title: The influence of the growth environment on the stability of a drug resistance plasmid in Escherichia coli K12.
abstract: Populations of Escherichi coli K12 containing the plasmid TP120 which coded for resistance to ampicillin, streptomycin, sulphonamide and tetracycline were grown in a chemostat under carbon-limited and phosphorus-limited conditions. With time resistance to one or more of the drugs was lost, resulting in the production of mutant populations which were more competitive than the parent population. The resistance to tetracycline was always lost under both carbon and phosphorus limitations, but resistance to the other three drugs was lost only during phosphate-limited growth. Strains of E. coli which had lost resistance to one or more of the drugs were capable of higher maximum specific growth rates than the parent strain.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003470:Culture Media; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D005947:Glucose; D010710:Phosphates; D010957:Plasmids / Q000187:drug effects*; D013752:Tetracycline / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D010710:Phosphates; D013752:Tetracycline; D005947:Glucose