[Avian mycoplasmosis: Comparative study of the plate agglutination test, haemagglutination inhibition test and metabolic inhibition test for detection of antibody against Mycoplasma gallisepticum].

This study was performed with the use of the MG/S6 strain of Mycoplasma gallisepticum, reference sera, sera from vaccinated chickens (given at inactivated vaccine) and sera from infected turkeys in the field. Titres of antibody detected were well correlated for the three tests. However, the plate agglutination test (PAT) allowed the earliest detection, and metabolic inhibition test (MIT) was as sensitive and specific as the haemagglutination inhibition test (HIT). MIT allowed a good repeatability of results, and discriminated very well between positive and negative sera. Serological studies with MIT using a constant dilution of sera gave results comparable with titration by MIT, with a valuable saving of time and material. PAT was found to be one of the best techniques for mass serological screening. Results with MIT and HIT confirmed the PAT results, but MIT was more easily interpreted, particularly with sera taken during the late phase of antibody decrease.