INVITRO ACTIVITY OF PEFLOXACIN ON HOSPITAL ISOLATES - A MULTICENTER STUDY

Minimal inhibitory concentrations (MICs) of pefloxacin were evaluated by agar dilution for 3422 bacterial strains isolated in nine hospitals. Enterobacteriaceae proved very sensitive to pefloxacin: 62 p. 100 of 1743 strains tested had MIC .ltoreq. 0.12 and 90 p 100 .ltoreq. 1 .mu.g/ml; but the percent of strains with MIC .gtoreq. 2 varied among the different groups of Enterobacteriaceae: 2.7 p. 100 for Escherichia coli to 39 p. 100 for Serratia. 55 p. 100 for Pseudomonas and 81 p. 100 of Acinetobacter were inhibited by 1 .mu.g/ml or less (mode MIC 1 and 0.5 .mu.g/ml). Haemophilus sp.: 0.03 and 0.06 .mu.g/ml and Gonococci were very sensitive to pefloxacin. The spectrum of pefloxacin extended to Gram positive cocci: MIC of Staphylococci were 0.06 to 8 .mu.g/ml (mode MIC : 0.5); Enterococci, other Streptococci and Pneumococci were less sensitive: 2 and 4 .mu.g/ml for the majority of strains. Concerning anaerobic bacteria, pefloxacin was more active against Clostridium (0.5 to 1 .mu.g/ml generally), than against Bacteroides (4 to 16 .mu.g/ml).