THE ANTIMICROBIAL ACTIVITY AND BETA-LACTAMASE STABILITY OF CEFPIROME, A NEW 4TH-GENERATION CEPHALOSPORIN IN COMPARISON WITH OTHER AGENTS

The antimicrobial activity of cefpirome was compared with amoxycillin/clavulanic acid, ampicillin/sulbactam, cefuroxime, ceftazidime, gentamicin and amikacin against 743 non-duplicate clinical isolates. MIC50 and MIC90 showed that the antibiotic was active against both Gram-negative and Gram-positive organisms. Cefpirome was highly active against most of the Enterobacteriaceae, including indole-positive Proteus spp., Aeromonas spp. (MIC ≤ 1 mg/L) and Salmonella spp. (MIC ≤ 0·5 mg/L). Neisseria gonorrhoeae and Haemophilus influenzae (including β-lactamase producers) were all susceptible, with MIC less than 0·5 and 0·25 mg/L respectively. Cefpirome was more active than cefuroxime and ceftazidime against Campylobacter spp. (MIC ≤. 2 mg/L), but less active than ceftazidime against Pseudomonas aeruginosa. Cefpirome was active against Streptococcus pneumoniae. Streptococcus bovis and coagulase-negative staphylococci (MIC ≤ 0·5 mg/L) and methicillin-sensitive Staphylococcus aureus (MIC ≤ 2 mg/L). Methicillin-resistant 5. aureus, Gram-positive and Gram-negative anaerobes were resistant to cefpirome. The stability of cefpirome to TEM-1, TEM-2, PSE-1, SHV-1 and the chromosomal-mediated P99 and K-1 β-lactamases was comparable to ceftazidime. © 1993 The British Society for Antimicrobial Chemotherapy.