In vitro activity of tigecycline against patient isolates collected during phase 3 clinical trials for diabetic foot infections

The in vitro activity of tigecycline and comparative antimicrobial agents was evaluated against 1828 primary baseline pathogens isolated from 844 patients enrolled in the phase 3 clinical trials investigating the efficacy of tigecycline in diabetic foot infection (DFI). The trials were global, enrolling patients in 30 countries. Tigecycline was active against the most prevalent pathogens in DFI, including Gram-positive and Gram-negative isolates of both aerobic and anaerobic bacteria with 95% of MICs ≤2 μg/mL for the entire collection. The spectrum of activity of tigecycline included important pathogens for DFI, such as Staphylococcus aureus, Enterococcus faecalis, Streptococcus agalactiae, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, and Bacteroides fragilis. As reported previously, Pseudomonas aeruginosa and several pathogens in the Proteeae group were generally less susceptible to tigecycline by comparison to other Gram-negative pathogens. The excellent in vitro expanded broad-spectrum activity of tigecycline in the clinical isolates confirmed the potential utility of tigecycline for pathogens associated with DFIs.