ENZYME-LINKED IMMUNOSORBENT-ASSAY FOR DETECTION OF MILK IMMUNOGLOBULINS TO LEUKOCIDIN TOXIN OF STAPHYLOCOCCUS-AUREUS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 46  (8) , 1728-1732
Abstract
Leukocidin toxin from a bovine strain of S. aureus was partially purified by ion exchange chromatography. An ELISA was developed to quantitatre antibodies specific for leukocidin in bovine milk. This was used to assay quarter samples from 88 cows in a S. aureus-infected herd for antibody levels to the toxin. Milk samples from 65 cows with S. aureus infections in at least 1 quarter produced a mean optical density of 1.054, whereas milk samples from 23 cows that were free of bacteria on cultural examination had a mean optical density of 0.584. There was a significant difference (P < 0.001) in milk anti-leukocidin levels between these 2 groups. Evaluation of serum samples from 40 of these cows indicated that the milk anti-leukocidin concentrations were reflective of systemic anti-leukocidin values. The capability of 57 milk samples to neutralize the cytolytic effect of minimal amounts of leukocidin on bovine peripheral blood neutrophils was examined. Good correlation existed between the ELISA antibody concentration and toxin-neutralizing capability of individual milk samples.