Epidemiology and chromosomal location of genes encoding multiresistance in Salmonella dublin

Multiresistant Salmonella dublin strains isolated between 1971 to 1984 were investigated for their genetic and physical properties. It turned out that the multiresistance of the 1971 to 1973 isolates was plasmid-encoded. In the following years, however, the plasmid profiles of the strains were indistinguishable from sensitive isolates and the genes encoding the multiresistance were located on the Salmonella chromosome.