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PubMed1972

Equine infectious anemia: preparation of a liquid antigen extract for the agar-gel immunodiffusion and complement-fixation tests.

An agar-gel immunodiffusion test recommended for the diagnosis of equine infectious anemia was evaluated. Our preliminary observations confirmed those of Coggins concerning the mechanism of the test and the results obtained. Furthermore, emphasis was put on the difficulties encountered in the production of spleen antigens with an optimum amount of reactivity. Acetone-ether extraction procedures for the preparation of a liquid antigen extract are described. This type of antigen was reactive in the complement-fixation test in 1:8 or greater dilution and it is proposed to use the complement-fixation test in assessing and standardizing the liquid antigen extract activity to be used in the immunodiffusion test. This antigen can also be concentrated or diluted, if required, to meet the reactivity of a standard antigen used in the test.

Animals↗
PubMed1977

[Radial complement fixation test and convex lens method for the determination of antibodies in tissues].

The radial complement fixation test has to be made in forms in 1.4% layer of agar in physiological saline in a Petri dish. These forms have to be of the same thickness as the reaction itself, usually about 1 mm. In the first layer, it is recommended to mix antigen with complement and sheep erythrocytes in agarose and this mixture is to be poured over the tissue fragments examined. Following the primary incubation (at room temperature overnight), another mixture of haemolysin in agarose is poured over the first layer in form of optical convex lenses. The haemolytic phase is performed at room temperature, too. The complement is titrated together with the optimal amount of antigen and a drop of positive serum is placed in the well just in the centre of the first layer. In this way an optimal dilution of complement is detected, which is capable of producing a full hemolysis outside the zone of the positive serum diffused during the first, primary incubation period, whereas the zone itself remains untouched with the haemolytic activity of complement.

Animals↗
PubMed1977

Comparison of coccidioidin and spherulin in complement fixation tests for coccidioidomycosis.

Coccidioidin, an extract from the saprophytic mycelial form of Coccidioides immitis, has been a very useful antigen preparation in serological tests for coccidioidomycosis. Its sensitivity has been very good for detecting most types of clinical disease, but tests with coccidioidin have been negative for 40% or more of patients with chronic pulmonary disease, the clinical entity which must be differentiated from other cavitary, nodular, or fibrotic pulmonary disease, e.g., tuberculosis and cancer. The specificity of coccidioidin has also been good although it results in positive tests for an average of 16% among patients with noncoccidioidal mycoses. Recently spherulin, an extract from the parasitic endosporulating spherule form of C. immitis, was reported to be more sensitive than coccidioidin in concurrent complement fixation tests with sera from selected cases. We have compared coccidioidin and spherulin in concurrent complement fixation tests with 614 sera submitted routinely for coccidioidal serology and with 159 selected sera from patients with noncoccidioidal mycoses. Among the former, spherulin was positive with 25% and coccidioidin with 23%, and correlation of titer scores was highly significant. Statistical analysis revealed no significant differences with respect to frequency of positive specimens, titer scores, or diagnosis for current coccidioidomycosis. The results with sera from noncoccidioidal mycoses revealed marked differences. Coccidioidin was positive with 20%, and spherulin was positive with 48%. The titer scores with spherulin were consistently and significantly higher, and there was no correlation for results with the two antigens. Thus, coccidioidin and spherulin were equally sensitive, but spherulin was considerably less specific.

Antigens, Fungal↗
PubMed1976

Improving the specificity and yield of the contagious bovine pleuropneumonia complement fixation test antigen.

Several methods for increasing yield and specificity of the contagious bovine pleuropneumonia complement fixation test antigen which is derived from Mycoplasma mycoides subsp mycoides, strain V5, were examined. Changes in culture conditions that increased the cell mass per unit volume of culture did not result in comparable increase in antigen yield. Sixteen to 60-day-old cultures yielded more boiled cell antigen than younger cultures. Some antigen in young cultures appeared to be masked, probably by galactan. The yield of antigen extracted from boiled cells with ethonol was as much for two to eight-day-old cultures as for older cultures. The ethanol extract antigen was less reactive with false positive bovine sera than standard boiled antigen while reactivity with anti Mycoplasma mycoides sera was similar to that of standard antigen. Adsorbed gamma globulin was not detected in either boiled or ethanol extract antigen. The data suggest that several complement fixing antigens were present in antigens derived from older cultures.

