TABLE 4.

Single-step resistance selection results

StrainSelecting drugSpontaneous mutation frequency to drug resistance atb:
2 × MIC4 × MIC8 × MIC
SA525 (VSSA)Telavancin<4.0 × 10−11<4.0 × 10−11<4.0 × 10−11
Vancomycin<3.3 × 10−11<3.3 × 10−11<3.3 × 10−11
Teicoplanin1.6 × 10−63.8 × 10−8<6.3 × 10−9
Daptomycin<4.0 × 10−11<4.0 × 10−11<4.0 × 10−11
Linezolid<3.7 × 10−11<3.7 × 10−11<3.7 × 10−11
SA547 (VSSA)Telavancin<4.3 × 10−11<4.3 × 10−11<4.3 × 10−11
Vancomycin<1.7 × 10−10<1.7 × 10−10<1.7 × 10−10
Teicoplanin>4.0 × 10−66.7 × 10−8<6.7 × 10−9
Daptomycin<1.9 × 10−10<1.9 × 10−10<1.9 × 10−10
Linezolid<3.8 × 10−11<3.8 × 10−11<3.8 × 10−11
SA262 (VSSA)Telavancin<4.0 × 10−11<4.0 × 10−11<4.0 × 10−11
Vancomycin<1.0 × 10−10<1.0 × 10−10<1.0 × 10−10
Teicoplanin1.0 × 10−51.7 × 10−83.3 × 10−9
Daptomycin<9.1 × 10−11<9.1 × 10−11<9.1 × 10−11
Linezolid<2.5 × 10−9<2.5 × 10−9<2.5 × 10−9
SA248 (VSSA)Telavancin<4.8 × 10−11<4.8 × 10−11<4.8 × 10−11
Vancomycin<2.5 × 10−9<2.5 × 10−9<2.5 × 10−9
Teicoplanin8.6 × 10−9<1.4 × 10−9<1.4 × 10−9
Daptomycin<6.7 × 10−11<6.7 × 10−11<6.7 × 10−11
Linezolid<2.5 × 10−9<2.5 × 10−9<2.5 × 10−9
SA618 (hVISA)Telavancin<4.3 × 10−11<4.3 × 10−11<4.3 × 10−11
Vancomycin>1.0 × 10−81.0 × 10−8<5.0 × 10−10
Teicoplanin1.6 × 10−61.2 × 10−71.6 × 10−8
Daptomycin5.0 × 10−75.0 × 10−85.0 × 10−9
Linezolid<5.3 × 10−11<5.3 × 10−11<5.3 × 10−11
SA873 (hVISA)Telavancin<1.3 × 10−10<1.3 × 10−10<1.3 × 10−10
Vancomycin<1.3 × 10−10<1.3 × 10−10<1.3 × 10−10
Teicoplanin>1.4 × 10−71.4 × 10−7<1.2 × 10−10
Daptomycin6.7 × 10−7<6.7 × 10−11<6.7 × 10−11
Linezolid<1.9 × 10−10<1.9 × 10−10<1.9 × 10−10
SA555 (VISA)Telavancin<1.0 × 10−10<1.0 × 10−10<1.0 × 10−10
Vancomycin<1.6 × 10−10<1.6 × 10−10<1.6 × 10−10
Teicoplanin<7.1 × 10−11<7.1 × 10−11<7.1 × 10−11
Daptomycin<2.0 × 10−10<2.0 × 10−10<2.0 × 10−10
Linezolid<1.8 × 10−10<1.8 × 10−10<1.8 × 10−10
SA1287 (VISA)Telavancin<5.0 × 10−11<5.0 × 10−11<5.0 × 10−11
Vancomycin<4.3 × 10−11<4.3 × 10−11<4.3 × 10−11
Teicoplanin>8.6 × 10−64.3 × 10−7<1.4 × 10−10
Daptomycin<3.3 × 10−11<3.3 × 10−11<3.3 × 10−11
Linezolid<1.3 × 10−10<1.3 × 10−10<1.3 × 10−10
SA1984 (VISA)Telavancin<4.5 × 10−11<4.5 × 10−11<4.5 × 10−11
Vancomycin<4.8 × 10−11<4.8 × 10−11<4.8 × 10−11
Teicoplanin1.3 × 10−65.0 × 10−84.0 × 10−8
Daptomycin<3.3 × 10−11<3.3 × 10−11<3.3 × 10−11
Linezolid<6.3 × 10−11<6.3 × 10−11<6.3 × 10−11
SA770 (VISA)Telavancin<1.1 × 10−10<1.1 × 10−10<1.1 × 10−10
Vancomycin<5.0 × 10−11<5.0 × 10−11<5.0 × 10−11
Teicoplanin<5.0 × 10−11<5.0 × 10−11<5.0 × 10−11
Daptomycin1.0 × 10−61.7 × 10−7<3.3 × 10−11
Linezolid<7.1 × 10−11<7.1 × 10−11<7.1 × 10−11
E. faecalis HMC568 (VSE)aTelavancin<2.9 × 10−10<2.9 × 10−10<2.9 × 10−10
Vancomycin<8.3 × 10−11<8.3 × 10−11<8.3 × 10−11
Teicoplanin<1.4 × 10−10<1.4 × 10−10<1.4 × 10−10
Daptomycin<6.3 × 10−11<6.3 × 10−11<6.3 × 10−11
Linezolid<6.7 × 10−11<6.7 × 10−11<6.7 × 10−11
E. faecium HMC651 (VSE)Telavancin<2.6 × 10−10<2.6 × 10−10<2.6 × 10−10
Vancomycin<1.4 × 10−10<1.4 × 10−10<1.4 × 10−10
Teicoplanin<1.7 × 10−10<1.7 × 10−10<1.7 × 10−10
Daptomycin<6.7 × 10−11<6.7 × 10−11<6.7 × 10−11
Linezolid<5.6 × 10−11<5.6 × 10−11<5.6 × 10−11
  • a VSE, vancomycin-susceptible enterococci.

  • b Calculated as the number of resistant colonies per inoculum.