Differentiation of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cell proteins.

The protein patterns of whole cells of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum were studied by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protein patterns of the 16 strains of E. rhusiopathiae and E. tonsillarum studied, including the type strains of these two species, resembled each other, except that there were 71-, 41-, 34-, and 26-kDa proteins in the E. rhusiopathiae pattern and 74-, 44-, 36-, and 25-kDa proteins in the E. tonsillarum pattern. This observation indicates that there is some phenotypic heterogeneity in the genus Erysipelothrix. In addition, the protein patterns of E. rhusiopathiae serotype reference strains representing serotypes 1 through 23 and type N were compared. The protein patterns of serotype 1a, 1b, 2, 4, 5, 6, 8, 9, 11, 12, 15, 16, 19, and 21 and type N strains were similar to the pattern of the type strain of E. rhusiopathiae (strain ATCC 19414). Conversely, the protein patterns of serotype 3, 7, 10, 14, and 20 strains were very similar to the pattern of the type strain of E. tonsillarum (strain ATCC 43339). An atypical pattern was observed in serotype 13, 17, 18, 22, and 23 strains. These results suggest that this method may be used as an aid in studying the taxonomy of these bacteria.