Abstract: The isolation and characterization of the promoter regions of the genes which code for the pilinic subunits fim2, fim3 and fimx of Bordetella pertussis, are described, as well as the construction of vectors containing the regions, and microorganisms transformed by the vectors.The promoter regions, or nucleotide fragments thereof, are particularly useful for the regulable or non-regulable expression of genes which code for a protein of interest in a strain of Bordetella. The transformed Bordetella strains are particularly suitable for the development of an effective anti-pertussis vaccine.