Drug Resistance of Enteric Bacteria V. High Frequency of Transduction of R Factors with Bacteriophage Epsilon

Abstract

Kameda, Mitsuo (Gunma University, Maebashi, Japan), Kenji Harada, Mitsue Suzuki, and Susumu Mitsuhashi . Drug resistance of enteric bacteria. V. High frequency of transduction of R factors with bacteriophage epsilon. J. Bacteriol. 90: 1174–1181. 1965.—In the transduction of R factors with phage ε 15 , a lysate capable of transducing the markers for (TC) or (CM.SM.SA) resistance at high frequency was obtained. The transducing agent is a defective element called ε 15 dR 23 which lacks certain functions of phage ε 15 . After lysogenization with normal ε 15 phage and ultraviolet (UV) induction, strains carrying the ε 15 dR 23 element produce lysates which have a high frequency of transduction (HFT) on group E 1 Salmonella . Lytic lysates prepared on phage ε 15 sensitive strain with the ε 15 dR 23 element have a low frequency of transduction (LFT). Lytic growth of phage ε 34 on an ε 15 dR 23 strain or UV induction of an ε 34 lysogenic strain containing ε 15 dR 23 results in LFT lysates on group E 2 Salmonella . On UV induction, group E 2 Salmonella (ε 15 lysogens) with the ε 15 dR 23 element give lysates which are HFT on group E 1 Salmonella but are LFT when tested on group E 2 Salmonella . In all instances, the production of drug-resistant transductants requires infection of the cell with only a single ε 15 dR 23 element. It appears that the resistance region of the R factor has replaced that portion of phage genome which is essential for vegetative replication and superinfection immunity. The ε 15 dR 23 element does not contain the genetic determinants of the R factor responsible for transmissibility, inhibition of F mating, and interference between two R factors.