TABLE 4

MIC distribution of S. anginosus group isolates as determined by agar dilution (9) and CLSI broth microdilution methods using 80% and 100% MIC endpoint criteria

Agent and readaNo. (cumulative percentage) of isolates inhibited at MIC (μg/ml)d:
≤0.0080.0150.030.060.120.250.512
Tedizolidb1 (1.3)5 (8.0)5 (14.7)18 (38.7)41 (93.3)5 (100.0)
Tedizolid 80c1 (1.9)0 (1.9)5 (11.1)26 (59.3)22 (100.0)
Tedizolid 100c1 (1.9)0 (1.9)2 (5.6)12 (27.8)30 (83.3)9 (100.0)
Linezolidb1 (1.3)4 (6.7)14 (25.3)66 (100.0)
Linezolid 80c1 (1.9)7 (14.8)29 (68.5)16 (98.1)1 (100.0)
Linezolid 100c1 (1.9)4 (9.3)10 (27.8)35 (92.6)4 (100.0)
  • a 100, MIC read at first well that showed no growth; 80, MIC read at first well where trailing began, with tiny buttons ignored (per CLSI documents M07-A10 [2015] and M100-S26 [2016]). For purposes of comparison with tedizolid, the linezolid data are presented as MIC values determined at 80% read to exclude a known trailing effect for bacteriostatic agents and at 100% read, i.e., with no consideration of the trailing endpoint.

  • b Data from Chen et al. (9). MIC values were determined by agar dilution. MIC endpoint criteria are unknown.

  • c Data from the present study. A total of 13 isolates of the S. anginosus group from Taiwan were included in the data set. Tedizolid had MIC ranges of 0.03 to 0.12 μg/ml (modal MIC, 0.06 μg/ml) and 0.06 to 0.12 μg/ml (modal MIC, 0.12 μg/ml) when read at 80 and 100% growth inhibition, respectively, against these 13 isolates. Linezolid showed MIC ranges of 0.25 to 1 μg/ml for both readings, with modal MIC values of 0.5 and 1 μg/ml, when read at 80 and 100% growth inhibition, respectively, against the isolates.

  • d Modal MIC results are in boldface.