Antimicrobial susceptibility of tigecycline and comparators against bacterial isolates collected as part of the TEST study in Europe (2004-2007).

Tigecycline is a broad-spectrum antimicrobial agent that has been approved for the treatment of skin and soft-tissue infections as well as intra-abdominal infections. The Tigecycline Evaluation and Surveillance Trial (TEST) is a global, longitudinal surveillance study established in 2004 to monitor the in vitro activity of tigecycline and comparator agents against key Gram-negative and Gram-positive pathogens. This report examines data obtained for 24748 isolates collected across 24 European countries between 2004 and 2007. Tigecycline, meropenem and imipenem were the most active antimicrobial agents against most Gram-negative isolates including multidrug-resistant Acinetobacter baumannii (15.7% of the A. baumannii isolates in this study), extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (8.5% of E. coli) and ESBL-producing Klebsiella pneumoniae (13.6% of K. pneumoniae). Only amikacin was active against >90% of Pseudomonas aeruginosa isolates (92.8% susceptible). Tigecycline, linezolid and vancomycin were the most active agents against Gram-positive agents across Europe between 2004 and 2007, with tigecycline displaying the lowest MIC(90) values (minimum inhibitory concentration for 90% of the organisms) against meticillin-resistant Staphylococcus aureus (26.5% of the collected S. aureus isolates), vancomycin-resistant Enterococcus faecium (15.7% of the E. faecium strains) and penicillin-resistant Streptococcus pneumoniae (9.3% of the S. pneumoniae strains). Longitudinal analysis showed no increase in tigecycline MIC values over the 4-year study period, whilst increased resistance was noted for several comparator agents.