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

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