Abstract
The electrophoretic patterns of cell proteins in polyacrylamide gels were used for the study of several taxonomic problems in the Mycoplasmatales. The patterns of five Mycoplasma hominis strains showed marked differences that corresponded with their known serological and nucleic acid heterogeneity. The patterns of three M. mycoides var. mycoides strains isolated in different countries were essentially identical. The electrophoretic patterns of several caprine strains resembled those of M. mycoides var. mycoides, supporting their classification as M. mycoides var. capri. Strain B3, a swine isolate, accordingly was tentatively identified as M. mycoides var. capri. The bovine mastitis strain M. agalactiae var. bovis possessed a pattern basically similar to that of the goat mastitis strain M. agalactiae, supporting the inclusion of both strains in one species. Three M. pulmonis strains isolated from rats or tissue cultures showed nearly identical patterns. The pattern of the toxigenic M. neurolyticum (Sabin A) strain resembled but was not identical with that of the nontoxigenic PG28 strain. The avian Mycoplasma species, M. gallisepticum, M. meleagridis, M. synoviae, M. gallinarum, and M. iners showed easily distinguishable and specific patterns, supporting their present classification in different species. Several improvements in the electrophoretic technique are described, and its advantages and limitations as a taxonomic tool are discussed.