Comparative antibacterial activity of the aminothiazolyl cephalosporin RU 29,246

A total of 1,007 clinical isolates from a tertiary care center were tested against RU 29,246, ampicillin, cephalothin, cefoxitin, ceftazidime, Augmentin, oxacillin, piperacillin, gentamicin, amikacin and vancomycin. Bacteria tested consisted of 479 strains of Enterobacteriaceae, 64 pseudomonads, 18 Xanthomonas, 42 other gram-negative bacilli, 56 enterococci and 348 isolates of staphylococci. RU 29,246 showed excellent in vitro activity inhibiting > 90% of Escherichia coli, Klebsiella pneumoniae, K. oxytoca, Enterobacter, Proteus mirabilis, Providencia, Morganella, Salmonella, Shigella, Aeromonas hydrophila, and methicillin-susceptible Staphylococcus aureus at an MIC of 0.5-1.0 mg/l. Seventy-seven percent coagulase-negative staphylococci had an MIC of 1.0-4.0 mg/l. All strains of Pseudomonas aeruginosa and X. maltophilia were resistant to RU 29,246. Fifty-six percent of the enterococcal isolates were inhibited by 1.0-16.0 mg/l of RU 29,246.