In vitro activity of lascufloxacin, a novel fluoroquinolone antibacterial agent, against various clinical isolates of anaerobes and Streptococcus anginosus group

The in vitro activities of lascufloxacin were evaluated by comparison with seven reference compounds using 412 clinical isolates of anaerobes and Streptococcus anginosus group. Lascufloxacin showed potent and broad antibacterial activities greater than those of existing quinolones against the clinical isolates used in this study. •The MIC90 of LSX against C. difficile was 8-fold less than that of MFX.•LSX showed strong activities against respiratory anaerobes and oral streptococci.•The MICs90 of LSX against S. anginosus group were similar to MEM, superior to MFX.•LSX exhibited excellent MIC90 against P. melaninogenica and P. intermedia.