BackgroundCeftaroline, the active metabolite of ceftaroline fosamil, is a cephalosporin developed for treating infections caused by Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), Streptococcus pneumoniae, β-hemolytic streptococci, and some Gram-negative pathogens. This study reports the in vitro activity of ceftaroline against clinically relevant isolates collected in 2016 from the AWARE Surveillance Program.Methods22,752 non-duplicate methicillin-sensitive S. aureus (MSSA), MRSA, S. pneumoniae, β-hemolytic streptococci (S. pyogenes, S. agalactiae, S. dysgalactiae) Haemophilus influenzae, and extended spectrum β-lactamase (ESBL)-negative Enterobacteriaceae were collected from (n/%) Asia/South Pacific (4,215/18.5%), Europe (12,962/57.0%), Latin America (3,384/14.9%), and Middle East/Africa (2,191/9.6%) during 2016. Isolates were from (n/%) complicated intraabdominal (2,149/9.5%), complicated urinary tract (3,029/13.3%), complicated skin and skin structure (8,271/36.4%), blood stream (2,422/10.6%) and lower respiratory tract infections (6,881/30.2%). MIC values were determined by broth microdilution and interpreted using CLSI breakpoints.ResultsCeftaroline activity, based on % susceptibility (%S) and MIC90, is shown in the table. Ceftaroline was active in vitro against both Gram-positive (100% of MSSA, 93.6% of MRSA and 99.7% of S. pneumoniae) and Gram-negative (99.7% of H. influenzae and 91.7% of ESBL-negative Enterobacteriaceae) isolates. Organism (N) % S % I % R MIC 50 MIC 90 MRSA (5,022)93.66.00.50.51MSSA (3,675)100000.250.25 Streptococcus pneumoniae (2,024)99.7--0.30.0080.12β-hemolytic streptococci (1,713)100----0.0080.015 Enterobacteriaceae, ESBL-Negative (9,647)91.73.74.60.120.5 Haemophilus influenzae (671)99.7--0.3≤0.0150.03%S, %I, %R- percent susceptible, intermediate, resistant based on CLSI breakpoints; MIC50, MIC90 in µg/mL.ConclusionBased on these data generated with isolates collected in 2016, ceftaroline exhibited potent in vitro activity against clinically relevant isolates, with >91% of all isolates susceptible at their CLSI breakpoints. Funding: This study was sponsored by AstraZeneca. The AstraZeneca product ceftaroline fosamil was acquired by Pfizer in December 2016.Disclosures J. Iaconis, AstraZeneca: Employee and Shareholder, Salary and Shareholder in AstraZeneca