Antigenicity of Campylobacter jejuni flagella.

We studied the antigenicity of a wild-type flagellate and motile (F+M+) Campylobacter jejuni strain (81116) and two daughter mutants, one flagellate and immotile (F+M-) and one aflagellate and immotile (F-M-). By sodium dodecyl sulfate-polyacrylamide gel electrophoresis of acid-extracted surface proteins, a 63-kilodalton (kDa) band identified from sheared flagella as the flagellar protein was present in the F+M+ and F+M- strains but not in the F-M- strain. No other differences in protein profile among the three strains were noted. By Western blotting, serum from rabbits immunized with either the F+M+ or F-M- strain detected a 63-kDa protein in the F+M+ and F+M- strains but not in the F-M- strain. That the F-M- antiserum recognized the 63-kDa band suggests that small amounts of this protein or a cross-reacting antigen is present on the F-M- strain. By counterimmunoelectrophoresis of the acid-extracted preparations with immune sera, all three strains were found to share three major antigens, but a fourth antigen with a net positive charge was present only in the F+M+ and F+M- strains. Antisera to five C. jejuni and two Campylobacter fetus strains recognized the 63-kDa protein of purified F+M+ flagella in Western blots, demonstrating a common antigen is present, but enzyme-linked immunosorbent assay results suggest that the sharing of this antigen among Campylobacter strains is variable.