[Ability of conjugated plasmids of serotyped E. coli to inhibit genetic transfer of depressed FLAC and PAP22-4 plasmids].

A group of conjugation plasmids identified in the cells of wild strains of E. coli isolated from the people and animals were examined. The majority of plasmids showed the ability to inhibit Flac plasmid genetic transfer functions. However, some of them differed in the levels of inhibitory activity. Similar experiments with derepressed F-like pAP22-4 plasmid demonstrated that it is marked by a less ability (as compared with Flac plasmid) to be inhibited by different plasmids. This circumstance is possibly related to the specificity of the genetic regulation of plasmid transfer functions.