title: Piperacillin/tazobactam (YTR 830) combination. Comparative antimicrobial activity against 5889 recent aerobic clinical isolates and 60 Bacteroides fragilis group strains.
abstract: Piperacillin combined with tazobactam (formerly YTR 830) was tested at a ratio of 8:1 against 5889 aerobic isolates and 50 strains from the Bacteroides fragilis group. Imipenem was the most active agent tested against Enterobacteriaceae (99.3% at less than or equal to 4 micrograms/ml), ceftazidime was most effective against nonenteric Gram-negative bacilli (80.7% at less than or equal to 8 micrograms/ml), and piperacillin/tazobactam possessed a superior spectrum against Gram-positive cocci (92.2% at less than or equal to 16/2 micrograms/ml). Against all aerobic strains, piperacillin/tazobactam had a spectrum (90.3% at less than or equal to 16/2 micrograms/ml) comparable to imipenem (93.6% at less than or equal to 4 micrograms/ml) and was distinctly greater than that of ticarcillin/clavulanic acid (73.3% at less than or equal to 16/2 micrograms/ml) and ceftazidime (75.5% at less than or equal to 8 micrograms/ml). Against the B. fragilis group isolates, all piperacillin/tazobactam MICs were less than or equal to 64/8 micrograms/ml. This activity was superior to piperacillin alone (MIC:50, 8-64 micrograms/ml) and cefoxitin (MIC50, 4-64 micrograms/ml). Piperacillin/tazobactam appears to be a promising parenteral antimicrobial combination, with a spectrum effective against a wide variety of clinical pathogens.
authors.affiliation: Clinical Microbiology Institute, Tualatin, Oregon.
authors.forename: R N
authors.initials: RN
authors.lastname: Jones
authors.forename: M A
authors.initials: MA
authors.lastname: Pfaller
authors.forename: P C
authors.initials: PC
authors.lastname: Fuchs
authors.forename: K
authors.initials: K
authors.lastname: Aldridge
authors.forename: S D
authors.initials: SD
authors.lastname: Allen
authors.forename: E H
authors.initials: EH
authors.lastname: Gerlach
mesh_terms: D001420:Bacteria, Aerobic / Q000187:drug effects*; D001441:Bacteroides fragilis / Q000187:drug effects*; D002442:Ceftazidime / Q000494:pharmacology; D002969:Clavulanic Acids / Q000494:pharmacology; D004338:Drug Combinations; D004359:Drug Therapy, Combination / Q000494:pharmacology; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D010397:Penicillanic Acid / Q000494:pharmacology*; D010878:Piperacillin / Q000494:pharmacology*; D000078142:Tazobactam; D013982:Ticarcillin / Q000494:pharmacology; D065093:beta-Lactamase Inhibitors
chemical_list: D002969:Clavulanic Acids; D004338:Drug Combinations; D065093:beta-Lactamase Inhibitors; D015378:Imipenem; C043215:ticarcillin-clavulanic acid; D010397:Penicillanic Acid; D002442:Ceftazidime; D013982:Ticarcillin; D000078142:Tazobactam; D010878:Piperacillin