Isolation and characterization of mutants of Escherichia coli K12 resistant to the new aminoglycoside antibiotic, amikacin.

Spontaneous mutants of Escherichia coli K12 that are resistant to the new aminoglycoside antibiotic, amikacin, were isolated. These mutants have simultaneously acquired cross-resistance to kanamycin, gentamicin and neomycin but not to streptomycin or spectinomycin. Sensitivity of the mutant strains to the non-aminoglycoside antibiotics, ampicillin, tetracycline and polymyxin, was unaffected. The mutation responsible for amikacin resistance was mapped by PI transduction and found to be tightly linked to strA, distal with respect to spcA and aroE.