic amounts of 5 virion antigens and 12 to 14 associated antigens. Animals immunized with infected cell culture extracts (virus-free) formed antibodies to six to seven virion antigens. The implications of using extracts of Yaba poxvirus-infected tissues in complement-fixation tests to measure virion antibodies were discussed.

Animals↗

Comparison of three serological tests and an interferon-gamma assay for the diagnosis of paratuberculosis in experimentally infected sheep.

OBJECTIVE: To compare the diagnostic performance of a complement fixation test, an agar gel immunodiffusion test, an enzyme-linked immunosorbent assay, and a whole-blood interferon-gamma assay for paratuberculosis in 14 sheep experimentally infected with Mycobacterium avium subsp paratuberculosis. EXPERIMENTAL DESIGN: Longitudinal study. RESULTS: The IFN-gamma assay detected more experimentally infected sheep, and earlier, than any of the serological tests. None of the antibody assays was able to detect all sheep with histologically confirmed paratuberculosis. CONCLUSIONS: The superior performance of the IFN-gamma assay in detecting infected sheep in this small experimental population warrants its further evaluation in a larger population of sheep naturally exposed to M a paratuberculosis.

Animals↗

Immunoassay for serologic diagnosis of influenza type A using recombinant DNA produced nucleoprotein antigen and monoclonal antibody to human IgG.

Influenza type A nucleoprotein (NP) derived from the full length cloned gene expressed in E. coli was evaluated in a solid phase enzyme immunoassay (EIA) for detection of human antibody to influenza. Monoclonal antibody to human IgG was used for detection. Direct and indirect assays were developed and sera were tested in serial and single dilution formats. Preliminary results indicated that recombinant-and virion-derived NP antigens were comparable in binding ability to plastic and binding human antibody. Eighty-seven paired sera from influenza patients were tested. The most sensitive assay (indirect-serial dilution) detected 56 (64%) rises and the simplest assay (direct-single dilution) detected 43 (49%) rises, compared to 36 (41%) for complement fixation. Paired sera from 18 control patients showed no evidence of antibody rises by any of the assays. Forty-nine paired sera from influenza B infected patients were negative for antibody rises except for one borderline rise by the indirect-serial dilution assay. These results indicate that the use of recombinant DNA derived nucleoprotein for immunoassay is feasible. The sensitivity of immunoassays using NP adsorbed to the solid phase and monoclonal antibody specific for human IgG to detect bound antibody exceeded that of conventional complement fixation testing for establishing serologic evidence of influenza type A infection.

Antibodies, Monoclonal↗

A comparison of serological tests and gross lung pathology for detecting contagious bovine pleuropneumonia in two groups of Italian cattle.

Western and dot blotting techniques were compared with complement fixation tests (CFT), indirect enzyme-linked immunosorbent assays (ELISA), mycoplasma culture and gross lung pathology to detect Mycoplasma mycoides subspecies mycoides SC, the cause of contagious bovine pleuropneumonia (CBPP), in two groups of Italian cattle. None of the animals showed any clinical signs before slaughter. In group A, seven of the 20 cattle had characteristic lung lesions of acute and chronic CBPP but only six were positive by CFT. Western blotting detected antibody in eight of the animals, of which six had lesions and significant CFT titres (> 50 per cent fixation at a serum dilution of 1/10) and two had neither. In group B, seven of the 17 cattle had lesions characteristic of CBPP, and 12 were seropositive by CFT. Western blotting detected antibody in 13 of the animals including one which had a negative CFT titre. The ELISA was less sensitive than either CFT or Western blotting, detecting antibody in five animals in group A and nine animals in group B. The dot blotting test correlated well with Western blotting but gave a small number of ambiguous results. The causative organism was isolated from four of the 20 cattle in group A and six of the 17 cattle in group B.

Animals↗

The bovine immune response to Brucella abortus. III. Preparation of antisera against a Brucella component precipitated by sera of some infected cattle.

