In vitro activity of LY127935.

The activity of LY127935, a beta-lactam antibiotic of novel structure, was studied in vitro against facultative gram-negative bacilli, Staphylococcus aureus, and Bacteroides fragilis. The strains were recent clinical isolates, many of which were relatively resistant to other antibiotics. LY127935 exhibited striking activity against Escherichia coli, Klebsiella pneumoniae, Enterobacter sp., Proteus sp., Serratia marcescens, and B. fragilis with median minimum inhibitory concentrations of less than or equal to 1.0 micrograms/ml. It was somewhat less active against Pseudomonas aeruginosa and S. aureus. Cefotaxime (HR 756) showed very similar activity except that it was substantially weaker against B. fragilis. LY127935 was more active than cefamandole, cefoxitin, or piperacillin; it was also as potent as tobramycin or amikacin against all species except for P. aeruginosa.