title: In vitro activity and beta-lactamase stability of U-63196E, a novel cephalosporin.
abstract: The in vitro activity of U-63196E, a new broad-spectrum cephalosporin antibiotic, was studied against various gram-positive and gram-negative bacteria and compared with the in vitro activities of cefotaxime, moxalactam, cefoperazone, ceftazidime, and aztreonam. Although U-63196E inhibited many ampicillin-resistant bacteria and its activity against gram-negative species was similar to cefoperazone, it was much less active than the other agents. U-63196E was less active than cefazolin against gram-positive species, and it was less active than cefoxitin or moxalactam against Bacteroides fragilis. U-63196E did not inhibit most cefoperazone- or cefsulodin-resistant Pseudomonas aeruginosa. There was a difference between minimal inhibitory concentrations and minimal bactericidal concentrations for isolates which contained beta-lactamases. Plasmid beta-lactamases of the TEM, HSV, OXA, and PSE types hydrolyzed U-63196E. But U-63196E was relatively stable against hydrolysis by the chromosomal beta-lactamases.
mesh_terms: D001419:Bacteria / Q000187:drug effects; D002463:Cell Membrane Permeability; D002510:Cephalosporinase / Q000378:metabolism*; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004355:Drug Stability; D010957:Plasmids; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; C038845:cefpimizole; D002510:Cephalosporinase; D001618:beta-Lactamases