Antimicrobial Susceptibility among European Gram-Negative and Gram-Positive Isolates Collected as Part of the Tigecycline Evaluation and Surveillance Trial (2004-2014).

BACKGROUND European centers (n = 226) involved in the Tigecycline Evaluation and Surveillance Trial (TEST, 2004-2014) submitted data and bacterial isolates. METHODS Minimal inhibitory concentrations and susceptibility were determined using Clinical and Laboratory Standards Institute methods and European Committee on Antimicrobial Susceptibility Testing breakpoints. RESULTS The rates of the following resistant pathogens increased from 2004 to 2014: extended-spectrum β-lactamase (ESBL)-positive Escherichia coli (from 8.9 to 16.9%), multidrug-resistant Acinetobacter baumannii complex (from 15.4 to 48.5%), and ESBL-positive Klebsiella pneumoniae (from 17.2 to 23.7%). The rate of methicillin-resistant Staphylococcus aureus was 27.5% in 2004 and 28.9% in 2014. Resistance to the carbapenems (imipenem and meropenem) was 37.4 and 14.5% for A. baumannii complex and Pseudomonas aeruginosa, respectively. Carbapenem resistance was ≤4.3% among the Enterobacteriaceae and 0.2% against Streptococcus pneumoniae. The resistance to tigecycline ranged between 7.4% against ESBL-producing K. pneumoniae and 0.0% against S. aureus. CONCLUSIONS The carbapenems and tigecycline were active against Enterobacteriaceae. Agents with activity against A. baumannii complex and P. aeruginosa are limited. The carbapenems, tigecycline, linezolid, and vancomycin were active against Gram-positive organisms.