In vitro antibacterial activity of ceftizoxime

During 1983, the antibacterial activity of ceftizoxime has been tested in vitro against 325 strains of Enterobacteriaceae, Streptococcaceae, Micrococcaceae, Pseudomonaceae and Acinetobacter sp. isolated from material of human origin (blood, urine, faeces, sputum, various exudates). Except for S. faecalis and some strains of P. rettgeri, P. aeruginosa, A. calcoaceticus, Staphylococcus spp. all the strains examined were found to be sensitive to the antibiotic, whose MIC was 0.05-1.5 micrograms/ml in the great majority of cases. For 72 ceftizoxime-sensitive strains the MBC/MIC ratio was nearly always under 4:1, confirming the drug's bactericidal activity. On strains of Enterobacteriaceae (E. coli, K. pneumoniae, S. marcescens, S. typhimurium) MIC of ceftizoxime achieved a minimum bactericidal time (MBT) between 3 and 4 hours of bacteria-antibiotic contact, and bacterial survival percentages were, in any case, very low as early as the 1st hour.