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PubMed1981

Comparison of a microtitration complement-fixation test and a tube latex agglutination test for diagnosis of Mycoplasma hyopneumoniae swine pneumonia.

Comparison of a tube latex agglutination (LA) test and a microtitration complement-fixation (CF) test for the diagnosis of Mycoplasma hyopneumoniae swine pneumonia was done. In a group of 107 pigs from Iowa, Texas, and California (survey A), correlation of data on microscopic pulmonary changes with the LA and CF titers indicated the LA test might be a better indicator of microscopic lesions than the CF test. In another field study involving lungs from 50 pigs from various herds (survey B), both LA and CF test results predicted gross lesions at a 0.01 significance level, using chi-square analysis. Data from 3 Nebraska swine herds (survey C) indicated good correlation of gross and microscopic pulmonic lesions with CF and LA test results in 2 of the 3 herds. In the 3rd herd, results of the CF test failed to agree with either gross and microscopic pulmonic lesions or culture results, whereas LA test results closely correlated with these variables. Chi-square analysis at 0.5 significance level of 106 pigs from 5 Iowa specific-pathogen-free herds (survey D) indicated a correlation of CF and LA test results with the microscopic pulmonic changes of penmates.

Animals↗
PubMed1984

Comparison of complement fixation test and enzyme-linked immunosorbent assay for detection of early infection with Mycoplasma hyopneumoniae.

The relative merits of the complement-fixation test (CF) and enzyme-linked immunosorbent assay (ELISA) for the detection of the early antibody response to Mycoplasma hyopneumoniae were evaluated. Discriminant analysis, a statistical procedure, was used to avoid difficulties associated with variation in background color and nonspecific reactions obtained with ELISA with different sera. Specific-pathogen-free pigs were exposed by contact to other specific-pathogen-free pigs which had been inoculated with M hyopneumoniae intratracheally (experiment A) or intranasally (experiment B) 18 to 21 days previously. Sera were collected from each pig before contact exposure and once a week until necropsy. Antibodies were detected by CF at postexposure (PE) week 3 in animals in experiment A (6 of 18) and at PE week 5 in experiment B (3 of 12). The ELISA antibodies were detected at 2 weeks after beginning of contact exposure in experiments A (4 of 18) and B (1 of 12). Examination of pooled data for experiments A and B indicated that ELISA was substantially (P less than 0.05) more sensitive for detection of antibodies than was the CF test at 3 to 5 weeks after contact exposure began. At PE weeks 6 and 7, both tests were similarly effective in detecting M hyopneumoniae antibodies.

Animals↗
PubMed1968

A new whole-scolex complement-fixation test for hydatid disease.

The sensitivity of indirect agglutination tests for the diagnosis of human hydatid disease, although high, is not sufficient. Furthermore, the general use of hydatid fluid as antigen is responsible for some false positive reactions. Scolex extracts have been shown to increase specificity, but less attention has been paid to whole-scolex antigens. The author describes a new whole-scolex complement-fixation test that, like other scolex tests, is more specific than tests using fluid antigen. Its sensitivity is at least equal to that of the hydatid fluid latex-agglutination test, and is higher than that of the fluorescent-antibody, the scolex extract latex, and the hydatid fluid complement-fixation tests.The new test is also of interest since particulate antigens are uncommon, compared with soluble antigens, in complement-fixation techniques.

Antigens↗
PubMed1980

[Complement fixation test act in the diagnosis of mucosal disease-virus diarrhea in cattle].

Experiments were made to obtain a highly active antigen for the complement-fixation test, using purification and concentration with methyl alcohol in a cell culture suspension of the causative agent of mucous disease-virus diarrhea. It was established that the CF test was sufficiently rapid and specific in the diagnosis of the disease in cattle. It proved instrumental in detecting complement-fixing antibodies in diseased and survived cattle, in calves with a latent infection and in cows with abortions.

Animals↗
PubMed1984

A complement fixation test for visceral leishmaniasis using homologous parasite antigen II. Results in an endemic area in Kenya.

Further studies of the complement fixation test using homologous parasite antigen in an endemic area for visceral leishmaniasis have showed that 82% of individuals with proven visceral leishmaniasis were positive initially whilst 92% were positive at some stage during their illness. Titres fell slowly following effective treatment and anticomplementary activity, confined to confirmed visceral leishmaniasis, was usually lost during treatment. Individuals with alternative causes of hepatosplenomegaly from the same population were negative apart from those with a presumptive diagnosis of visceral leishmaniasis but without parasitological confirmation. Less than 1% of people in the same endemic area without visceral leishmaniasis were positive, suggesting that preliminary serodiagnostic investigation would limit the need for invasive investigation under field conditions.

Adolescent↗
PubMedDate not supplied

Development of a microtitration complement-fixation test for diagnosis of Mycoplasma gallisepticum infection in chickens.

