An evaluation of the bacteriolytic and biochemical properties of ceftiolene (42980

Ceftiolene (42980RP) is a new cephalosporin with a broad antibacterial spectrum similar to cefotaxime or ceftriaxone. The characteristics of ceftiolene have been tested in a variety of assays involving various biochemical aspects of the mode of action of /?-lactam antibiotics. The affinities of ceftiolene for penicillin-binding proteins were very comparable with those of ceftriaxone and cefotaxime for Escherichia coli, and generally greater than those of latamoxef (moxalactam) for the higher molecular weight PBPs of E. coli. Enterobacter cloacae. Proteus mirabilis and Pseudomonas aeruginosa. The affinity of ceftiolene for PBP1 of Staphylococcus aureus was greater than those of cefotaxime or latamoxef, but comparable with these antibiotics for PBP3. The bacteriolytic activity of ceftiolene at denned concentrations against Gram-negative organisms was similar to that of ceftriaxone, and significantly better than that of the other third-generation cephalosporins tested. Introduction of plasmid-encoded /J-lactamases into E. coli reduced the wide variation in bacteriolytic effect of the different cephalosporins, and a significant inoculum effect was observed for the bacterio