AN ANTIGEN-CAPTURE ELISA FOR THE DETECTION OF MYCOPLASMA-BOVIS IN MILK

A monoclonal antibody which was largely specific to Mycoplasma bovis, cross-reacting only with M. agalactiae, was used in various antigen-ca pture ELISA formats for the detection of M. bovis in the milk of exper imentally infected ewes. The most sensitive application of the test wa s a combination of enrichment and capture by overnight incubation of e qual mixtures of sample and mycoplasma broth in antibody-coated microt itre wells. When used with milk-cell deposit samples, fractionated by centrifugation, it enables detection of at least 10(3) colony forming units of M. bovis per ml. The infection in experimentally infected ewe s became rapidly established resulting in the production of clinically abnormal milk from shrunken mammary glands. Post-mortem histopatholog ical examination of infected glands revealed changes in keeping with p reviously reported observations in M. bovis-infected bovine glands; di ffering only in the frequency of eosinophilic cytoplasmic granules in the intraluminal macrophages. These granules have been observed in ovi ne ureaplasma mastitis and may be a feature of mycoplasma mastitis in ewes.