A direct microtitration complement-fixation (CF) test was developed for diagnosis of Mycoplasma gallisepticum infection in chickens. CF titers were demonstrated three weeks postinoculation in chickens inoculated intratracheally with M. gallisepticum. The direct microtitration CF test appeared comparable to the hemagglutination-inhibition test in sensitivity and specificity. Addition of fresh chicken serum to lyophilized guinea pig complement (GPC') was not necessary to enhance fixaton of GPC' by the immune complex of M. gallisepticum CF antigen and chicken MG antibodies. Attempts to use this CF test in detecting antibodies against Mycoplasma synoviae in chickens failed because the M. synoviae CF antigen was often anticomplementary and nonspecific.

Agglutination Tests↗
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↗
PubMed1985

The use of a single complement fixation test technique in bovine brucellosis, Johne's disease, dourine, equine piroplasmosis and Q fever serology.

The same techniques may be used in the complement fixation test (CFT) for the serological diagnosis of bovine brucellosis, Johne's disease (paratuberculosis), dourine, equine piroplasmosis and Q fever (caused by Coxiella burnetii). The reproducibility of results is excellent, falling for the most part within the twofold range and never exceeding the fourfold range. Agreement with other laboratories is excellent (i.e. within twofold) in the case of brucellosis and equine piroplasmosis antibody titres. A good correlation between the occurrence of the disease and serological reactions is found on circumstantial evidence in the cases of dourine, Johne's disease and Q fever. A standard unitage system is used to report the antibody titres found in all the tests. To simplify laboratory protocols, laboratories required to employ the CFT for the diagnosis of these diseases are advised to use a single proven technique in all the tests. Problems experienced with transient false-positive Johne's disease antibody titres in cattle following on tuberculin (bovine and avian) testing make it advisable to take specimens for the Johne's disease test prior to performing the tuberculin tests.

Animals↗
PubMed1984

Preparation, assessment and preservation of antigen from Brucella abortus strain 45/20 for use in the rough antigen complement fixation test.

Two methods of extraction were used to prepare antigens from Brucella abortus rough strain 45/20. The antigens were assessed for use in the complement fixation test. A suitable antigen was prepared using the saline extraction method of Miller et al. (1976) and used extensively in CF tests. Four methods of preservation were compared; -20 degrees C, -196 degrees C, 0.5% phenol at 4 degrees C, and lyophilisation. The antigen could be stored at -20 degrees C or -196 degrees C for up to 2 years.

Animals↗
PubMed1996

Serological diagnosis of ovine enzootic abortion by comparative inclusion immunofluorescence assay, recombinant lipopolysaccharide enzyme-linked immunosorbent assay, and complement fixation test.

Since the 1950s, serological diagnosis of ovine enzootic abortion (OEA), caused by strains of Chlamydia psittaci, has been based mainly on the complement fixation test (CFT), which is neither particularly sensitive nor specific since antibodies to other chlamydial and enterobacterial pathogens may be detected. In this study. a recombinant enzyme-linked immunosorbent assay (rELISA) (medac, Hamburg, Germany), based on a unique chlamydial genus-specific epitope of Chlamydia trachomatis L2 lipopolysaccharide, was evaluated for sensitivity and specificity as a primary screening assay for OEA by comparison with the CFT. A comparative inclusion immunofluorescence assay (IFA), in which antibody titers to C. psittaci and Chlamydia pecorum were examined, was used as the reference test for 573 serum samples from four flocks. Reactivity to C. pecorum was measured since inapparent intestinal infections by C. pecorum are believed to be common in British flocks. In detecting positive sera from an abortion-affected flock, in which a C. pecorum infection was also suggested by IFA, the rELISA outperformed the CFT with significant evidence for increased sensitivity (P = 0.003). In two flocks in which C. pecorum infections alone were suggested by IFA, the rELISA and CFT were prone to detect low levels of false-positive results, but the values were not significant. The rELISA provided results in one flock in which sera that were anticomplementary could not be resolved by the CFT. In another flock in which abortion had not occurred but infection by both chlamydial species was suspected, no significant difference was found between the sensitivities of the rELISA and CFT. The rELISA could not differentiate ovine C. psittaci and C. pecorum infections but was shown to be a more sensitive primary screening test for OEA than was the CFT, particularly where abortion had occurred and even when antibodies due to additional inapparent infection(s) by C. pecorum were present.

Abortion, Veterinary↗
PubMed1988

Application of the single radial complement fixation test for serodiagnosis of influenza, respiratory syncytial, mumps, adeno type 3, and herpes simplex type 1 virus infections.

A stabilized modification of the single radial complement fixation (SRCF) test in gel was developed for detecting various virus antibodies. The principle of the test is based on the use of a single-stage procedure with an agarose plate containing virus antigens and antibody-coated erythrocytes, and thin plastic film coated with complement. By filling the wells in the agar plate with a 1:4 diluted heat-inactivated sera and covering the agar surface with a complement film, a zone of unlysed cells surrounded by a hemolytic area appears after incubation overnight at 4 degrees C and then for 1-2 h at 37 degrees C, depending on the antibody titers. The SRCF antibody titer is calculated numerically from the square of the diameter of the unlysed cell zone. The stability of reagents could be significantly improved using thin complement film and several stabilizers. When this test was used for serodiagnosis of influenza, respiratory syncytial (RS), mumps, adeno virus type 3 and herpes simplex type 1 virus infections (using a total of 400 sera), excellent correlations were demonstrated for antibody titers between conventional complement fixation (CF) and SRCF titers. Furthermore, the expression of antibody titer as an SRCF unit with consecutive value, produced results sensitive to fluctuations in the antibody titers. The simplicity of the procedure, stability of the reagents, and excellent correlation with the conventional CF test might make this a useful test for routine serodiagnosis and seroepidemiological survey of various virus infections.