Two methods are described for the partial purification of a high molecular weight, heat-resistant component (CO1) of sonicates of smooth and rough Brucella abortus which is precipitated by sera of some infected cattle. Method 1, a combination of gel filtration chromatography and polyacrylamide gel electrophoresis, was used to prepare CO1 from sonicates of a smooth field strain of B. abortus. Method 2, a combination of gel filtration chromatography and heat treatment, was used to obtain CO1, from sonicates of rough B. abortus strain 45/20. Rabbit antisera produced against CO1 prepared by either method contained only CO1 precipitins but were negative in standard agglutination and complement fixation tests conducted with whole cell antigens. Evidence is presented that CO1 is identical to Brucella antigen A2, and it is proposed that in future the designation A2 be employed.

Agglutination Tests↗

Detection of chlamydial antibodies in animal sera by double diffusion in gel.

Postinoculation sera collected from pigeons, turkeys, guinea pigs, sheep, a calf, a rabbit, and a horse experimentally infected with various strains of Chlamydia psittaci yielded a high incidence of positive reactions when tested by double diffusion in gel. Antigen was a deoxycholate extract of SA-2 strain of C. trachomatis. Good correlation was obtained with results of complement fixation tests, whereas double diffusion in gel was less sensitive. Immunoelectrophoresis of the antigen revealed presence of two antigens in the extract.

Animals↗

[The occurrence of Coxiella burnetii in sheep and ticks of the genus Dermacentor in Baden-Wuerttemberg].

This study examined the occurrence of Coxiella burnetii (C. burnetii), the infectious agent of Q-fever, in sheep and sheep-ticks in Baden-Wuerttemberg, Germany, as a possible source of infection in Q-fever outbreaks. Using PCR, we examined a total of 1066 Dermacentor ticks from 23 herds and 49 samples of tick excrement from 18 herds for C. burnetii. We found the infectious agent in one non-engorged tick and in one sample of tick excrement from the same herd, in Efringen-Kirchen (district Loerrach). Sequencing the PCR-products confirmed the amplifications as specific for C. burnetii. Further serological tests of random samples of the four districts of Baden-Wuerttemberg showed a seroprevalence from 0 to 1.4% using complement fixation test (CFT), as well as a 0.9 to 10.2% seroprevalence, using ELISA test. Serum samples from a Q-fever-suspicious herd resulted, however, in 6% (CFT) and 53% (ELISA) positive reactions. A comparison between CFT and ELISA showed both a correlation of the two test methods that increased with higher CFT titration levels and positive reactions using ELISA for 9.4% of the serums that had tested negative using CFT. The results of the present study reveal that ticks and their excrements are important vectors of transmission of Q-fever in Baden-Wuerttemberg. Investigations on C. burnetii using PCR as well as serological surveys of sheep are important instruments for diagnosis and disease control of Q-fever.

Animals↗

Adeno-associated virus in adenovirus type 3 conjunctivitis.

Although human infection with adenovirus-associated virus (AAV) has been demonstrated, there is no evidence that disease results from such infections. The proportion of adenovirus infections which are dual infections with AAV is virtually unknown, since special methods are required to demonstrate infection with AAV. To search for AAV, we re-examined a collection of specimens from 40 persons involved in an epidemic of pharyngoconjunctival fever associated with a swimming pool. Virological and serological studies indicated that the etiological agent was adenovirus type 3. When the 91 original eye, throat, and fecal specimens were re-examined, using methods suitable for detection of adenovirus and AAV, 37 strains of adenovirus type 3 and 35 strains of AAV type 3 (AAV3) were isolated. Surprisingly, 19 AAV3 but only 11 adenovirus isolates were found in eye specimens, whereas adenovirus isolates were equally distributed in all types of specimens. Four AAV3 strains were isolated from adults. Significant (fourfold or greater) rises in AAV3 complement-fixing antibody titers were seen in six of 14 persons shedding AAV3, whereas nine of 10 persons shedding adenovirus type 3 showed significant rises in adenovirus complement-fixing antibody. These results raise the question whether AAV persists better in eyes than adenovirus or that a possible association with conjunctivitis might be present. In contrast to the results in the specimens from the swimming pool epidemic, only one of 36 adenovirus strains isolated in other Seattle-based studies yielded AAV. Complement fixation tests on serial sets of sera collected from 60 children not involved in the swimming pool episode revealed nine AAV2 and 12 AAV3 infections during a 4-year period.

