Measurement of Actinomyces pyogenes specific antibodies in bovine blood samples by an enzyme-linked immunosorbent assay.

In the present investigation Actinomyces pyogenes specific antigens caused an antibody response in the host. This could be determined by two enzyme-linked immunosorbent assays (ELISA) using cell extracts and a haemolysin preparation as antigens. An increased antibody titre was detectable in the sera of cows vaccinated with culture supernatants of A. pyogenes and Peptococcus indolicus, in the sera of cows infected with live cells of A. pyogenes and P. indolicus, in the sera of cows suffering from 'summer mastitis', and in part of the sera of nonvaccinated, apparently healthy cows. However, the titre of the cows that were vaccinated with culture supernatants decreased 8-9 months after inoculation. Because of the wide variation in antibody titre the determination of A. pyogenes specific antibodies seems to be only of limited use for the control of this infection.