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PubMed1975

Use of different saprophytic acid-fast bacilli in complement-fixation test for kala-azar.

Complement-fixation tests for kala-azar using antigenic extracts from 4 different saprophytic acid fast bacilli were carried out. It was observed that all the 4 extracts gave positive reactions with sera from kala-azar patients. However, Myco. phlei gave best results and next comes Kedrowsky's bacilli. These two are different strains of the same organism, Myco. phlei. Myco. smegmatis also gave satisfactory results but Myco. butyricum gave weak and false negative reactions in some cases. Last two organisms are the different strains of the same Myco. smegmatis.

Antigens, Bacterial↗
PubMed1977

Demonstration of antibodies to soluble nuclear antigens by complement fixation test. An application of microtiter technique.

The complement fixation test utilizing the microtiter system was applied to study sera from patients with a variety of connective tissue diseases for the presence of antibodies to soluble nuclear antigens. A good correlation was found between microtiter complement fixation and hemagglutination for anti-RNP and anti-Sm antibodies. Anti-Ha antibodies were detected by complement fixation but not by hemagglutination. Different enzyme digestions of the soluble nuclear antigen prior to assay and use of a quantitative microcomplement fixation test were found to improve the analysis of sera with multiple antibodies.

Animals↗
PubMed1976

Studies on the origin of false positive reactions to the complement-fixation test for contagious bovine pleuropneumonia.

Serums of cattle free from contagious bovine pleuropneumonia (CBPP) were tested in complement fixation (CF) tests using 3 antigens; these were the standard antigen (SA) used to test to CBPP in Australia, an ethanol extract antigen (EA) also prepared from Mycoplasma mycoides subsp. mycoides (M. mycoides) and an antigen prepared from a Group 7 bovine mycoplasma isolated from arthritis (AA). The serums included 146 which fixed complement with SA. Eighty percent of these false-positive serums reacted with AA but not with EA; the other 20% were positive at low titre with EA but gave no reaction with AA. Attempts were made to produce false-positive serums experimentally by inoculating 3 Group 7 mycoplasmas and 2 Mycoplasma bovigenitalium strains into cattle. Serums from 3 of 9 cattle inoculated with strain L2917 (Group 7) reacted with SA but differed from the false-positive serums of field cattle by reacting with all 3 antigens. Tests with serums from cattle experimentally infected with CBPP gave similar titres with SA and EA, but the results with AA were mostly negative or less than 10% of the titres obtained with SA and EA. The results of CF tests on serums from the experimental cattle, after absorptions with suspensions of the mycoplasmas, showed that there was a one-way serological relationship between strain L2917 and M. mycoides and between this Group 7 strain and M. bovigenitalium. The CF tests with 3 antigens have assisted in demonstrating the false-positive nature of the reacting field serums encountered in the course of routine CF tests for CBPP in cattle in Australia.

Absorption↗
PubMed1988

New complement fixation test with peroxidase-labeled complement Clq for direct and quantitative determination of antibodies to herpes simplex virus.

An enzyme-labeled complement fixation (ELISA-CF) test for the direct and quantitative determination of complement fixing (CF) antibodies has been developed. This paper described the introduction of the ELISA-CF test that used peroxidase-labeled Clq component of complement to detect CF antibodies which had reacted with herpes simplex virus (HSV), as a virus model. Equal volumes of heat-inactivated serum and the peroxidase-labeled Clq (P*-Clq) were simultaneously added to wells of microplates which had been coated with HSV CF antigen or with cell control antigen. The enzymatic activities of P*-Clq bound to the immune complex were determined photometrically. The ELISA-CF test allows processing of serum specimens in a 3-hr operation, with procedural simplicity and increased specificity and sensitivity compared with the conventional CF test.

