Transduction of tetracycline resistance in Staphylococcus epidermidis

Fourteen Staphylococcus epidermidis strains were biotyped according to the scheme of Baird-Parker and tested for their sensitivities to S. epidermidis typing phages. Tetracycline-susceptible strains were tested for the capacity to be transduced to resistance. Five strains, all of biotype 1, were lysed by one or more phages. Five of eight biotype 1 strains were transduced to tetracycline resistance with rates of 10(-8) to 10(-5). Three strains of other biotypes were not transduced, nor was PS 73, an unusual coagulase-negative strain. The transducing phage phi367 was isolated from the lysogenic tetracycline-resistant donor strain. The phage morphologically resembles serological group B S. aureus phages. Restriction and modification were indicated from the efficiency of plating on phage-sensitive strains.