Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2001 - I. Gram-positive bacteria

The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2001 were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, and penicillins. A total of 1,274 strains in 15 species of Gram-positive bacteria were isolated from the clinical materials annually collected from January to December, and consisted of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Staphylococcus haemolyticus, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus faecalis, Enterococcus faecium, Enterococcus avium, and Peptostreptococcus spp. CZOP possessed stable antibacterial activities against all strains tested throughout 6 years. The MIC₉₀ of CZOP against MRSA and S. haemolyticus tended to decrease while against S. pneumoniae and Peptostreptococcus spp., tended to increase year by year. However, the MIC ₉₀ just changed a little and were consistent with the results from the studies performed until the new drug application approval. Increases in the MIC₉₀ against S. pneumoniae were also observed with ceftazidime (CPR), cefepime (CFPM), flomoxef (FMOX), sulbactam/cefoperazone (SBT/CPZ), and imipenem (IPM). Increases in the MIC₉₀ against Peptostreptococcus spp. were also observed with FMOX, SBT/CPZ, and IPM. In conclusion, the annual antibacterial activities of CZOP against the Gram-positive bacteria did not considerably change. It, therefore, was suggested that CZOP had maintained high antibacterial activity during 6 years of post marketing.