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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↗
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↗
PubMed1975

A specific complement-fixation test for human hepatitis a employing CR326 virus antigen. Diagnosis and epidemiology.

A specific diagnostic complement-fixation test for hepatitis A antibody in human serum was described employing livers of marmosets infected with CR326 strain human hepatitis A virus. Persons with hepatitis A, but not hepatitis B, developed hepatitis A CF antibody shortly after the onset of illness and this persisted thereafter. Good agreement was noted in the development of CF and neutralizing antibodies in hepatitis A cases. Hepatitis A was shown to occur in a person with hepatitis B antigenemia and hepatitis B occurred in persons with hepatitis A antibody. Most persons with hepatitis A who were tested, but none of those with hepatitis B, developed increased anticomplementary activity in their sera at the time of onset of illness. At least one patient with hepatitis A developed antibody against normal liver that persisted. The possible inplications of this in relation to pathogenesis and to non-specific diagnostic tests in hepatitis were discussed. A limited epidemiologic study of a family outbreak of hepatitis in Costa Rica and of a group of young adults in our epidemic country acquire their infections at an early age and are immune thereafter; persons in areas of relatively low incidence may proceed into adulthood without experience with hepatitis A. The CF test should provide an excellent tool for diagnosis and for epidemiologic investigation of hepatitis A and should be of considerable value to detect hepatitis A virus in attempts to propagate the virus in cell culture.

Adolescent↗
PubMed1976

A comparison between the haemagglutination inhibition and complement fixation tests for Newcastle disease.

The value of the complement fixation (CF) test as a means of assessing the immune response of fowls to Newcastle disease virus was examined using several strains of virus. A close degree of correlation was found between the CF test and the simpler haemagglutination-inhibition (HI) test. Like the HI test, the CF test only gave an indication of the immune status and was not a direct measurement of immunity.

Animals↗
PubMed1977

Complement fixation test of Nebraska calf diarrhea virus with calf serum.

A complement fixation (CF) test for neonatal calf diarrhea has been developed with Nebraska calf diarrhea virus (NCDV) as antigen. The CF antigenicity of NCDV appeared in BK cell cultures for the first time 3 days after inoculation. Usually, the unconcentrated BK cell culture fluid infected with NCDV possessed poor CF antigenicity. The fluid concentrated by ultracentrifugation and ultrafiltration and with polyethylene glycol 6000 revealed a high-titered CF antigenicity to antiserum against NCDV. The antigen was not sensitive to lipid solvents, but was relatively resistant to heating. It was recognized that the concentrated fluid of cell culture infected with NCDV was available as antigen in the CF test for the serological demonstration of infection with a calf reovirus-like agent. The wide prevalence of diarrhea among Japanese calves with the calf reovirus-like agent was revealed from the results of CF and neutralization tests of NCDV.

Animals↗
PubMed1975

A rapid slide flocculation test for the diagnosis of American trypanosomiasis using Trypanosoma cruzi fragments preserved by lyophilization. Comparison with hemagglutination, immunofluorescence, and complement fixation tests.

A slide flocculation test for Chagas' disease is described, which uses a lyophilized, stable antigen obtained by formalin and ultrasonic treatment of culture forms of Trypanosoma cruzi. The test was compared with other tests for the serodiagnosis of American trypanosomiasis and showed a high sensitivity, positive results being obtained in every case of acute or chronic Chagas' disease. In sera from blood donors and from normal individuals with negative T. cruzi antigen complement fixation tests a specificity of 96% was found. False positive flocculation tests were seen, especially in cases of South American blastomycosis and in a few cases of acute toxoplasmosis. Since it is easy and quick to perform, the slide flocculation test can be recommended as a screening procedure, especially for blood banks.

Bacterial Infections↗
PubMed1975

An improved quantitative micro-complement fixation test.

The technical procedures for a simple quantitative micro-complement (C) fixation test are described. Major advantages of the present technique compared with the previously described method are: a) a simple measurement of the residual hemolytic activity of C by counting the radioactivity released from 51Cr-labeled sensitized sheep erythrocytes (51Cr-EA); b) an increased sensitivity of the test, brought about by the use of a relatively small number of 51CR-EA per reaction volume; and c) an increased specificity of the test, achieved by maintaining a constant amount of C available for the specific antigen--antibody reaction.

Adenoviridae↗
PubMed1979

The complement fixation test and African trypanosomiasis: I. Experimental infection and re-infection in cattle before and after treatment.

The complement fixation test was applied to assess antibody responses in cattle infected with T. brucei, T. congolense, and T. vivax which had been treated and re-infected. After the first infection, the specificity of the results was low in T. congolense, fair in T. brucei, and high in T. vivax infected animals. After re-infection with the same trypanosoma species as used for previous infections, the specificity of CF results was high in all cases. After a foregoing T. vivax infection, specific titres of T. congolense and to a lesser degree of T. brucei infections were frequently masked by residual T. vivax titres. After treatment of trypanosoma-infected cattle the fasted drop of CF antibody titres occurred in T. congolense cases, followed by T. brucei infections. T. vivax titres persisted over prolonged periods.

