Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Complement Fixation Tests”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed2001

Brucella abortus RB51 and hot saline extract from Brucella ovis as antigens in a complement fixation test used To detect sheep vaccinated with Brucella abortus RB51.

The efficacy of Brucella abortus RB51 and hot saline extract (HSE) from Brucella ovis as antigens in complement fixation (CF) tests was comparatively evaluated in detecting immune responses of sheep vaccinated with B. abortus strain RB51. For this study, four 5-month-old sheep were vaccinated subcutaneously with 5 x 10(9) CFU of RB51, and two sheep received saline. Serum samples collected at different times after vaccination were tested for the presence of antibodies to RB51 by a CF test with RB51 as antigen, previously deprived of anticomplementary activity, and with HSE antigen, which already used as the official antigen to detect B. ovis-infected sheep. The results showed that vaccinated sheep developed antibodies which reacted weakly against HSE antigen and these antibodies were detectable for 30 days after vaccination. However, antibodies to RB51 could be detected for a longer period after vaccination by using homologous RB51 antigen in CF tests. In fact, high titers were still present at 110 days postvaccination with RB51 antigen. Sera from sheep naturally infected with B. ovis also reacted to RB51 but gave lower titers than those detected by HSE antigen. As expected, all sera from RB51-vaccinated sheep remained negative when tested with standard S-type Brucella standard antigens.

Animals↗
PubMed1979

Comparison of 4 serological tests--complement fixation, neutralization, fluorescent antibody to membrane antigen and immune adherence hemagglutination--for assay of antibody to varicella-zoster (V-Z) virus.

Four tests for antibody to varicella-zoster (V-Z) virus were compared; these were tests of complement fixation (CF), neutralization (NT), fluorescent antibody to membrane antigen (FAMA) and immune adherence hemagglutination (IAHA). Fifty-two sera from patients with varicella and zoster and from recipients of live varicella vaccine were examined by the 4 tests. The CF test was least sensitive, but the antibody titers by the NT, FAMA and IAHA tests were roughly comparable. The IAHA test was the simplest and fastest to perform, and appeared suitable for routine serological assay to V-Z virus. The correlation between the IAHA antibody titer and susceptibility of individuals to clinical varicella was investigated retrospectively using sera obtained during 2 outbreaks of varicella in an institution for children, where all the unvaccinated children had developed varicella symptoms. Most of the 25 pre-exposure sera from unvaccinated children examined by the IAHA test had tiers of less than 1:2. In contrast, all the 23 sera from vaccinated children who did not develop varicella had detectable antibody titers of 1:2 to 1:64. These results indicate that the IAHA titer reflects the susceptibility or resistance of individuals to clinical varicella.

Antibodies, Viral↗
PubMed1994

Screening for antibody to Chlamydia pneumoniae by the complement fixation test.

We performed a retrospective survey for antibody to Chlamydia pneumoniae, by the microimmunofluorescence (MIF) test, on 120 sera that were previously determined to be positive for antibody to ornithosis antigen by the complement fixation (CF) test. The panel of sera comprised 40 paired acute and convalescent sera, and 40 single samples, from 80 patients. Of these patients, 60% were considered to be serologically positive for C. pneumoniae, based on the antibody titers of IgG, IgM, or both. There was no association between the CF titer to ornithosis antigen and the respective IgG or IgM MIF antibody titers. We propose that, in those laboratories routinely using the CF test, sera found to be positive for ornithosis antigen should be further tested by the MIF in order to clarify, both from an epidemiologic and clinical perspective, whether these patients are also serologically positive for C. pneumoniae.

Adolescent↗
PubMed1986

Serological diagnosis of influenza A infections in the horse by enzyme immunoassay. Comparison with the complement fixation test.

An enzyme immunoassay (EIA) using horseradish peroxidase and a type-specific antigen is described for the detection and quantitation of anti-influenza antibodies in the horse. Compared with the complement fixation (CF) test (using the same antigen), EIA proved to be superior with respect to sensitivity and reliability. The internal variation of EIA was low and thus small titres in EIA can be considered of diagnostic significance. However, no strict correlation with CF was observed. The use of an immunoconjugate against equine IgM in parallel with IgG would certainly improve the sensitivity of the test, especially in early stages of infection.

Animals↗
PubMed1997

Serological diagnosis of chlamydial abortion in sheep and goats: comparison of the complement fixation test and an enzyme-linked immunosorbent assay employing solubilised proteins as antigen.

A new ELISA for antibodies against chlamydial abortion of ewes which uses detergent solubilised proteins (dsp) of Chlamydia psittaci as antigen (Anderson, I.E., Herring, A.J., Jones, G.E., Low, J.C., Greig, A., 1995. Development and evaluation of an indirect ELISA to detect antibodies to abortion strains of Chlamydia psittaci in sheep sera. Vet. Microbiol., 43, pp. 1-12] was compared with the complement fixation test (CFT) in screening 1000 ovine and caprine sera obtained from selected flocks/herds ('flocks') and submitted to a veterinary diagnostic laboratory. Fifteen of the 17 'flocks' had a history of abortion while the remaining two did not and were classified as 'negative flocks'. Infection with Chlamydia was confirmed during the study period in five 'flocks' using direct immunofluorescence and the modified Ziehl Neelsen stain on pathological material. The dspELISA and CFT identified 37 and 45 positive sera on 158 samples tested from these 'flocks'. Chlamydia antibodies were not detected in one of the two negative flocks, in two other flocks where the cause of abortion was undetermined and in three flocks in which the causes of abortion were diagnosed as Listeriosis and/or Salmonellosis. One of the 'negative flocks' yielded two positive reactors by CFT and five by dspELISA, suggesting infection with a cross-reactive subtype of C. pecorum. Of the five 'flocks' in which a definitive diagnosis from pathological material was not possible, four were positive by both serological tests, suggesting that the abortions were due to Chlamydia. The fifth flock, though negative by dspELISA and marginally positive in two samples by CFT, had experienced confirmed chlamydial abortions in previous lambing seasons, but culling and tetracycline treatment have prevented further abortions in the study period. Overall, the proportions of samples positive by CFT and dspELISA were similar (9.1% and 8.8%). These studies confirmed the value of the dspELISA as a screening test for chlamydial abortion. Furthermore, the dspELISA compared to the CFT is easier to perform, does not require reagent titration at each testing and uses automated assessment of results.

Abortion, Veterinary↗