Table 1.

Cumulative percentages of inhibition results at each linezolid MIC with testing of six different groups of Gram-positive cocci isolated from all U.S. Census regions (LEADER Program, 2009; 6,414 strains)

Organism group (no. tested)Cumulative % inhibited at linezolid MIC (μg/ml) of:
≤0.120.250.51248>8
Viridans group streptococci (264)1.12.734.597.7100.0
S. pneumoniae (659)0.63.843.496.5100.0
Beta-hemolytic streptococci (401)0.50.511.299.5100.0
CoNS (816)0.11.437.194.498.398.598.9100.0a
Enterococci (1,017)0.00.14.053.498.999.299.6b100.0b
S. aureus (3,257)0.10.20.941.599.899.9>99.9c100.0c
  • a Nine strains from eight states (all S. epidermidis, and eight strains were methicillin resistant).

  • b Eight strains from 5 states, all E. faecium (four strains with MICs of 8 μg/ml and four strains with MICs of >8 μg/ml).

  • c Five strains from 5 states (three strains with MICs of 8 μg/ml and two strains with MICs of >8 μg/ml); all were MRSA.