title: LY127935, a novel oxa-beta-lactam: an in vitro comparison with other beta-lactam antibiotics.
abstract: The in vitro activities of LY127935 (LY) were compared with those of other beta-lactam antibiotics. LY was highly active (minimal inhibitory concentration [MIC] range 0.06 to 0.25 micrograms/ml) against the common Enterobacteriaceae (including Providencia stuartiia, Enterobacter, and Serrati marcescens), 8 to 16 times more active than cefoxitin, cefuroxime, or cefazolin, and from one-half to one-eighth as active as cefotaxime (HR756). The activity of LY against Pseudomonas aeruginosa (with MICs of 4 and 64 micrograms/ml for 50 and 90% of test strains, respectively) was essentially similar to that of cefotaxime, but was only one-half as active as CGP 7174/E. LY, cefoxitin, and cefotaxime were essentially equally active against Bacteroides fragilis--each was more active than cefuroxime and cefazolin. Against Staphylococcus aureus, LY (50% MIC and 90% MIC of 4 and 16 micrograms/ml, respectively) was less active than cefotaxime, cefoxitin, or cefuroxime and one-eighth as active as cefazolin. The composition and pH of the culture medium had little effect on the activity of LY, although 7.2 appeared to be the optimum pH.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002511:Cephalosporins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D047090:beta-Lactams