R-Factor elimination by thymine starvation

Abstract

SUMMARY: R-factor 1818, which is refractory to curing by acridines or ethidium bromide fromEscherichia coliK 12 andKlebsiella aerogenes418 hosts, was eliminated from thymineless mutants of these organisms under conditions of thymine starvation. Neither R-7268 nor R-TEM could be eliminated by this method. The concurrence of R-TEM with R-1818 inhibited the curing of R-1818, whereas R-7268 had no effect on R-1818 elimination