The aac(6')Ib gene in Proteus mirabilis strains resistant to aminoglycosides

The aim of this study was to evaluate the presence of aac(6')-Ib gene conferring resistance to aminoglycosides in Proteus mirabilis strains. Five isolates had aac(6')-Ib gene. In one case the gene was no-expressed. Three isolates were resistant to all aminoglycosides and minimum inhibitory concentrations were > or = 256 microg/ml. Additionally, all positive strains were resistant to tetracycline and ciprofloxacin.