title: In vitro activity of U-63196E, a new cephalosporin, against clinical bacterial isolates.
abstract: The in vitro activity of U-63196E, a new cephalosporin, was compared with those of other extended-spectrum cephalosporins and penicillins against clinical bacterial isolates. Against Pseudomonas aeruginosa, the activity of U-63196E was comparable to those of cefoperazone and piperacillin, each of which inhibited 90% of strains at concentrations of less than or equal to 16 micrograms/ml. The new drug also demonstrated activity against a variety of other bacterial species, but it was generally less active than cefotaxime, moxalactam, and cefoperazone against members of the family Enterobacteriaceae and staphylococci. The presence of any 1 of 10 plasmid-mediated beta-lactamases in a series of otherwise isogenic laboratory strains of P. aeruginosa resulted in a significant reduction in the activity of U-63196E in comparison with its activity against the parent strain, which lacks these enzymes. Combinations of U-63196E with tobramycin demonstrated bacteriostatic synergism against 11 of 20 clinical isolates of P. aeruginosa.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001424:Bacterial Infections / Q000382:microbiology; D002511:Cephalosporins / Q000494:pharmacology*; D004357:Drug Synergism; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D014031:Tobramycin / Q000494:pharmacology; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C038845:cefpimizole; D001618:beta-Lactamases; D014031:Tobramycin