Susceptibility of common aerobic pathogens to tigecycline: results of a surveillance study in Germany

Tigecycline is a novel antimicrobial agent for parenteral use encompassing a broad spectrum of bacterial pathogens, including multi-resistant organisms. Here, we report the results of the first nationwide surveillance trial that was conducted in order to evaluate the susceptibility of bacterial isolates to tigecycline in a European country prior to its clinical use. A total of 2,610 Gram-positive and Gram-negative organisms recovered from hospitalized patients were tested. Minimum inhibitory concentrations (MICs) were determined using the microdilution method. All enterococci, staphylococci (including methicillin-resistant Staphylococcus aureus; MRSA), and streptococci tested were tigecycline-susceptible, except one isolate of Staphylococcus haemolyticus. Among the Gram-negative bacteria, 100% of the Escherichia coli isolates (including extended spectrum β-lactamase [ESBL]-producers) were tigecycline-susceptible, while about 10% of the Enterobacter cloacae and Klebsiella pneumoniae isolates were resistant. Based on the results of this surveillance study, tigecycline may represent a suitable option most notably for the empiric treatment of bacterial mixed infections, including in clinical situations in which multi-resistant organisms are suspected.