Ceftaroline potency among 9 US Census regions: report from the 2010 AWARE Program.

Ceftaroline is a new antibacterial agent that is active against the major bacterial pathogens found in acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. The 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) Surveillance Program in the United States collected a total of 8434 bacterial isolates from 65 US medical centers across 9 US regions. The isolates were cultured and tested for susceptibility to ceftaroline and comparator agents by reference minimum inhibitory concentration (MIC) methods. An analysis by US Census Bureau region demonstrated that Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), and coagulase-negative staphylococci (CoNS), including methicillin-resistant CoNS, were particularly susceptible to ceftaroline (MIC(90), 1 and 0.5 µg/mL respectively). The MRSA rate was 50.0% overall, which varied from a low of 44.6% in the South Atlantic region to a high of 53.1% in the Mountain region. Susceptibility among MRSA for ceftaroline ranged from 96.7% in the West South Central region to 100% in the West North Central region. All MRSA isolates were inhibited at a ceftaroline MIC of ≤ 2 μg/mL, and 98.4% were inhibited at a ceftaroline MIC of ≤ 1 μg/mL. In general, regional differences in activity among staphylococci, streptococci, Haemophilus spp., and Moraxella catarrhalis were minimal due to the high potency of ceftaroline. Greater differences in activity were observed among the Enterobacteriaceae due to the greater diversity of organism types and resistance mechanisms, including those producing extended-spectrum β-lactamase enzymes.