Molecular cloning of the fimbrial subunit gene from a benign type B isolate ofBacteroides nodosus

Abstract

The fimbrial subunit gene from the benign type B Bacteroides nodosus isolate AC/6 was cloned into the SphI site of the multicopy vector plasmid pUC19. Five Escherichia coli recombinants that were positive in a colony immunoassay were shown, by Western transfer analysis, to produce an immunologically cross-reacting protein of identical molecular size to fimbrial subunits prepared from B. nodosus AC/6. Restriction endonuclease analysis showed that 4 of the recombinant plasmids carried a 6.7 kb SphI fragment. Recloning experiments showed that the fimbrial subunit gene was located within a 2.5 kb EcoRI-SphI fragment and that there was a PstI site located within the structural gene or its regulatory region. These recombinant clones will prove useful for the construction of a multivalent recombinant vaccine for the control of ovine footrot.