Genetic properties of RM 98, an R plasmid of Salmonella which determines sensitivity to the phage IKe.

An R plasmid of Salmonella, RM98, which determines sensitivity ot the phage IKe (IKeS) and confers resistance to ampicillin (Ap), streptomycin (Sm) and tetracycline (Tc) was studied for its genetic properties in Salmonella typhimurium and Escherichia coli, Transduction of RM98 by P22 in Salmonella yielded transductants of which some had acquired all the recognizable markers (Ap, Sm, Tc, IKeS and resistance transfer factor or RTF) associated with RM98. This transduction pattern resembles the P22 transduction pattern of IKe-specific R plasmids: R45, R46, R48, R205 and N3. Preliminary genetic analysis of RM98 has indicated that the determinants of IKeS and RTF are closely linked and the determinants of Ap and Sm are closer to RTF-IKeS than they are to Tc.