Animals↗
PubMed1979

Rotavirus antibody assays on monkey sera: a comparison of enzyme immunoassay with neutralization and complement-fixation tests.

An enzyme immunoassay (EIA) for the detection of rotaviral antibodies was developed, using a purified, cell culture-grown SA 11 viral antigen and alkaline phosphatase as an enzyme label. This technique was evaluated by comparative testing with tube neutralization and complement-fixation assays on a collection of simian sera. There was close correlation between positive and negative results obtained by EIA and by neutralization. The EIA was as easy to perform as complement fixation testing, but showed greater sensitivity and fewer nonspecific reactions. Thus, EIA was shown to be a very suitable test for routine detection of rotaviral antibodies in serum. Results of neutralization tests suggested that the monkeys (mostly rhesus macaques) in the present study were infected with viruses varying in their antigenic relatedness to SA 11 virus and to a British isolate of calf rotavirus.

Animals↗
PubMed1983

Cross-reactivity of Haemophilus somnus antibody in agglutination and complement fixation tests and in the enzyme-linked immunosorbent assay.

The specificity and sensitivity of agglutination, complement fixation, and enzyme-linked immunosorbent assay (ELISA) procedures in the detection of antibodies to Haemophilus somnus was investigated. H. somnus rabbit immune sera were found to agglutinate Pasteurella multocida, Staphylococcus aureus, and Haemophilus agni and, in some instances, also Pasteurella haemolytica, Salmonella dublin, Streptococcus agalactiae, and Corynebacterium pyogenes. In complement fixation tests with saline extracts as antigens, only H. agni reacted with H. somnus antisera to any significant degree. In ELISA tests with sonicated or heat-extracted antigens, cross-reactions were seen with the two Pasteurella spp. and with H. agni. When whole cells and saline extracts were used as antigens in ELISAs, only H. agni showed any cross-reactivity. The greatest specificity in distinguishing homologous from heterologous reactions was achieved by ELISA with saline extracts as antigens. Escherichia coli and Brucella abortus antigens failed to react with H. somnus antibody in any of the tests. A rabbit serum containing antibody to bovine type isolates of P. multocida, P. haemolytica, S. aureus, S. agalactiae, S. dublin, C. pyogenes, and E. coli gave no positive reaction in ELISA tests with saline extract of H. somnus as antigen. It is concluded that such saline extract, which appears to consist largely of H. somnus common antigen, has the potential of being a useful diagnostic reagent in the study by ELISA of antibody response to H. somnus.

Agglutination Tests↗
PubMed1976

Detection of type-specific antibody to herpes simplex virus type 1 and 2 in human sera by complement-fixation tests.

Type-specific antigens for herpes simplex virus type 1 and 2 were prepared by rigorous absorption of cell extracts with heterotypic immune sera. Type-specificity was demonstrated by immunodiffusion and complement-fixation tests against immune sera prepared in rabbits. Specific type 1 complement-fixing reactivity was detected in eleven of fifteen sera from Roman Catholic nuns and in two convalescent sera from patients with recurrent herpes labialis; these sera had been previously shown to contain neutralising and complement-fixing antibody to herpes simplex virus. Three of the non-reacting sera contained low or absent levels of type-common complement-fixing reactivity and other contained no type-specific neutralising antibody. With the exception of three "acute" sera, specific type 2 complement-fixing reactivity was detected in every convalescent or interim serum obtained from patients with a virologically-proven history of type 2 herpes virus infection. It is suggested that complement-fixation testing using these absorbed type-specific antigens preparations may provide a convenient and rapid method for the identification of type-specific antibody in human sera.

