Quantitation of bovine immunoglobulin G2 by a competitive fluorescence immunoassay.

Bovine immunoglobulin G2 (IgG2) was quantitated by fluoroimmunoassay (FIA) based on competition with fluorescein-conjugated IgG2 for Sepharose-bound anti-IgG2 antibodies. The optimal range was 0.1 to 1 microgram IgG2. The FIA was compared with the single radial immunodiffusion (SRD) test. Both methods gave comparable means and standard errors for IgG2 in serum. The FIA method was 30 times more sensitive.

A comparative study of ELISA and other methods for the detection of Brucella antibodies in bovine sera.

Enzyme-linked immunosorbent assay (ELISA), using beta-galactosidase and a fluorigenic substrate, was used for the detection of antibodies to Brucella abortus in bovine sera. Among 677 animals from 9 brucellosis-free herds, none reacted in the ELISA. Among 785 animals from 23 brucellosis-infected herds, 336 were positive in ELISA, 229 in the slow agglutination test (SAT), 185 in the complement fixation test (CFT), and 165 in the Rose-Bengal test (RBT). Experimental infections were conducted with two B. abortus strains. Al slaughter on day 101, after intraconjunctival infection of heifers with B. abortus strain 19 organisms, 3 animals were positive in the SAT, 3 in the CFT, 4 in the RBT and 11 in the ELISA, and Brucella organisms could be cultivated from 10 animals; among these, 2 scored positive in the SAT, 3 in the CFT, 3 in the RBT and 8 in the ELISA test. Seventeen heifers were infected with organisms of B. abortus strain 2308. On day 101, 11 heifers were found to be carriers, all of which yielded positive results in the CFT, RBT and ELISA tests, but not in the SAT.

[Immunofluorescence tests for the detection of antibodies against Corynebacterium pyogenes and streptococci in blood serum and vaginal mucus of cattle]. / Immunofluoreszenzuntersuchungen zum Nachweis von Antikörpern gegen Corynebacterium pyogenes und Streptokokken im Blutserum und Vaginalschleim von Rindern.

Bacteriological tests were applied to cattle with endometritis and vaginitis. Included were cervical mucus samples and immunofluorescence tests to detect in that mucus as well as in blood serum antibody to Corynebacterium pyogenes and Streptococcus haemolyticus. The results pointed at intensive contact of the animals with the above pathogens and to their frequent occurrence in cervical mucus of cattle afflicted with endometritis and vaginitis. They also supported the assumption of localised antibody formation in the sexual organs or female cattle.

Studies about the adjuvant activity of saponin fractions in foot and mouth disease vaccine. III. Comparison of the irritant, adjuvant and hemolytic activities of six commercial saponins and their hemolytic fractions obtained by chromatography on sephadex G 100.

12 experimental vaccines were prepared to compare the irritant and adjuvant activity in cattle of 6 commercial saponin preparations and their hemolytic fractions. It is still not known if a single substance is responsible for the irritant, adjuvant and hemolytic activities of the saponin preparations. The quantities of saponin added were standardised on the base of a constant hemolytic activity rather than on a weight of powder per dose of vaccine base. A FMD vaccine was used to reveal the adjuvant activity. It was concluded that the irritation is related to the hemolytic activity and not to the weight of powder. Irritation is slightly reduced when a toxic effect appears. The adjuvant activity was higher for untreated saponin preparations with high hemolytic activity used at low dose and for one of the chromatographic saponin fractions. The adjuvant activity is reduced when toxic effect appear. Toxicity of less hemolytic saponins used at high dose is removed by chromatography. Highly hemolytic saponins used at low dose become toxic after chromatographic treatment.