Establishment of resistant strain.
One metronidazole-resistant strain, denoted 26695-1MET, derived from the wild-type metro- nidazole-susceptible strain 26695-1, was obtained via exposure to low concentrations of metronidazole (up to 16.0 mg/liter) (Table 1). The final MICs were 128 mg/liter for 26695-1MET and 4 mg/ liter for 26695-1.