Six strains of Mycoplasma arthritidis isolated from different host tissues were examined for differences in their proteins and antigens by using one- and two-dimensional electrophoretic techniques as well as immunoblotting. One-dimensional electrophoresis revealed differences in concentrations of individual bands, but not differences in the overall banding pattern. By two-dimensional electrophoretic analysis, 25 proteins were identified as strain-variable whereas the majority of protein spots was strain-constant (about 195 after IEF-2D-PAGE and 145 after NEPHGE-2D-PAGE). Immunoblot analysis using an antiserum against the type-strain of Mycoplasma arthritidis (PG 6) revealed size-heterogeneity of antigens of all six strains. An epitopic relationship between these size-variant antigens could be demonstrated by using monospecific antibodies produced against some of these antigens of Mycoplasma arthritidis. Furthermore, we describe a highly variable antigen of Mycoplasma arthritidis similar to that shown previously in Mycoplasma pulmonis.
Animals Antigenic Variation