抄録
Many urinary isolates which belong to the Enterobacteriaceae and bear multiple drug resistance were shown to harbor transmissible resistance factors (R factors). The levels of resistance were almost uniform in every strain investigated. The resistance markers were usually transferred as a unit. Frequency of transfer varied from host to host even when the same recipient strain was employed. However, no remarkable differences were observed in successive transfers of R factors between substrains of Escherichia coli K-12. The role of R factors in urinary tract infection is discussed.