Adenoviridae↗

Mycoplasma pneumoniae infections of adults and children.

Although the hallmark of Mycoplasma pneumoniae infection is pneumonia, the organism is also responsible for a protean array of other symptoms. With an increased awareness of the board clinical spectrum of M. pneumoniae disease and the ready availability of the cold agglutinin and M. pneumoniae complement-fixation tests, interested clinicians will note additional clinical-mycoplasmal associations in their patients.

Adolescent↗

Prevalence of antibodies to Haemophilus pleuropneumoniae in Iowa swine.

The prevalence of complement-fixing (CF) antibodies to Haemophilus pleuropneumoniae in Iowa swine was determined by testing samples collected randomly from each of 9 crop-reporting areas (9 to 12 counties) in Iowa in approximate proportion to the number of swine marketed annually from each area. For testing, a pooled antigen composed of serotypes 1 to 5 of H pleuropneumoniae was used in a modified direct Microtiter complement-fixation test. Of 7,348 sera tested, 2,362 or 32.1% had CF antibodies (titer greater than or equal to 1:4) to the organism. On a herd basis, 417 of 597 herds or 68.8% had at least 1 animal with CF antibodies (titer greater than or equal to 1:4) to the organism. The clinical problem with H pleuropneumoniae has become significant in recent years, but by no means is the overt disease as prevalent as animals or herds with CF antibodies to the organism.

Animals↗

Quantification of antimyosin antibodies in experimental myocarditis by a new solid phase fluorometric assay.

A solid phase fluorometric assay of high sensitivity and specificity for detection of antimyosin antibodies is described. The method consists of 4 basic steps: (1) coating the carrier stiQ with myosin; (2) incubation of the stiQ in the test serum; (3) labeling of the bound antibodies by FITC-anti-immunoglobulin antibodies; and, (4) quantitation of the bound antibodies in a fluorometer (FIAXTM). Using a purified myosin preparation as antigen, the assay was tested in experimental myocarditis of rabbits injected with cardiac proteins. Reproducibility was excellent, standard deviation of intra-assay variance being 7.86%, and inter-assay variance 9.45%. When compared with immunodiffusion, a complement fixation test with myosin and indirect immunofluorescence, the assay described proved superior since it allows simple monitoring of serum concentrations of antimyosin antibodies.

Animals↗

The platelet aggregation test in group B arbovirus infections.

A new serological method, the platelet aggregation (PA) test, was used to study Group B arbovirus infections, which are often associated with thrombocytopenia. The method is based on the interaction of antigen-antibody complexes with platelets. The PA test was nearly as good as the haemagglutination-inhibition (HI) test for epidemiological studies of tick-borne encephalitis (16 out of 18 HI positive sera) and was superior to the complement-fixation test which was positive in 10 out of 18 HI positive sera. The PA test could be used in the serological diagnosis of Group B arbovirus infection. The titres with the PA test were of the same magnitude as the HI titres, and about ten times higher than the CF titres. Two pairs of dengue haemorrhagic fever sera showed high initial PA titres. The role of immune complexes in the pathogenesis of haemorrhagic fevers is discussed.

Antigen-Antibody Reactions↗

Evidence of typhus infection in domestic animals in Egypt.

Previous work suggested that domestic animals could act as a reservoir of epidemic typhus. To test this hypothesis, sera from buffaloes, camels, donkeys, goats, pigs and sheep in different parts of Egypt were submitted to the complement-fixation test, using the common soluble typhus antigen. The highest percentage of positive results was obtained with camel and donkey sera and the positivity rate was higher towards the end of the year than in June and July. Animals from the Western Desert area were more frequently positive than those from other regions. Attempts to isolate rickettsiae by intraperitoneal injection of guinea-pigs resulted in some febrile reactions, but so far no rickettsiae have been isolated.

Animals↗