[Mapping the fucidin resistance marker in S. typhimurium and a study of the properties of its transductants].

The fusidic resistance marker in S. typhimurium is contransduced in 95% of cases by means of P 22 phage with the streptomycin resistance marker. The transfer of the fusidic acid resistance gene doesn't lead to any significant alterations in the tranductants' properties (morphology, antigenic structure, growth rate, biochemical activity, sensitivity to other antibiotics). The fusidic acid resistant mutants and transductants studied displayed a significantly decreased virulence to albino mice. The rate of this decrease, however, doesn't correspond to the degree of transductants' resistance. Virulent variants are also possible.