413In Vitro Activity of Tigecycline against Commonly-Isolated Pathogens of Skin and Skin Structure Infections in the United States – TEST 2011-2013

Background. Tigecycline has been approved for the treatment of complicated skin and skin structure infections (SSTIs) in the United States (US) since 2005. Since introduction, tigecycline has shown little development of resistance to common pathogens of SSTIs, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycinresistant Enterococci (VRE) and extended-spectrum β-lactamase (ESBL) –producing Enterobacteriaceae. The Tigecycline Evaluation Surveillance Trial (TEST) has been monitoring the activity of tigecycline and comparators against multiple pathogens collected worldwide since 2004. This study reports on the activity of tigecycline against recent clinical isolates from SSTIs in the US. Methods. A total of 4,229 clinical isolates from SSTI were collected and identified in 124 cumulative sites in the US in 2011-2013. MICs were determined as specified by CLSI at each site using prepared broth microdilution panels and interpreted according to CLSI guidelines. Susceptibility of tigecycline was interpreted using FDA breakpoints. Results. The ESBL rates for Escherichia coli and Klebsiella pneumoniae were 6.2% and 11.6%, respectively. 58.2% of S. aureus were methicillin-resistant. Summary MIC data (μg/ml) and %S for tigecycline vs select isolates are shown in the table.