Phenotypic and antigenic variation of Mycoplasma gallisepticum vaccine strains

Phenotypic and antigenic variations among Mycoplasma gallisepticum vaccine F and Ts-11 strains were investigated by SDS-PAGE and serological methods (hemagglutination-inhibition and immunoblot assays). The SDS-PAGE system followed by densitometer analysis showed weak phenotypic variability between the strains, being the major difference close to the 75 kDa level where a prominent peptide band was detected only in the F vaccine strain. Polyclonal antibodies to the M. gallisepticum. antigens produced in chickens were used in serological tests for this antigenic variability study. There were strong cross-reactions between the strains and homologous/heterologous antibodies. The most evident characteristic was the specific response of the vaccine-type F polyclonal antiserum to the 75 kDa peptide band of the homologous strain.