Enzyme immunoassay for detecting Brucella antibodies in cow's milk.

An enzyme immunoassay (EIA) was developed for detecting Brucella antibodies in milk of cows infected with Brucella abortus. The enzyme immunoassay using heat-killed cells of B. abortus strain 19 was of comparable sensitivity to the Brucella ring test in detecting antibodies in milk of a reference positive control cow experimentally infected with B. abortus strain 2308 and in milk of 16 naturally infected cows from which B. abortus was isolated. No detectable enzyme immunoassay reactions were present in milk of 11 noninfected controls. The enzyme immunoassay is a procedure which can be readily automated so that screening tests for brucellosis could be conducted at a reference laboratory where uniform conditions can be maintained.