Activity of tigecycline and five comparators against recent Gram-positive anaerobes in Europe the Tigecycline European Surveillance Trial

Abstract number: P1604

Hackel M., Bouchillon S., Johnson B., Hoban D., Renteria M., Johnson J., Badal R., Hawser S., Dowzicky M.

Objectives: Tigecycline is a novel antimicrobial with expanded broad-spectrum activity from a new class of compounds, the glycylcyclines. Tigecycline was developed to provide activity against tetracycline and multi-drug-resistant Gram-positive pathogens and has demonstrated significant broad-spectrum activity against aerobic and anaerobic Gram-positive and Gram-negative microorganisms. In this study we evaluated tigecycline and five comparator compounds against European Gram-positive anaerobic isolates.

Methods: 454 Gram-positive anaerobic pathogens were collected and identified from 18 sites in 6 countries in Europe. MICs of tigecycline and five comparators were determined per EUCAST guidelines using agar dilution.

Results: European Gram-positive pathogens tested against tigecycline and comparators are shown in the table.

Conclusions: Tigecycline showed excellent in vitro activity against Gram-positive anaerobic microorganisms isolated from European hospitals. MIC50 values for tigecycline against all isolates tested were <0.06 mcg/mL, while MIC90 values were <0.5 mcg/mL. Using the FDA breakpoint of <4 mcg/mL, 100% of the isolates were susceptible to tigecycline, including difficult to treat Clostridium difficile.