TABLE 3.

Time-kill curve results for vancomycin and daptomycin tested against bacteremic MRSA strains

IsolateAntimicrobial agentReduction in log10 CFU/ml ata:Activity categoryb
T4T8T24bT48
170AVancomycin0.91.72.02.8Static
Daptomycin4.85.66.3cdCidal
100AVancomycin0.51.11.92.1Static
Daptomycin6.1c6.1c6.1cCidale
13851AVancomycin0.71.12.94.3Statice
Daptomycin4.86.1c6.1cCidal
16546AVancomycin0.30.82.63.6Staticf
Daptomycin3.54.85.7cCidalg
14382AVancomycin0.10.41.73.0Static
Daptomycin2.74.45.6c5.6cCidal
2345AVancomycin0.51.02.43.4Statice
Daptomycin4.06.0c6.0c6.0cCidal
2308AVancomycin0.81.33.04.1Cidal
Daptomycin4.26.0c6.0cCidal
1416AVancomycin0.10.82.83.9Statice
Daptomycin3.44.85.9cCidal
2336AVancomycin0.40.93.25.6cCidal
Daptomycin3.25.8c5.8cCidal
16542AVancomycin0.31.03.85.5cCidal
Daptomycin3.24.15.5cCidal
16160AVancomycin0.51.73.64.2Cidal
Daptomycin2.22.63.86.0cCidal
5642AVancomycin0.50.72.43.7Statice
Daptomycin2.64.04.3Cidalg
561AVancomycin0.30.82.03.6Statice
Daptomycin3.65.7c5.7cCidal
16325AVancomycin(0.1)h0.32.33.2Statice
Daptomycin3.86.0c6.0cCidal
456AVancomycin0.51.33.63.9Cidal
Daptomycin4.55.6c5.6cCidal
424AVancomycin0.41.03.53.5Cidal
Daptomycin3.15.7c4.8Cidal
3811AVancomycin1.01.62.83.9Statice
Daptomycin2.83.74.9Cidal
14854AVancomycin0.81.23.04.2Cidal
Daptomycin4.45.26.0cCidal
ATCC 29213Vancomycin1.21.42.74.6Statice
Daptomycin3.25.9c5.9c5.9cCidal
ATCC 43300Vancomycin0.71.02.83.7Staticf
Daptomycin2.32.94.0Cidalg
ATCC 33591Vancomycin0.51.33.84.5Cidal
Daptomycin4.04.85.7cCidal
  • a Compared to the initial inoculum. The values represent averages of 2×, 4×, and 8× reductions in log10 CFU/ml.

  • b Bactericidal (Cidal) activity was defined as ≥3 log10 reduction in the initial inoculum within 24 h of incubation.

  • c No bacterial growth was detected.

  • d −, incubated for 24 h only.

  • e Bactericidal activity was achieved only at 48 h of incubation.

  • f Bactericidal activity was achieved at 24 h when tested at 4× and/or 8× MIC.

  • g Bacteriostatic activity when tested at 2× MIC.

  • h Value in parentheses represents the increase in the log10 CFU/ml.