The beta-lactam hydrolysis of five cephalosporin 3'-quinolones (dual-action cephalosporins) by three gram-negative beta-lactamases was examined. The dual-action cephalosporins tested were the ester Ro 23-9424; the carbamates Ro 25-2016, Ro 25-4095, and Ro 25-4835; and the tertiary amine Ro 25-0534. Also tested were cephalosporins with similar side chains (cefotaxime, desacetylcefotaxime, cephalothin, cephacetrile, and Ro 09-1227 [SR 0124]) and standard beta-lactams (penicillin G, cephaloridine). The beta-lactamases used were the plasmid-mediated TEM-1 and TEM-3 enzymes and the chromosomal AmpC. The cephacetrile-related compounds Ro 25-4095 and Ro 25-4835 were hydrolyzed by all three beta-lactamases with catalytic efficiencies (relative to penicillin G) ranging from approximately 5 (TEM-1, AmpC) to approximately 25 (TEM-3). The cephalothin-related Ro 25-2016 was also hydrolyzed by all three beta-lactamases, particularly the AmpC enzyme (relative catalytic efficiency, 110). The cefotaxime-related compounds Ro 25-0534 and Ro 23-9424 were hydrolyzed to any significant extent only by the TEM-3 enzyme (relative catalytic efficiencies, 1.2 and 4.7, respectively.

1994-01-01·Diagnostic microbiology and infectious disease4区 · 医学

Antimicrobial activity of a new antipseudomonal dual-action drug, Ro 25-0534

4区 · 医学

Article

作者: Ronald N. Jones ; Martha L. Sanchez

Ro 25-0534, a tertiary amine-linked dual action combination (DAC) of a catechol cephalosporin and ciprofloxacin, was compared with a previously described DAC (Ro 23-9424), ciprofloxacin and cefotaxime. A total of 688 recent clinical isolates were tested and an additional collection of 110 Gram-negative bacilli possessing documented resistance to broad-spectrum antimicrobials were used. Ro 25-0534 was active against all tested species of Enterobacteriaceae (MIC90 range, 0.06-2 micrograms/ml), oxacillin-susceptible staphylococci, beta-hemolytic streptococci, and penicillin-susceptible pneumococci (MIC90 range, 1-2 micrograms/ml). Haemophilus influenzae (MIC90 range, 0.25-0.5 micrograms/ml), Moraxella catarrhalis (MIC90, 0.5 microgram/ml), and most nonenteric Gram-negative bacilli (MIC90 range, 2-4 micrograms/ml) such as Pseudomonas aeruginosa, Acinetobacter spp., and Xanthomonas maltophilia. Enterococci and Bacteroides fragilis isolates were resistant to Ro 25-0534. The Ro 25-0354 potency against most susceptible strains was generally severalfold less than that of Ro 23-9424 (except for Pseudomonas-Xanthomonas) or ciprofloxacin alone.

100 项与 RO-250534 相关的药物交易

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