title: In vitro activities of various piperacillin and sulbactam combinations against bacterial pathogens isolated from Intensive Care Units in Taiwan: SMART 2004 programme data.
abstract: We investigated the in vitro activity of various piperacillin and sulbactam combinations against Gram-negative bacterial isolates from Intensive Care Units (ICUs) in Taiwan. Antimicrobial susceptibility testing of 1030 bacterial isolates recovered from ICUs of nine major teaching hospitals was performed using the agar dilution method. Sulbactam was added to piperacillin either at a fixed sulbactam concentration of 4 mg/L and 8 mg/L or at a piperacillin:sulbactam ratio of 2:1 and 4:1. Piperacillin/sulbactam at a ratio of 2:1 or a fixed 8 mg/L concentration of sulbactam had better activities against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Serratia marcescens than other piperacillin/sulbactam formulations. For Pseudomonas aeruginosa, piperacillin/sulbactam (2:1 or 4:1 ratios) had MIC(90) values (minimum inhibitory concentration for 90% of the organisms) of 64 mg/L (>90% susceptibility) compared with 64 mg/L for cefoperazone/sulbactam (68% susceptibility) and 128 mg/L for piperacillin/tazobactam (82% susceptibility). For Acinetobacter baumannii, both piperacillin/sulbactam (either 2:1 ratio or a fixed 8 mg/L sulbactam) and cefoperazone/sulbactam were the most potent agents. Adding sulbactam to piperacillin resulted in increased susceptibility rates among piperacillin-resistant P. aeruginosa (53-57% in either 2:1 or 4:1 ratios) and A. baumannii (38-46% in either 2:1 ratio or a fixed 8 mg/L concentration of sulbactam) isolates. Results of susceptibility tests with piperacillin/sulbactam are dependent on the method used. Piperacillin/sulbactam combinations possessed better in vitro activities than piperacillin alone or piperacillin/tazobactam against P. aeruginosa and A. baumannii.
authors.affiliation: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Min-Nan
authors.initials: MN
authors.lastname: Hung
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.forename: Hou-Tai
authors.initials: HT
authors.lastname: Chang
authors.forename: Wen-Sen
authors.initials: WS
authors.lastname: Lee
authors.forename: Ming-Yuan
authors.initials: MY
authors.lastname: Chou
authors.forename: Ing-Shen
authors.initials: IS
authors.lastname: Chen
authors.forename: Jen-Hsien
authors.initials: JH
authors.lastname: Wang
authors.forename: Chen-Fu
authors.initials: CF
authors.lastname: Lin
authors.forename: Jainn-Ming
authors.initials: JM
authors.lastname: Shyr
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Ko
authors.forename: Jiunn-Jong
authors.initials: JJ
authors.lastname: Wu
authors.forename: Yung-Ching
authors.initials: YC
authors.lastname: Liu
authors.forename: Wen-Kuei
authors.initials: WK
authors.lastname: Huang
authors.forename: Lee-Jene
authors.initials: LJ
authors.lastname: Teng
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Liu
authors.forename: Kwen-Tay
authors.initials: KT
authors.lastname: Luh
mesh_terms: D001419:Bacteria / Q000187:drug effects*; D002438:Cefoperazone / Q000008:administration & dosage*; D004338:Drug Combinations; D006801:Humans; D007362:Intensive Care Units; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives*; D010878:Piperacillin / Q000008:administration & dosage*; D013407:Sulbactam / Q000008:administration & dosage*; D000078142:Tazobactam
chemical_list: D004338:Drug Combinations; D002438:Cefoperazone; D010397:Penicillanic Acid; D013407:Sulbactam; D000078142:Tazobactam; D010878:Piperacillin