A microtiter agglutination test for anti-Pasteurella multocida antibodies in turkeys

A microtiter agglutination test (MTA) was developed for assaying anti-Pasteurella multocida antibodies in turkeys vaccinated with live avirulent Clemson University (CU) strain. Safranine-O was incorporated with the decapsulated P. multocida antigen and greaterly enhanced the visibility of the sedimented free antigen, which formed a compact red button on the bottom of the well. The advantages of the MTA test over the tube agglutination test were that: 1) less antigen and serum were required; 2) delineation of the end point was improved by staining the antigen with safranine-O; and 3) less labor was required.