[Cloning and expression of the genetic determinants encoding for the serological variants of the adhesive factor K 88 carried by enterotoxinogenic Escherichia coli strains of porcine origin].

The existence of homologous sequences on plasmids carried by 3 enterotoxinogenic strains of Escherichia coli of porcine origin, and encoding for adhesive factors of different antigenic specificities: K 88 ab, K 88 ac, K 88 ad; has been demonstrated by DNA-DNA hybridization. The use as probe of a DNA fragment carrying a piece of structural genes of the adhesive factor K 88 ab taken out of a recombinant plasmid expressing this factor, has allowed us to localize the genetic determinants which encode for the adhesive factors K 88 ac and K 88 ad. Cloned in the plasmid pBR 322, these determinants have allowed us to obtain the expression, by the host bacteria of the corresponding adhesive factors.