Comparative in vitro activity of newer cephalosporins

ABSTRACT

To determine the in vitro activity of six new cephalosporins. Determination of minimum inhibitory concentration of new drugs and their comparison with commercially available cephalosporins in clinical use against recent clinical isolates. King Faisal Specialist Hospital and Research Centre, Riyadh [KFSH and RC], Saudi Arabia. 897 bacteria recently isolated from clinical specimens of patients at KFSH and RC. Cefepime, cefpirome, GR 691 53 and Ro 09-1428 were the most active agents against Enterobacteriaceae and Aeromonas hydrophila, inhibiting >90% of them at Pseudomonas aeruginosa followed by cefepime, GR 69153 and cefpirome. Cefdinir and RU 29 246 were ineffective against pseudomonads and xanthomonads. All the six were inhibitory towards streptococci and methicillin-susceptible Staphylococcus aureus. Cefdinir and cefpirome were the only cephalosporins with any appreciable activity against enterococci. Newer parenteral cephalosporins were more active against Enterobacteriaceae than orally active agents. Ro 09-1428, cefepime and GR 691 53 had excellent activity against P. aeruginosa. All were active against streptococci and methicillin-susceptible S. aureus