[Mobilization of plasmid determinants of Yersinia pestis using the plasmid pKA7]

Yersinia pestis plasmids having inserted Tn-movable elements and determining pesticinogenicity, Ca2+-dependence, production of mice toxin and fraction I have been mobilized for conjugal transfer into Y. pestis, Y. pseudotuberculosis or E. coli cells by plasmid pKA7. Plasmid determinants have been transferred with the frequencies 10-4-10-7 per donor cell. The plasmid DNA of high molecular mass has been identified in transconjugant cells. Plasmid mobilization in Yersinia pestis is supposed to be due to cointegrate formation of yersinia plasmids with R-plasmids.