[Construction of Hfr strains in "Salmonella montevideo" (author's transl)]

Lac+ variants of Salmonella montevideo were recovered from mating with an Escherichia coli strain harbouring the thermosensitive sex-factor Ft114-lac+. The properties of these variants suggest that this F' factor behaves identically in Salmonella and Escherichia. From these variants, it is possible to select mutants in which lac expression is stable at high temperature (42 degrees C) and it was proved that they behave as Hfr's. Twelve independently isolated Hfr's were similar with respect to both point of origin and sequence of markers transferred. These results suggest that our strain of S. montevideo carries an F-factor affinity site near met C gene.