Spontaneous kanamycin-resistant Escherichia coli mutant with altered periplasmic oligopeptide permease protein (OppA) and impermeability to aminoglycosides

Abstract

A spontaneous kanamycin-resistant Escherichia coli mutant, showing cross resistance to five other aminoglycosides and absence of the OppA protein was isolated. [ 3 H]-dihydrostreptomycin uptake is reduced in this mutant, implying that the oligopeptide transport system is involved in accumulation of aminoglycosides, although apparently not related with aminoglycoside permeability alteration due to bacterial adaptation to osmotic changes.

Altered expression of oligopeptide-binding protein (OppA) and aminoglycoside resistance in laboratory and clinical Escherichia coli strains

“…A rapid initial electrostatic binding to the outer surface is followed by a slow uptake termed`energy-dependent phase I' (EDP I) [2,20], which gives way to enhanced accumulation as mistranslated proteins, generated by the antibiotic's action on ribosomes, are incorporated into the cytoplasmic membrane, disrupting its barrier function [21,22]. Recent evidence indicates that the accumulation of aminoglycosides during EDP I in E. coli K-12 may include the action of an oligopeptide uptake system carrier, the OppA permease [6,7,9]. OppA binds di-to penta-pepides, independent of sequence, and so has many potential ligands, including cell wall peptides, and also peptide-based and aminoglycoside antibiotics [23±25].…”

Oligopeptide uptake and aminoglycoside resistance in Escherichia coli K12

“…Previous results based on another E. coli K12 strain (J53 strain) indicated that some mutants selected for aminoglycoside resistance expressed reduced OppA levels (Kashiwagi et al , 1992; Rodriguez et al , 1995; Rodriguez & Costa, 1999; Acosta et al , 2000). These contrasting results may be reasoned by the methodological differences used by the two groups in the evaluation of aminoglycoside resistance and the genetic background of the tested strains.…”

“…These contrasting results may be reasoned by the methodological differences used by the two groups in the evaluation of aminoglycoside resistance and the genetic background of the tested strains. Additionally, the high spontaneous mutation frequencies to aminoglycoside resistance, particularly under high osmolarity conditions, may lead to mutants expressing reduced OppA levels, which is also a rather frequently mutational event (Barak & Gilvarg, 1974; Rodriguez & Costa, 1999; Monteiro et al , 2003).…”

“…Kanamycin‐resistant Escherichia coli K12 mutants expressing reduced oligogopeptide permease protein A (OppA) levels, the soluble binding component of the oligogopeptide permease (Opp) uptake system, have been reported previously (Rodriguez et al , 1995; Rodriguez & Costa, 1999; Acosta et al , 2000). Similarly, expression of OppA has been reported to increase aminoglycoside sensitivity in one E. coli K12 strain (Kashiwagi et al , 1992).…”

Intracellular polyamine pools, oligopeptide-binding protein A expression, and resistance to aminoglycosides in Escherichia coli

“…Moreover, the observation that intracellular polyamine pools regulate OppA expression indicated that polyamines could indirectly affect the cell envelope permeability to aminoglycoside antibiotics (Kashiwagi et al 1998). Indeed the high incidence of reduced OppA expression and defective production of enzymes involved in polyamine synthesis, detected both among in vitro selected E. coli K12 mutants as well as among pathogenic strains isolated from clinical settings, further emphasizes the relationship between aminoglycoside resistance, OppA and polyamine metabolism (Rodriguez & Costa 1999, Acosta et al 2000.…”