Antibodies, Viral↗
PubMed1969

[Immuno-Diffusion And Complement-Fixation Test In Paragonimiasis Of Cat]

In order to observe the complement fixation test and immuno-diffusion test of paragonimiasis, the sera taken at 10 days intervals up to 150 days from cats infected with Paragonimus westermani were examined by the above two immunological methods. The resultant findings were as follows: 1)The complement fixation test showed positive reaction 20 days after the infection with 20 metacercariae, and 40~50 days after the infection with 10 metacercariae. The highest titer was observed 110 days later following the acceleration at 80 days later. 2)In immuno-diffusion test, one are appeared 30 days after the infection with 20 metacercariae, but 60 days after the infection with 10 metacercariae. However, more than two arcs were observed since 70 days after infection. 3)A relatively wide band appeared by the antigens of Fresh worm material and Somatic material. But relatively clear precipitin lines were observed in the diffusion test with V.B.S. antigen, increasing to 3~4 arcs after 110days. 4)In general, complement fixation test showed earlier and higher sensitive reaction than immuno-diffusion test, and was considered to be more valuable method forr immunological diagnosis.

Journal Article↗
PubMed1983

The role of the differential complement fixation test, using rough and smooth brucella antigens, in the anamnestic test.

To assess the ability of the differential complement fixation test to distinguish vaccinal reactors from infected cattle, approximately 1,000 heifers were tested by the complement fixation test (CFT) using rough and smooth brucella antigens, before the injection of 45/20 vaccine and at 3 and 6 or 10 weeks after vaccination. Before vaccination 91.5% of heifers were negative to the rough antigen but 0.6% were positive with high titre (greater than or equal to 128). By 10 weeks after injection of 45/20 vaccine 97.6% of heifers were positive to the rough CF antigen, at greater than or equal to 8, a majority reaching greater than or equal to 128. Nineteen pre-vaccinal reactors to the standard CFT were killed and Brucella abortus was isolated from the tissues of 14. Twenty-six post-vaccinal reactors were killed and B. abortus was isolated from the tissues of 8. In the 22 B. abortus infected animals the differential CFT classified 9 correctly as infected, 5 incorrectly as vaccination reactions and 8 as inconclusive. The differential CF was ineffective in distinguishing titres resulting from vaccination with 45/20 vaccine from those due to infection.

Animals↗
PubMed1986

The relationship between the microtitration serum agglutination and complement fixation tests in bovine brucellosis serology.

The relationship between antibody titres in the microtitration serum agglutination test and the complement fixation test in bovine brucellosis is described. For low and high MSAT values there is good agreement between the 2 tests. This is not the case for MSAT values between 54 and 338 IU/ml. For practical reasons, results falling into this category cannot all be repeated. Repetitions are so structured that less than 4% of the tests need to be repeated. If the level of repetitions should show an increase above 4%, it is assumed that technical or human error has occurred.

Agglutination Tests↗
PubMed1976

[Use of indirect complement fixation test for studying foot and mouth disease virus].

The indirect complement-fixation test was used in experiments for the subtype differentiation, and with the agar gel diffusion and the serum neutralization test was studied the immunity in cattle that had already recovered from foot-and-mouth disease or were immunized against the disease. It was found that the indirect complement-fixation test is instrumental in the demonstration of the antigenic differences between the foot-and-mouth viruses. Comparative experiments have shown that the indirect test in this case is more expedient and of higher economic value than the direct CF reactions after Traub and Möhlmann and after Marucci. The assessment of the results of comparative investigations of sera carried out by the indirect complement-fixation test, the agar gel diffusion test, and the serum neutralization reaction revealed that the indirect reaction is a convenient, quick, and prompt method of work. Discussed is the sensitivity of the reaction and its advantages and its advantages in studies on a large scale on the immune status of animals immunized against F.M.D. or animals that have recovered from the disease.

Animals↗
PubMed1973

Equine infectious anemia: sensitivity of the agar-gel immunodiffusion test, and the direct and the indirect complement-fixation tests for the detection of antibodies in equine serum.

