Enzyme-linked immunosorbent assay for Streptococcus agalactiae antibodies in bovine milk
Logan, E.F.; Meneely, D.J.; Mackie, D.P.
Veterinary Record 110(11): 247-249
1982
ISSN/ISBN: 0042-4900 PMID: 7043885 Document Number: 194538
An ELISA technique was developed by using whole bacterial cells as antigen. Microtitre wells were coated overnight at room temperature with a 1:64 dilution of antigen in 0.05M carbonate-bicarbonate buffer at pH 9.6. After washing, milk whey samples diluted 1:40 were added, incubated overnight and again washed. After incubation with rabbit antibovine serum, bound antibody was detected with alkaline phosphatase-conjugated sheep anti-rabbit serum. Antibodies in individual quarters of cows in a severely infected dairy herd were measured. A high proportion of cows had specific antibody to Streptococcus agalactiae in one or more quarters. Using ELISA in association with electronic cell count and bacterial isolation, it was possible to identify latent and subclinical carriers of infection.