Comparison of outer-membrane fractions of Serpulina (Treponema) hyodysenteriae.

Sarkosyl-insoluble fractions (outer-membrane proteins) and endoflagella (EF) fractions of Serpulina hyodysenteriae serotypes 1-7 were examined for protein differences using SDS-PAGE. Both the outer-membrane proteins (OMP) and endoflagella were also examined for antigenicity using porcine sera from acutely infected and convalescent swine. Seven major staining proteins were resolved in outer-membrane enriched fractions ranging in molecular weight between 42 and 32 kDa. A comparison of purified EF to OMP from serotype 1 and 2 isolates of Serpulina hyodysenteriae demonstrated that six of the seven OMP were actually EF. Sera from swine with acute swine dysentery identified only a portion of the proteins from both preparations. In contrast, immune sera from convalescent swine identified all the proteins in the OMP and EF preparations as well as an additional 16 kDa carbohydrate antigen.