Animals↗
PubMed1975

[Study of the outcome of pregnancy in sheep with positive serologic reactions to toxoplasmosis according to the complement fixation test].

Studied were five flocks of 240 sheep each. It was found that prior to impregnation the positive complement-fixation test (c. f. test) reagents varied from 16 to 61 per cent with titers ranging from 1:50 to 1:10. Abortions, however, were established only in two of the flocks consisting of young sheep, aged 3 and 4 years, at the first or second lambing. The abortions took place in the fourth month of pregnancy. In one of these flocks having 43 per cent positive reagents there were 40 per cent returns, and 28 of the ewes miscarried, 12 of them being positive for toxoplasmosis. In the second flock there were 61 per cent positive reagents, and 9 of the ewes miscarried, 5 of them being positive for toxoplasmosis. In the remaining three flocks consisting of 5-year-old sheep there were no abortions. The ewes that miscarried and were positive for toxoplasmosis showed a rise in their serum titers: from 1:40 on the 15th day after the abortion to 1:80 on the 30th day. It is believed that in these sheep the abortions are not due to toxoplasmosis, and in sheep flocks with a high percent of positive toxoplasmosis reagnets there may not be abortions.

Abortion, Veterinary↗
PubMed1978

Anticomplementarity in complement-fixation test with soluble antigens of the spotted fever group rickettsiae.

Anticomplementarity occurring in the complement-fixation (CF) test with soluble antigens of rickettsiae of the spotted fever (SF) group is caused by interaction of soluble antigens with guinea pig sera serving as the source of complement. The serum factor responsible for anticomplementarity is thermostable and cannot be removed by treatment of guinea pig serum with CO2 or nitrogen. An adverse effect of such serum was also observed upon its mixing with other guinea pig sera lacking anticomplementarity properties. An anticomplementarity factor present in the soluble rickettsial antigens was sensitive to treatment with potassium periodate.

Animals↗
PubMed1991

Evaluation of enzyme-linked immunosorbent assay in comparison with complement fixation test for the diagnosis of subclinical paratuberculosis in cattle.

An enzyme-linked immunosorbent assay (ELISA) was evaluated and compared in parallel with the standard complement fixation test (CFT) for the diagnosis of bovine subclinical paratuberculosis. Bovine sera preabsorbed with the mixture of Mycobacterium phlei and kaolin suspension were assayed for antibody activities to the crude protoplasmic antigen of Mycobacterium paratuberculosis in the ELISA. ELISA antibody titer was expressed as ELISA antibody index (EAI) value: EAI = (At-An)/(Ap-An), where At, Ap and An are the absorbance values of a 1:200 dilution of unknown test sera, a 1:400 dilution of positive control serum, and a 1:200 dilution of negative control serum. An EAI of 0.6 or greater was established as a reasonable cutoff point for a positive antibody titer by ELISA. Of the 156 sera from cattle with subclinical M. paratuberculosis-infection, 106 (67.9%) were positive by ELISA and 41 (26.3%) by CFT. Of the 3,880 sera from cattle in the herds which had no history or evidence of paratuberculosis, 3,875 (99.9%) were negative by ELISA, and 3,787 (97.6%) by CFT. Positive ELISA titers were detectable 1 to 5 months earlier than positive CFT titers in experimentally infected cattle, and 7 to 10 months earlier in naturally infected cattle. These results indicate that the ELISA should replace the CFT as the routine test of choice for the diagnosis of bovine paratuberculosis.

Animals↗
PubMed1992

Evaluation of five commercial tests: complement fixation, microparticle agglutination, indirect immunofluorescence, enzyme-linked immunosorbent assay and latex agglutination, in comparison to immunoblotting for Mycoplasma pneumoniae serology.

A panel of 68 serum specimens from 41 subjects exhibiting various immunological patterns to Mycoplasma pneumoniae as determined by detection of a 180 kDa protein in immunoblotting was used to compare five commercially available tests based on different methods: complement fixation test (CFT), microparticle agglutination (MAG), indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (Elisa), and latex agglutination (LA). The tests were performed according to the manufacturers' instructions. For the determination of immunity to M pneumoniae, the five tests were in good accordance with immunoblotting: sensitivity was 100% for all the five assays, specificity ranged from 95.6% (MAG) to 82.6% (Elisa) and overall agreement ranged from 98.2% (MAG) to 92.8% (Elisa). The comparisons of antibody rates obtained by the four quantitative tests (CFT, MAG, IFA, Elisa) showed correlation coefficients ranging from 0.87 (CFT-IFA) to 0.67 (CFT-Elisa). Six significant antibody rises demonstrated by immunoblotting patterns were detected by all the tests but Elisa in one case. As a whole, the commercial assays gave satisfactory results for routine determination of immune status to M pneumoniae: CFT was the cheapest test and MAG and LA were the easiest to perform.

Adolescent↗