RT Journal Article SR Electronic T1 Comparative activity of newer antibiotics against gram-negative bacilli JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 161 OP 166 VO 56 IS 2 A1 Knapp, Cynthia C. A1 Washington, John A. YR 1989 UL http://www.ccjm.org/content/56/2/161.abstract AB The in vitro activities of cefoperazone, cefotaxime, ceftriaxone, ceftazidime, azlocillin, mezlocillin, piperacillin, ticarcillin/clavulanate, aztreonam, imipenem, and ciprofloxacin were concurrently determined against over 1,000 isolates of gram-negative bacilli from clinical specimens of patients at the Cleve-land Clinic. Cephalosporins, penicillins, and aztreonam were active against species of Enterobacteriaceae other than Citrobacter freundii, Enterobacter aerogenes, and Enterobacter cloacae. Ceftazidime was the most active cephalosporin against Pseudomonas aeruginosa. Against the Enterobacteriaceae, the rank order of activity of penicillins was ticarcillin/clavulanate > piperacillin > mezlocillin > azlocillin. Against P. aer-uginosa, the rank order of activity of penicillins was piperacillin > ticarcillin/clavulanate > azlocillin > mezlocillin. Aztreonam was less active v P. aeruginosa than ceftazidime, cefoperazone, or piperacillin. The most active antimicrobials against all isolates tested were imipenem and ciprofloxacin.