title: Effects of environment on compensatory mutations to ameliorate costs of antibiotic resistance.
abstract: Most types of antibiotic resistance impose a biological cost on bacterial fitness. These costs can be compensated, usually without loss of resistance, by second-site mutations during the evolution of the resistant bacteria in an experimental host or in a laboratory medium. Different fitness-compensating mutations were selected depending on whether the bacteria evolved through serial passage in mice or in a laboratory medium. This difference in mutation spectra was caused by either a growth condition-specific formation or selection of the compensated mutants. These results suggest that bacterial evolution to reduce the costs of antibiotic resistance can take different trajectories within and outside a host.
authors.affiliation: Department of Bacteriology, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Björkman
authors.forename: I
authors.initials: I
authors.lastname: Nagaev
authors.forename: O G
authors.initials: OG
authors.lastname: Berg
authors.forename: D
authors.initials: D
authors.lastname: Hughes
authors.forename: D I
authors.initials: DI
authors.lastname: Andersson
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017920:Antiporters; D002352:Carrier Proteins / Q000235:genetics; D003470:Culture Media; D004352:Drug Resistance, Microbial / Q000235:genetics*; D029968:Escherichia coli Proteins; D019143:Evolution, Molecular; D005260:Female; D005672:Fusidic Acid / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D020653:Peptide Elongation Factor G / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D012641:Selection, Genetic; D012692:Serial Passage; D013307:Streptomycin / Q000494:pharmacology; D013489:Suppression, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D017920:Antiporters; D002352:Carrier Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D020653:Peptide Elongation Factor G; D012269:Ribosomal Proteins; C034212:ribosomal protein S12; C075436:EmrE protein, E coli; D005672:Fusidic Acid; D013307:Streptomycin