[In vitro antibacterial activity of prulifloxacin, a new oral fluoroquinolone]

We compared antibacterial activity of NM394, which is the active metabolite of a prodrug of new fluoroquinolone prulifloxacin (PUFX), against clinical isolates of bacteria with those of ciprofloxacin (CPFX), levofloxacin (LVFX), gatifloxacin (GFLX), tosufloxacin (TFLX) and fleroxacin (FLRX). 1. NM394 showed a broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria. 2. MIC80 of NM394 for methicillin-sensitive Staphylococcus aureus, Streptococcus pneumoniae and Enterococcus faecalis were 0.5 microgram/ml, 2 micrograms/ml and 4 micrograms/ml, respectively. MIC80 of NM394 for Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae was lower than 0.06 microgram/ml. MIC80 of NM394 for Serratia marcescens and Pseudomonas aeruginosa were 0.25 microgram/ml and 2 micrograms/ml, respectively. 3. Short-time bactericidal activity of NM394 against P. aeruginosa was stronger than those of CPFX, GFLX, LVFX and TFLX. 4. Short-time bactericidal activity of NM394 at Cmax concentration against 12 strains of P. aeruginosa was stronger than those of CPFX, LVFX, GFLX and TFLX.