[Antibacterial activity of ceftriaxone]

In this study the author reports the main in vitro characteristics of ceftriaxone, a new aminothiazolyl methoxy-iminocephalosporin. The relationship between its structure and the antibacterial activity compared with cefotaxime reveals an expected longer antibacterial efficacy due to a long elimination half-life (8 h). It has been shown that ceftriaxone is highly stable against most either plasmid or chromosome-mediated beta-lactamases. Several studies demonstrated that the spectrum of ceftriaxone included Gram-positive cocci as well as most Gram-negative bacilli even beta-lactamase producers; a variable in vitro activity against Gram-negative aerobic bacteria (Pseudomonas sp., Acinetobacter sp.) has been proved, with a frequent synergistic bactericidal activity when combined with aminoglycosides, or with other beta-lactam antibiotics (carbenicillin, piperacillin). Multiple PBPs targets have been identified, including PBP1b, 2 and 3, leading to filamentation of E. coli, Ps. aeruginosa and Haemophilus cells. As a result, ceftriaxone displays a high intrinsic in vitro activity against troublesome strains and might be considered as a promising new cephalosporin for treatment of severe infections.