In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: Tigecycline Evaluation and Surveillance Trial 2004 to 2007

The Tigecycline Evaluation and Surveillance Trial began in 2004 to monitor the in vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive pathogens. Against Grain negatives (n = 63 699), tigecycline MIC90's ranged from 0.25 to 2 mg/L for Escherichia coli, Haemophilus influenzae, Acinetobacter boumannii, Klebsiella oxytoca, Enterobacter cloacae, Klebsiella pneumoniae, and Serratia marcescens (but was >= 32 for Pseudomonas aeruginosa). Against Gram-positive organisms (11 32 218), tigecycline MIC90's were between 0.06 and 0.25 mg/L for Streptococcus pneumoniae, Enterococcus faecium, Streptococcus agalactiae, Staphylococcus aureus, and Enterococcus faecalis. The in vitro activity of tigecycline was maintained against resistant phenotypes, including multidrug-resistant A. baumannii (9.2% of isolates), extended-spectrum beta-lactamase-producing E. coli (7.0%) and K. pneumoniae (14.0%), beta-lactamase-producing H. influenzae (22.2%), methicillin-resistant S. aureus (44.5%), vancomycin-resistant E.faecium (45.9%) and E.faecalis (2.8%), and pencillin-resistant S. pneumoniae (13.8%). Tigecycline represents a welcome addition to the armamentarium against difficult to treat organisms. (C) 2009 Elsevier Inc. All rights reserved.