title: Oligopeptide uptake and aminoglycoside resistance in Escherichia coli K12.
abstract: Previous reports have suggested that Escherichia coli K12 mutants defective in the expression of oligogopeptide permease protein A (OppA) exhibit reduced sensitivity to aminoglycosides due to altered permeability of the cell envelope. In this work, the role of the OppA protein, and the oligogopeptide permease (Opp) transport system has been evaluated, in the resistance to aminoglycosides using derivatives of the E. coli K12 SS320 strain selected for triornithine resistance or with a deletion of the complete opp operon. All tested mutants were defective in the uptake of tri- and tetra-peptides but did not expressed resistance to aminoglycosides. Additionally, complementation tests carried out with a plasmid encoding the OppA protein did not affect the sensitivity of the strains to these antibiotics. Taken together, these evidences indicate that the Opp uptake system, as well as the OppA protein, does not play a direct role in the sensitivity to aminoglycosides in E. coli K12.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Cidade Universitária, São Paulo, Brazil.
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Nakamatsu
authors.forename: Erica
authors.initials: E
authors.lastname: Fujihira
authors.forename: Rita C C
authors.initials: RC
authors.lastname: Ferreira
authors.forename: Andréa
authors.initials: A
authors.lastname: Balan
authors.forename: Sérgio O P
authors.initials: SO
authors.lastname: Costa
authors.forename: Luís C S
authors.initials: LC
authors.lastname: Ferreira
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D048168:Escherichia coli K12 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009842:Oligopeptides / Q000378:metabolism*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D026901:Membrane Transport Proteins; D009842:Oligopeptides; C499290:OppA protein, E coli; C037230:oligopeptide permease, Bacteria