Cefixime: spectrum of antibacterial activity against 16,016 clinical isolates.

The spectrum of antibacterial activity of cefixime was defined by reviewing data from two multicenter studies and three independent studies that we performed within the past 3 years. Microdilution tests were performed with 16,016 bacterial isolates. An isolate was considered susceptible to cefixime if the minimal inhibitory concentration was less than or equal to 1.0 microgram/ml and resistant if the minimal inhibitory concentration was greater than or equal to 4.0 micrograms/ml. Cefixime was effective against the Enterobacteriaceae (87.7% susceptible to 1.0 microgram/ml) as well as against pathogenic Neisseria spp. (including penicillin-resistant gonococci), Haemophilus influenzae (including ampicillin-resistant strains), penicillin-susceptible Streptococcus pneumoniae and other Streptococcus species (minimal concentration inhibiting 90% of organisms less than or equal to 0.25 micrograms/ml). Species resistant to cefixime included penicillin-resistant pneumococci, Staphylococcus spp., Enterococcus spp., Listeria spp., Acinetobacter spp. and Pseudomonas spp.