ANTIBACTERIAL ACTIVITY OF AM-1155 AGAINST PENICILLIN-RESISTANT STREPTOCOCCUS-PNEUMONIAE

AM-1155, a novel fluoroquinolone, exhibited potent activity against St reptococcus pneumoniae, including penicillin-resistant strains; the MI C90 for 48 clinical isolates was 0.25 mg/L. The antibacterial activity of AM-1155 against S. pneumoniae was higher than that of levofloxacin (MIC90 1 mg/L) and comparable with that of sparfloxacin. The MIC(90)s of penicillin G and erythromycin were 2 and > 4 mg/L, respectively, A M-1155 showed no cross-resistance to penicillin or erythromycin, For e xperimental murine pneumonia with S. pneumoniae intermediately resista nt to penicillin, oral administration of AM-1155 showed efficacy highe r than that of levofloxacin and equal to that of sparfloxacin. The eff icacy of AM-1155 was also equal to that of subcutaneous penicillin G a dministration at the same dosage.