Plasmid maintenance in S. typhimurium using the glmS system in vitro.

(A) GlmS mutant (SKS1001) salmonellae carrying s.tGlmS+p were subcultured (1/1000) in minimal media (closed circles) or media supplemented with 0.2% GlcNAc (open circles) every 12 hrs. The fraction of bacteria carrying s.tGlmS+p was determined on the indicated days by the plating method. (B) The same was done with wild-type Salmonellae (SCH2005) in the absence (open circles) or presence (closed circles) of ampicillin.