Antibodies, Viral↗
PubMed1975

Mechanization of a micro complement fixation test for the serodiagnosis of human toxoplasmosis.

A description is given of a mechanized micro complement-fixation test for the serodiagnosis of human toxoplasmosis. Besides a reduction in the quantity of reagents by using a microplate a considerable advantage of the test is the mechanization of actually all steps. Examination of large numbers of sera can be realized in a relatively short period of time. In order to test the sensitivity of the micro CF test comparative studies were carried out with the macro CF test and the immunofluorescence (IF) test on 549 human sera. The micro CF test proved to be more sensitive than the macro CF test. The results obtained with the micro CF test were in better agreement with the IF test than those obtained with the macro CF test.

Autoanalysis↗
PubMed1982

[An ELISA test for detection of maedi-visna antibodies. Comparative study with gel immunodiffusion and complement-fixation test].

An indirect microELISA test was performed for detection of maedi-visna antibodies in ovine and caprine species. The antigen consisted in viral particles, highly purified by successive ultracentrifugations. By comparative testing of 934 sera in ELISA and gel immunodiffusion, we found a good correlation between these two tests, and moreover, ELISA revealed another 11.3% of positive samples. The precocity of this ELISA was shown by experimental infection of sheep with different strains of maedi-visna: positive sera were detected 7 weeks post-infection, instead 4-5 months with gel immunodiffusion. The complement fixation test was compared with gel immunodiffusion and was found the less sensitive. This ELISA test appeared to be satisfactory, and may be used for early diagnosis of maedi-visna infection.

Animals↗
PubMed1994

Comparison of a complement fixation test, a gel diffusion test and two absorbed and unabsorbed ELISAs for the diagnosis of paratuberculosis in sheep.

A complement fixation test for paratuberculosis, a gel diffusion test and two enzyme-linked immunosorbent assays (ELISA) were evaluated using sera from Mycobacterium paratuberculosis infected and non-infected sheep. Gross pathology and histopathology were used as parameters of infection. The two ELISAs, one of which is commercially available for testing cattle, were used before and after sera had been absorbed with a soluble sonicate of Mycobacterium phlei. Differences between the various tests and between ELISAs before and after absorption were non-significant (P > 0.05) in non-infected sheep or in animals with gross or histopathological lesions. The specificity of all the tests was at least 97%. Sensitivity in histopathologically positive sheep was at least 98%. Sheep from infected flocks but without histopathological lesions showed serological results which were poorly correlated between the various tests.

Animals↗
PubMed1982

Sensitivity and specificity of two microtitre complement fixation tests for the diagnosis of Brucella ovis infection in rams.

An investigation was made into microtitre complement fixation test (CFT) procedures suitable for the serological diagnosis of naturally occurring Brucella ovis infection in rams. A procedure similar to the Australian standard procedure for bovine brucellosis was unsatisfactory when applied to sheep. Modification of the procedure by use of an initial serum and anticomplementary control dilution of 1:8 and increasing complement fixation time to 60 minutes at 37 degrees C, greatly improved the efficiency of the test. A sensitivity of 100% was recorded for 59 serums from known infected rams and a specificity of 99.9% for 1593 serums from rams known or believed to be free of infection. Some aspects of applying CF tests to sheep serums are discussed.

Animals↗
PubMed1987

Antibody response in patients infected with Campylobacter jejuni/coli assayed with a complement fixation test and a DIGELISA method.

Two methods for the detection of antibodies against Campylobacter jejuni/coli, a complement fixation test (CFT) and a DIG-ELISA method, were tested against a panel of single sera from 36 coproculture positive patients. Twenty-five were positive in CFT compared to 31 in the other system. Twenty-three out of 25 CFT positive sera were positive in the ELISA method. Seven sera were positive only for IgA antibodies thus negative in the CFT. CFT may be useful for the detection of IgG/IgM antibodies against C. jejuni/coli. However, serum IgA may be a valuable marker for infections with C. jejuni/coli. Methods such as DIG-ELISA may identify such cases.

Antibodies, Bacterial↗