Ofloxacin: in vitro activity against recently isolated gram-negative bacterial strains.

The activity of ofloxacin was determined against 117 Enterobacteriaceae, 13 Acinetobacter var, anitratus, 124 Pseudomonas aeruginosa in comparison with other antibiotics. Its activity was very high: against Enterobacteriaceae the minimum inhibitory concentration (MIC)50 was 0.125 micrograms/ml, the MIC90 1 micrograms/ml, and the geometric mean (GM) was 0.4 micrograms/ml against Acinetobacter var. anitratus the MIC50 1 micrograms/ml, MIC90 4 micrograms/ml, GM 1.7 micrograms/ml. Unlike other authors we found that the activity of ofloxacin was influenced by the selection of P. aeruginosa resistant to carbenicillin and gentamicin.