Activities of gemifloxacin (SB 265805, LB20304) compared to those of otheroral antimicrobial agents against unusual anaerobes

The activities of gemifloxacin (SB 265805, LB20304) and comparator agents w ere determined by an agar dilution method against 419 clinical strains of l ess commonly identified species of anaerobes. Gemifloxacin was generally mo re active than trovafloxacin against gram-positive strains by one to two di lutions. Peptostreptococci (Peptostreptococcus asaccharolyticus, Peptostrep tococcus magnus, Peptostreptococcus micros, and Peptostreptococcus prevotii ) and Porphyromonas spp. (Porphyromonas asaccharolytica, Porphyromonas cano ris, Porphyromonas gingivalis, and Porphyromonas macacae) were all suscepti ble to less than or equal to 0.25 mu g of gemifloxacin per mi, The MICs of gemifloxacin at which 90% of the following strains were inhibited (MIC(90)s ) were less than or equal to 2 mu g/ml: Actinomyces israelii, Actinomyces o dontolyticus, Clostridium innocuum, Clostridium clostridioforme, Anaerobios pirillum spp., Bacteroides tectum, Bacteroides ureolyticus, Bacteroides gra cilis (now Campylobacter gracilis), Prevotella intermedia, Prevotella hepar inolytica, and the Prevotella oris-buccae group. Fusobacterium naviforme an d Fusobacterium necrophorum were also susceptible to less than or equal to 2 mu g of gemifloxacin per mi, while Fusobacterium varium strains exhibited a bimodal pattern; the other Fusobacterium species, such as Fusobacterium ulcerans and Fusobacterium rusii, as well as Veillonella spp,, the Prevotel la melaninogenica group, Prevotella bivia, Clostridium difficile, and Bilop hila wadsworthia were relatively resistant to gemifloxacin (MIC(90)s, great er than or equal to 4 mu g/ml).