Studies of the genetic expression of 31A finbriae by two bovine septicaemic Escherichia coli strains

Using transposon tnphoA, classical bacterial genetic assays, SDS-PAGE and Western blot of superficial proteins, we have studied the expression of the 31A fimbriae of two bovine wild-type septicaemic Escherichia coli strains. The genes responsible for encoding colonization factor 31A were located in both the plasmid (strain BZ2468) and the chromosome (strain BZ43). The results obtained using HeLa cell cultures led us to believe that the BZ43 strain could have another colonization factor besides 31A, since one mutatnt, which did not express fiinbriae, was still able to adhere to HeLa cells.