[Comparative evaluation of the antibacterial activity of cefotaxime and cephalotin by using an automated...

Cefotaxime is a new broad-spectrum injectable cephalosporin which is stable to most beta-lactamases. In this study we have evaluated the antibacterial activity of cefotaxime comparatively with the activity of cephalotin against 66 Gram-negative bacteria and 31 Gram-positive bacteria by using an automated antimicrobial susceptibility determination system. Cefotaxime was markedly more active than cephalotin against Klebsiella pneumoniae, Proteus, Enterobacter, Escherichia coli and Serratia. Against Gram-positive clinical isolates cefotaxime was less active than cephalotin. Regrowth was observed mainly with cephalotin against Gram-negative clinical isolates, therefore the results obtained after a few hours with automated system should be carefully interpreted.