[The development of drug resistance in Salmonella strains isolated from animals in Sweden 1955-65 and 1973-4(author's transl)].

134 salmonella strains, isolated from animals in 1955-65 were compared to 133 salmonella strains isolated in 1973-74, with regard to their drug resistance and the frequentcy of R-factors. No significant changes were observed during the reference period. Salmonella typhi-murium in comparison with other serotypes harboured a significantly larger number of resistant strains. Of the recently isolated resistant strains that were searched for R-factors, about half the number were carriers. All strains were sensitive to chloramphenicole and neomycin.