Host Ranges of R Factors

Abstract

SUMMARY All R factors so far described can be transmitted to Escherichia coli. F-like R factors are transmissible to the Proteus group but not to the Pseudomonadaceae. Among, fi − R factors, I-like plasmids are not transferable to Proteus although they mediate conjugation, allowing transfer of other plasmids to this group. They are not transmissible to the Pseudomonadaceae. P-group plasmids are transmissible to both taxa. Plasmids of groups N and W are transmissible to Proteus (transfer to Pseudomonas was not tested because of lack of suitable markers).