A Macroglobulin (12 S) Agglutinin for Brucella Bovine Milk

Since milk from cattle infected with Brucella abortus may contain specific agglutinins for Brucella, milk is now widely used in several presumptive tests to detect brucellosis-suspicious herds. In the brucellosis eradication program, some herds have been encountered in which the milk of a single animal reacted in high dilution to the Ring Test (13), yet blood serum from these animals did not give significant reactions to the tube agglutination test (1) and repeated attempts failed to isolate Brucella from the milk of these individual cows. Studies to determine the nature and cause of this phenomenon resulted in the isolation of a macroglobulin (12 S) agglutinin for Brucella from milk and the development of a procedure which appears to differentiate this agglutinin from those observed concurrently with the isolation of Brucella abortus . The 12 S Brucella agglutinating component has been isolated from two nonvaccinated cows (No. 2002 and 2159) of the type described above, which were obtained from herds with a history of no Brucella infection during the previous 4 yr.