TABLE 2.

Numbers of nonhypermutable or hypermutable isolates for which resistant mutant subpopulations were observed for each antibiotic

AntibioticNo. of isolates with resistant mutants subpopulations observed/no. tested bya:
EtestDisk diffusion
Nonhypermutable isolates (n = 25)Hypermutable isolates (n = 10)Nonhypermutable isolates (n = 25)Hypermutable isolates (n = 10)
Ceftazidime3/259/92/259/9
Imipenem2/258/84/259/9
Meropenem3/2510/105/2510/10
Ciprofloxacin2/259/101/258/10
Tobramycin1/246/101/247/10
  • a Isolates for which the MIC was higher than the highest concentration on the Etest strips were excluded (see Materials and Methods).