TABLE 2.

MICs for various H. pylori strains as determined by E-test

AntibioticMIC (μg/ml)a for H. pylori
Tetr strain 181Reference strain 26695Tetr transformant of strain 26695
Tetracycline80.198
Doxycycline120.1912
Minocycline80.1256
Amoxicillin<0.016<0.016<0.016
Clarithromycin<0.016<0.016<0.016
Metronidazole0.190.0160.064
  • a Data shown are the averages of three independent experiments. The isolates were considered resistant when the MICs of the tetracyclines (tetracycline, doxycycline, and minocycline), amoxicillin, clarithromycin, and metronidazole were ≥4, ≥8, ≥2, and ≥8 μg/ml, respectively (5, 13).