Table 1

MRSA MIC (mg/liter) statistics for vancomycin and daptomycin, 2006 to 2010

Drug and testYearNo. of isolatesMean MIC (95% CI)Modal MICMIC rangeNo. (%) of isolates with MIC > baseline year median MICcMIC50MIC90
Vancomycin
    Etest at time of isolationTotal991.08 (1.01–1.14)10.50–1.530 (29)11.5
2006a
2007a40.94 (0.74–1.14)10.75–1.011
2008491.06 (0.97–1.15)10.50–1.513 (25)11
2009311.04 (0.93–1.05)10.50–1.58 (26)11
2010151.23 (1.03–1.44)1.50.50–1.59 (56)11.5
    Vitek automated testing at time of isolationTotal500.56 (0.51–0.61)0.50.5–1.06 (12)0.51.5
2006b
2007b
2008b50.70 (0.36–1.04)0.50.5–1.00.51
2009300.52 (0.48–0.55)0.50.5–1.01 (3)0.50.5
2010150.60 (0.49–0.71)0.50.5–1.03 (20)0.51
    Etest on frozen isolatesTotal2060.65 (0.62–0.69)0.50.25–2.090 (43)0.51
2006620.64 (0.57–0.70)0.50.25–1.527 (44)0.51
2007480.72 (0.61–0.83)0.50.38–2.021 (44)0.51.5
2008490.65 (0.59–0.71)0.50.25–1.524 (48)0.51
2009310.60 (0.53–0.66)0.50.38–1.012 (39)0.50.75
2010160.63 (0.51–0.74)0.50.38–1.06 (38)0.51
    BMD analysis of frozen isolatesTotal2061.02 (0.97–1.07)10.5–2.048 (23)11.5
2006621.06 (0.97–1.16)10.5–2.015 (24)11.5
2007480.97 (0.87–1.06)0.750.5–1.511 (23)11.5
2008490.97 (0.90–1.05)10.5–1.58 (16)11.5
2009311.12 (0.97–1.27)0.750.5–2.012 (39)11.5
2010160.97 (0.84–1.11)10.5–1.52 (13)11.5
Daptomycin
    Etest at time of isolationTotal930.18 (0.15–0.20)0.1250.06–0.7526 (25)0.1250.25
2006a
2007a40.19 (0.11–0.27)0.190.13–0.250.190.25
2008460.18 (0.15–0.21)0.1250.09–0.7520 (43)0.1250.25
2009280.19 (0.15–0.23)0.1250.06–0.513 (46)0.1250.38
2010150.13 (0.09–0.16)0.0940.06–0.254 (27)0.0940.25
    Etest on frozen isolatesTotal980.14 (0.12–0.15)0.1250.047–0.561 (60)0.1250.19
2006a
2007a40.13 (0.05–0.20)0.0940.094–0.190.1100.19
2008480.15 (0.12–0.17)0.1250.047–0.515 (31)0.1250.25
2009300.14 (0.12–0.15)0.1250.064–0.259 (29)0.1250.19
2010160.10 (0.08–0.12)0.0940.05–0.191 (6)0.0940.125
  • a Etest analysis was not routine before December 2007.

  • b Vitek automated testing was not routine before November 2008.

  • c The baseline year was taken to be the first full year of data (2008 for Etest at time of isolation and Etest on frozen isolates for daptomycin MIC and 2009 for Vitek 2 automated testing).