Plasmids of incompatibility group P code for the capacity to propagate bacteriophage IKe

Abstract

Seven of 8 plasmids of incompatibility group P coded for the capacity to propagate bacteriophage IKe in Escherichia coli. Six of the seven plasmids allowed propagation of IKe by 1 bacterial host (RG172) but not by another (RG176); the other plasmid allowed IKe propagation by both hosts. IKe propagation by a number of E. coli K-12 strains was quite variable. IKeh, an extended host range mutant of IKe, was found to plaque specifically on N+ and P+ strains.