IN-VITRO ACTIVITY OF RO-23-9424, A DUAL-ACTING CEPHALOSPORIN-QUINOLONE ANTIMICROBIAL AGENT

In vitro activity of new dual-acting antibacterial Ro 23-9429 was test ed against 1294 bacterial isolates from patients in a major tertiary c are referral hospital in Saudi Arabia. Its activity was compared with that of ciprofloxacin, fleroxacin, ampicillin, cephalothin, cefoxitin, cefotaxime, ceftazidime, piperacillin, oxacillin, gentamicin, amikaci n, imipenem, and vancomycin. Of the 621 members of Enterobacteriaceae tested, every single isolate was inhibited by Ro 23-9429 at minimum in hibitory concentration ranging between <.03 and 8 mug/mL. No other ant imicrobial tested was as active as this dual-acting cephalosporin-fluo roqinolone. Similarly, all of the 255 isolates of Acinotobacter, Aerom onas hydrophila, Pseudomonas aeruginosa, and Xanthomonas maltophilia w ere susceptible to Ro 23-9429. It inhibited all the 120 isolates of me thicillin-resistant Staphylococcus aureus. Its in vitro activity again st coagulase-negative staphylococci and enterococci was superior or co mparable to that of other drugs that are commonly used in clinical pra ctice.