Pefloxacin: evolution of in vitro activity during 18 months of use in an intensive care unit.

The MIC of pefloxacin against all the strains (3122) isolated in an intensive care unit during 18 months was studied. The MIC of pefloxacin was estimated by standard agar diffusion method in Mueller-Hinton agar. All the strains with a MIC lower than 2 mg/l were considered as sensitive, between 2 and 4 mg/l as "intermediary" and over 4 mg/l as resistant.