[Cefotaxime, syn isomer of a new methoxyimino cephalosporin with unusual activity (author's transl)].

Cefotaxime, the - syn - derivative of 7 - [(2-(2-amino-4-4-thiazolyl)-2-methoxyimino) acetamido] cephalosporanic acid, is a new semisynthetic cephalosporin. In in vitro studies, it was 80 times more active than the - anti - derivative against beta-lactamase-producing strains of Gram-negative bacteria. The range of inhibitory concentrations of cefotaxime against Gram-negative bacteria, including Haemophilus influenzae, susceptible or resistant to penicillins and cephalosporins was from 0.01 to 0.1 micrograms/ml. This activity was consistently higher than that observed with cephalothin, cephaloridine, cephalexin, and cefazolin. Nevertheless, some strains of Enterobacter cloacae were resistant. Cefotaxime showed very similar activity to that of ampicillin against group A streptococci and Streptococcus pneumoniae.