Penicillin resistance in Escherichia coli K12: synergism between penicillinases and a barrier in the outer part of the envelope.

Ampicillin/pharmacology Bacteria/cytology Carbohydrate Metabolism Cell Membrane/drug effects Chromosomes, Bacterial/metabolism Culture Media Drug Synergism Escherichia coli/cytology,drug effects,enzymology Genes Genotype Hot Temperature Lipopolysaccharides/metabolism Microbial Sensitivity Tests Mutation Penicillin Resistance Penicillinase/biosynthesis,metabolism Penicillins/pharmacology Phenotype Polysaccharides, Bacterial/metabolism Rifampin/pharmacology Time Factors beta-Lactamase Inhibitors

Culture Media Lipopolysaccharides Penicillins Polysaccharides, Bacterial beta-Lactamase Inhibitors Ampicillin Penicillinase Rifampin