Mobilization of transduced tetracycline resistance by the delta transfer factor in Salmonella typhimurium and S. typhi.

Abstract

IT has been shown that transferable drug resistance factors (R-factors) are composed of two basically independent entities1–5: (1) genetic determinants for drug resistance; (2) transfer factors, which are linked to the determinants to form complexes which are transferred from donor to recipient cells by conjugation. In the absence of a transfer factor, resistance determinants are transmitted only in a linear fashion. In the absence of resistance determinants, the transfer factors have no resistance to transfer.