Update on antimicrobial susceptibility trends among Streptococcus pneumoniae in the United States: report of ceftaroline activity from the SENTRY Antimicrobial Surveillance Program (1998-2011).

A 14-year longitudinal survey of Streptococcus pneumoniae (18,911) strains by the SENTRY Antimicrobial Surveillance Program shows significant increases in resistance to amoxicillin/clavulanate (18.9%), penicillin at a MIC of ≥ 4 μg/mL (14.8%), and ceftriaxone (11.7%) among 2011 isolates. Fluoroquinolones (levofloxacin; 98.8% susceptible) and ceftaroline (99.1-100.0% susceptible depending on breakpoint criteria) exhibited high levels of potency, as did linezolid, tigecycline, and vancomycin (100.0%). In summary, resistance rates to several antimicrobials continue to rise after introductions of both pneumococcal conjugate vaccines, as noted from these results for 1998 through 2011.