Table 4.

Results of serial passaging studies

StrainaAntibioticMIC (μg/ml)MIC increase (fold)
InitialAfter 15 passages
S. aureus ATCC 19636 (MSSA)MX-2401188
Daptomycin0.524
Vancomycin122
Fusidic acid0.250.52
S. aureus ATCC 29213 (MSSA)MX-24012168
Daptomycin122
VancomycinNAbNANA
Fusidic acidNANANA
S. aureus ATCC 43300 (MRSA)MX-2401188
Daptomycin0.25416
Vancomycin0.524
Fusidic acid0.251664
E. faecium ATCC 51559 (VRE)MX-2401284
Daptomycin0.548
Vancomycin>32>32NA
Fusidic acid4>32>8
E. faecalis ATCC 29212 (VSE)MX-2401c416–324–8
Daptomycinc1–482–8
Vancomycin242
Fusidic acid4>32>8
  • a MRSA, methicillin-resistant S. aureus; MSSA, methicillin-sensitive S. aureus; VRE, vancomycin-resistant enterococci; VSE, vancomycin-sensitive enterococci.

  • b NA, not available.

  • c Results of two experiments are shown.