The comparative values of the direct, the indirect complement-fixation and the agar-gel immunodiffusion tests were assessed for the diagnosis of equine infectious anemia. Antibodies were detected on the agar-gel immunodiffusion test as early as 18 days post-inoculation in the serums of experimentally infected horses and were readily detectable in all the subsequent bleedings. Complement-fixing antibodies, demonstrable by the direct method, were detected commencing about the same time. However, these were not long-lasting and were replaced by the non-complement-fixing antibodies demonstrable by the indirect method; although both types of antibodies could be detected in some sera at the same time. In a herd of 55 horses, 28 were positive on the agar-gel immunodiffusion test, and among these 28 horses, 24 of them reacted on either the direct or indirect complement-fixation test or both. Thirteen horses that were negative on the three tests at the first sampling, reacted on the agar-gel immunodiffusion test 43 days later. Ten of these positive animals had direct type of complement-fixing antibodies; only one had the indirect; and two of them were negative on both tests. It appeared that the AGI test was a more reliable technique than either the direct or indirect complement-fixation tests, particularly when dealing with serums which contained small amounts of antibody. The sequential appearance of the two different types of complement-fixing activity might be used to determine the evolution of the disease on a herd basis.

Animals↗
PubMed1970

Direct complement fixation test with avian infectious bronchitis virus in chicken.

The direct complement fixation test was performed to follow the antibody response in chickens infected with avian infectious bronchitis virus. Concentrated allantoic fluid (4 units) was used as an antigen and allowed to react with serially diluted antiserum in the presence of two complete units of guinea-pig complement for 3 hr. at 4 degrees C. and (1/2) hr. at 37 degrees C. before the addition of sensitized cells. Serum was unheated and used either fresh or within one month of storage at -30 degrees C. Individual birds showed a rise and fall of complement-fixing antibody both after primary and secondary inoculations. The complement-fixing antibody was detected as early as the seventh day after primary inoculation. The highest complement fixation titre (1/32 to 1/64) was recorded from 14 to 21 days after inoculation with a subsequent gradual decline.The results of the direct complement fixation tests have been correlated with the serum neutralization test. The neutralizing antibodies usually appeared by the 14th day but were not detected at a significant titre until the 21st day after primary inoculation. Serum neutralizing antibodies were still present at high titres even after 7 weeks of infection but the complement-fixing antibodies had disappeared by that time.

Animals↗
PubMed1970

Serological diagnosis of human melioidosis with indirect hemagglutination and complement fixation tests.

An indirect hemagglutination (IHA) test and a complement fixation (CF) test were evaluated from test results on sera from 212 human melioidosis patients of which 119 were culturally proved cases. Significant antibody titers (IHA titers of 1:40 or greater and CF titers of 1:4 or greater) were demonstrated with either test in all except five patients. IHA and CF titers ranged as high as 1:20,480 and 1:1,024, respectively. Antibodies were usually demonstrated by both tests 1 week after onset of disease. Transient seronegative reactions during the course of disease were seen in sera of approximately 19% of the patients with either IHA and CF but rarely with both tests. High titers in either test were obtained by the third week of disease and reached maximum levels in 4 to 5 months. Titers usually were detectable for 9 or more months. Antibodies were detected by IHA and CF tests in 80 to 100% of the sera obtained at various time intervals from 9 months to 2 or more years after disease onset. Antibody persistence occurred in patients who had a short disease course, as well as in patients with prolonged, complicated infections. The IHA test had excellent specificity when evaluated with normal human sera and diverse antimicrobial sera from hyperimmunized rabbits and human patients. The CF antigen appeared to contain common antigens with some but not all types of Pseudomonas aeruginosa. The specificity of the CF antigen could be enhanced without appreciable effect on its sensitivity by use of a titer of 1:8 in lieu of 1:4 as a criterion for a significant reaction. Either test could be used advantageously for the laboratory diagnosis of melioidosis.

Animals↗