Application of the indirect enzyme immunoassay for the detection of antibodies against Erysipelothrix rhusiopathiae.

Sera from swine and rats experimentally infected with Erysipelothrix rhusiopathiae and field sera from swine were investigated for antibodies against E. rhusiopathiae using the microtiter enzyme immunoassay (EIA) and, for comparison, the growth test (GT) and the agglutination test (AT). In principle there was a good correspondence between the results of EIA and those of the two other methods, but EIA and GT were more sensitive than AT. On the basis of the evaluation pattern of GT and AT on swine sera, EIA titers of 1/320 were considered as "chronic erysipelas titers". Compared with GT and AT, the EIA has some advantages: it is not influenced by contamination of the test sera, it takes only a few hours and using the microtiter system it is easy and economical to perform.

Antigenic cross-reactions between Mycoplasma arthritidis and rat tissues.

An antigenic relationship between Mycoplasma arthritidis and rat tissues could be demonstrated using the enzyme-immune assay and the agar gel double diffusion test. Cross-reactions were observed with joint homogenates as well as with muscle, lung, liver, kidney, spleen and brain tissue from rats. In addition, antibodies against joint homogenate were found in the sera of rats infected with M. arthritidis ISR 1 using the indirect hemagglutination test. The significance of common antigens between M. arthritidis and rat tissues for the pathogenesis of the M. arthritidis polyarthritis in rats is discussed.

Studies of polyarthritis caused by Mycoplasma arthritidis in rats. II. Serological investigation of rats experimentally infected with M. arthritidis ISR 1.

In sera of rats which developed severe polyarthritis after infection with 10(9) CFU of Mycoplasma arthritidis ISR 1, antibodies against M. arthritidis could be detected by the complement fixation test (CFT), enzyme immune assay (EIA), indirect hemagglutination (IHA), and metabolic inhibition test (MIT). Peak titers (CFT - 1:4096, EIA - 1:2560, IHA - 1:640 and MIT - 1:64) were reached between 2 and 12 weeks after infection. The antibodies persisted for at least 9 months, but started to decrease gradually 5 to 7 months after infection. No antibodies against M. arthritidis could be detected in the growth inhibition test. Immune complexes were found 4 days after infection. They decreased rapidly during the first two months after infection after which they increased again. At no time, rheumatoid factors could be detected. Rats which had recovered from the polyarthritis induced by intravenous injection of M. arthritidis ISR 1 were resistant to a subsequent infection.

Serological investigation of horse sera for antibodies against mycoplasmas and acholeplasmas.

Sera from horses with respiratory disease (RD) have been investigated using the complement fixation test, indirect hemagglutination test, enzyme immune assay, and the metabolic inhibition test, and sera from mares after abortion, using the complement fixation test, indirect hemagglutination test and enzyme immune assay, for antibodies against Mycoplasma equirhinis, M subdolum, M. equigenitalium, M. pulmonis, M. felis, Acholeplasma laidlawii, A. hippikon and A. equifetale. Antibodies were found against all mycoplasma and acholeplasma species tested, more often against acholeplasmas. The antibody pattern was quite similar for horses with RD and for mares after abortion. The results of the four serological tests performed showed only a limited correlation and the percentage of sera with antibodies detected by the four tests used differed widely.