Overcoming imidazole resistance in Escherichia coli.

We have demonstrated that the high resistance to imidazoles in 60 Escherichia coli strains is overcome by lowering the minimum inhibitory concentration (MIC) in culture from > 3200 to < 0.39 micrograms ml(-1) and, by determining, in contact tests, the disappearance of 10(4) CFU with 25 micrograms ml(-1) of imidazoles after 3 min. Although the contact activity was not the same as growth inhibition due to the different target of the drug in the cell structures, we annulled E. coli imidazole resistance in cultural and direct tests by means of the same non-antimicrobial conditions related to outer membrane functions.