Purification and partial characterization of type 3 fimbriae from Salmonella typhimurium var. copenhagen.

Aggregative thin fimbriae from a pigeon pathogen, Salmonella typhimurium var. copenhagen (STMVC) Mö 8 were isolated and purified. These fimbriae remained associated with the cells even after attempts to separate them from blended cells by centrifugation. After purification, fimbriae and little cell fractions were polymerized in formic acid and then analyzed by SDS-PAGE. This pretreatment resulted in the appearance of a main protein band of 17 kDa. The N-terminal amino acid sequence of 19 residues of purified 17 kDa protein showed considerable homology with the N-terminal sequence of thin fimbriae of S. enteritidis. Native fimbriae on whole cells were specifically labelled with immune serum raised to the purified fimbriae. This immune serum also reacted with the denatured 17 kDa protein in Western blots. The polyclonal immune serum did not cross-react with the type-1 fimbriae produced by STMVC.