Adenovirus Infections, Human↗
PubMed1982

[Barbital buffer in tablets as a solvent for complement fixation test (CFT)].

The purpose of this paper was to develop a tableting technology of barbital buffer as a standard diluent easy in use for complement fixation test (CFT). As starting point, barbital (veronal) buffer after Alton et al. [1] was assumed. Among 4 solubilizers polyvinyl pyrrolidone (PVP 10 000) was chosen, which provided a good solubility of the barbital in distilled water at 20 degrees C and it affected favourably the complement activity (C'). PVP 10 000 added to the components of barbital buffer at an amount of 0.275 per 10 tablets, in the form of solution for granulation, provided the required physical properties of the tablets. As compared with the barbital buffer after Alton et al. [1], the tablets produced affected favourably C' activity, decreased the range of spontaneous haemocyte lysis, and they did not effect CFT titers of two anti-Brucella abortus standard sera as well as 77 sera of cattle infected with brucellosis under natural conditions. The described physical and biological properties of the barbital buffer tablets with PVP addition indicate their usability as diluent for CFT. A standard diluent used in the form of tablets in all Poland's laboratories should provide a better reproducibility of CFT results in diagnostic examinations towards brucellosis as well as other infectious diseases in men and animals.

Animals↗
PubMed1996

Enzyme-linked immunosorbent assay, complement fixation test and immunoelectroprecipitation test in the diagnosis of Mycoplasma pneumoniae infections--comparative analysis.

Agreement of the results of determining antibodies against M. pneumoniae was evaluated by ELISA, complement fixation test (CFT) and immunoelectroprecipitation test (IEPT) in serum samples from 685 persons including 571 patients with respiratory tract infections and 114 clinically healthy subjects. Assuming the CF test to be the reference test, a very high correlation exceeding 0.95 was found, on the basis of the calculated correlation coefficient, between the results of the CF and IEP tests and the CFT and ELISA for all immunoglobulin classes. The highest sensitivity (92.3%) was displayed by the ELISA in relation to the CF test when determining mycoplasmal antibodies of Ig M and Ig A+G+M classes and a slightly lower sensitivity by the IEPT and ELISA when determining Ig G (83% and 82.1%, respectively). The lowest sensitivity was displayed by the ELISA when determining mycoplasmal antibodies of the Ig A class (53.4%). The specificity of both tests was high and exceeded 92%. The highest agreement of CFT and ELISA was obtained when detecting mycoplasmal antibodies in a diagnostically significant titre in the M and A+G+M immunoglobulin classes (> 92%) while the lowest agreement, although statistically significant, was obtained when detecting Ig A antibodies (74.7%).

Adolescent↗
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↗
PubMedDate not supplied

Comparative evaluation of the Premier enzyme immunoassay, micro-immunodiffusion and complement fixation tests for the detection of Histoplasma capsulatum var. capsulatum antibodies.

A total of 178 sera, including 68 from proven cases of histoplasmosis (65 positive for the presence of Histoplasma capsulatum var. capsulatum antibodies and three positive for antigen), 93 from patients with suspected histoplasmosis but with no laboratory evidence of H. capsulatum var. capsulatum infection, 14 from humans with heterologous fungal and non-fungal infections and three from normal individuals, were tested for IgG H. capsulatum antibodies and M or M and H precipitins by enzyme immunoassay (EIA) (Meridian Diagnostics, Cincinnati, OH, USA) and microimmunodiffusion (MID) respectively. Sixty-three of the 68 histoplasmosis case sera demonstrated IgG antibody, and 65 of 68 demonstrated the presence of specific precipitins in the MID test. Nine positive case sera, when tested with the Laboratory Branch complement fixation (LBCF) test, reacted positively to whole yeast and histoplasmin antigens (titres 1:8 to 1:512). Three histoplasmosis case sera repeatedly tested negative for IgG, specific precipitins and complement-fixing antibodies, whereas they were positive for Histoplasma antigen. Eighteen of 95 sera from patients without evidence of histoplasmosis demonstrated IgG antibody in the EIA only. Among these positive sera, three out of three cases of aspergillosis and three out of five cases of blastomycosis were confirmed. Sera from HIV-infected and healthy individuals did not show IgG or M and/or H antibodies to H. capsulatum. Ninety-three sera were negative by both EIA and MID. The EIA for IgG was less sensitive (97%) than MID (100%). The specificity of EIA and MID was 84% and 100% respectively.

Antibodies, Fungal↗