[Antimicrobial activities of roxithromycin against recently obtained clinical isolates]

The purpose of our investigation was to monitor current trends in the susceptibility patterns of clinical bacterial isolates to roxithromycin (RXM). We measured the MICs of macrolide antibiotics, such as RXM, erythromycin (EM), clarithromycin (CAM), rokitamycin (RKM) and midecamycin (MDM), and other classes of antibacterial compounds against various clinical isolates at seven institutions between October and December in 1994 and 1995. RXM had excellent antibacterial activities for S. pyogenes, S. agalactiae, M. (B.) catarrhalis and methicillin sensitive S. aureus. Against methicillin sensitive S. epidermidis, RXM activity was fairly good but about 20% of the strains had MIC > or = 128 micrograms/ml. The activity against S. pneumoniae was not so potent and similar to activities of EM, CAM, MDM, and clindamycin. The vast majority of methicillin resistant S. aureus and S. epidermidis were also resistant to macrolide antibiotics and other classes of compounds tested. In conclusion, RXM is an unique macrolide antibiotic by retaining potent activity against S. pyogenes, S. agalactiae, S. aureus except MRSA, M. (B.) catarrhalis and M. pneumoniae.