The Comparative Activity of Fleroxacin, Three Other Quinolones and Eight Unrelated Antimicrobial Agents

Abstract

The in vitro activity of fleroxacin, a new trifluorinated quinolone was evaluated against 432 bacterial isolates. Fleroxacin was 1- to 2-fold less active than ciprofloxacin and at least as active as ofloxacin and lomefloxacin against most members of the family Enterobacteriaceae. The MICs of fleroxacin for 90% of strains tested (MIC₉₀) were ≤0.25 μg/ml against all isolates of Enterobacteriaceae except Citrobacter freundii (MIC₉₀, 4 μg/ml) and Serratia marcescens (MIC₉₀, 2 μg/ml). Fleroxacin was as active as ciprofloxacin, ofloxacin and lomefloxacin against Pseudomonas spp, (MIC₉₀ for all quinolones tested were > 8 μg/ml). Acinetobacter and Haemophilus influenzae were very susceptible to fleroxacin; however fleroxacin was 1-fold less active than lomefloxacin against Acinetobacter and at least 1-fold less active than ciprofloxacin or ofloxacin against H. influenzae. Methicillin-susceptible and -resistant strains of Staphylococcus epidermidis and methicillin-susceptible strains of S. aureus were very susceptible to fleroxacin, with an MIC₉₀≤1 μg/ml (range 0.5-1 μg/ml). Methicillin-resistant S.aureus and Staphylococcus spp. other than aureus and epidermidis were not susceptible to fleroxacin (MIC₉₀ > 8 μg/ml). In addition, fleroxacin as well as ciprofloxacin, ofloxacin and lomefloxacin were inactive against Enterococcus spp. (MIC₉₀ > 8 μg/ml). Streptococcus pneumoniae and S. pyogenes were resistant to both fleroxacin and lomefloxacin but were very susceptible to ciprofloxacin and ofloxacin. These results suggest that fleroxacin represents a valid therapeutic option in the treatment of infections caused by most Enterobacteriaceae and some species of staphylococcus.

Comparative in vitro Activity of Fleroxacin, Two Other Quinolones and Three Broad-Spectrum Beta-Lactams Using the E-Test

“…Cipro floxacin showed the best activity against P. ae ruginosa with a MIC,0 of 3 mg/1 and was more active than ofloxacin and fleroxacin with MICX )S of 24 and 32 mg/1, respectively. These results are generally comparable to those ob tained in other studies [11,12]. The MICyoS for fleroxacin, ofloxacin and ciprofloxacin of 4, 3 and 0.38 mg/1 against Salmonella spp.…”

A Multicenter Comparative Study of the in vitro Activity of Fleroxacin and Other Antimicrobial Agents

“…These results of the activity of fleroxacin and other antibiotics against 2,079 bacterial isolates support and extend, with few excep tions, a previously published study of the in vitro efficacy of fleroxacin against just 432 bacterial isolates [24], In the present study, S. epidermidis was 16-fold more resistant to the quinolone antibiotics than in the earlier study [24], The reasons for this difference are unclear, but are not likely related to differ ences in methodology since the type of media, the inoculum preparation, and the culture conditions appeared to be essentially the same.…”