APPLICATION OF A MONOCLONAL ANTIBODY-BASED ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR DETECTION OF AN INFLAMMATORY RESPONSE ANTIGEN IN SUBCLINICAL MASTITIC MILK SAMPLES

A monoclonal antibody to a 23.5-kDa bovine inflammatory antigen present in high levels in mastitic milk has been used in an antigen-capture enzyme-linked immunosorbent assay (ELISA) to screen milk samples from herds of cattle for subclinical mastitis. The results from 20 herds with a total of 2,612 quarter samples are presented. Good correlation was observed between the ELISA level and the milk cell count (MCC). The results demonstrated an average of 5% false negatives (1.8% associated with isolates of Staphylococcus aureus and/or Streptococcus spp.) and 7.7% false positives for each herd in relation to mastitic (> 400,000 cells per ml) or nonmastitic (< 400,000 cells per ml) MCCs.