TABLE 2.

MRSA 11/11-REF2145 and CB5053-CB5054 counts in target tissues with DAP and/or OX treatment in the IE model

Group (no. of animals)aS. aureus density (log10 CFU/g tissue) inb:
VegetationKidneySpleen
Control without treatment
    MRSA 11/11 (8)7.74 ± 0.795.51 ± 0.635.28 ± 0.56
    MRSA REF2145 (8)8.84 ± 0.566.29 ± 0.676.15 ± 0.65
    CB5053 (6)7.74 ± 0.805.98 ± 0.985.84 ± 0.53
    CB5054 (6)8.76 ± 0.186.63 ± 0.755.95 ± 0.65
Treatment
    MRSA 11/11 (12 mg/kg DAP i.v. once daily) (7)1.58 ± 0.590.53 ± 0.280.60 ± 0.16
    MRSA REF2145 (12 mg/kg DAP i.v. once daily) (7)7.93 ± 1.12*6.74 ± 0.71*5.52 ± 1.23*
    MRSA 11/11 (200 mg/kg OX i.m. t.i.d.) (8)5.96 ± 2.233.99 ± 1.434.07 ± 1.17
    MRSA REF2145 (200 mg/kg OX i.m. t.i.d.) (8)7.21 ± 1.395.09 ± 1.994.79 ± 1.51
    MRSA REF2145 (DAP-OX) (8)4.20 ± 1.61**2.90 ± 1.50**3.12 ± 0.81**
    CB5053 (12 mg/kg DAP i.v. once daily) (6)1.71 ± 0.960.95 ± 0.601.07 ± 0.92
    CB5054 (12 mg/kg DAP i.v. once daily) (6)8.34 ± 0.83*6.32 ± 1.31*5.78 ± 1.29*
    CB5053 (200 mg/kg OX i.m. t.i.d.) (7)6.18 ± 1.744.01 ± 1.823.88 ± 1.19
    CB5054 (200 mg/kg OX i.m. t.i.d.) (6)8.96 ± 0.446.35 ± 1.025.68 ± 0.80
    CB5054 (DAP-OX) (10)5.70 ± 1.98**3.88 ± 1.25**3.99 ± 0.95**
  • a 12 mg/kg DAP intravenously (i.v.) once daily is equivalent to a dose of 6 mg/kg once daily in humans (7).

  • b *, P value of <0.001 relative to the value for DAPs MRSA 11/11 or CB5053 with DAP treatment; **, P value of <0.05 relative to the value for REF2145 or CB5054 with OX-only or DAP-only treatment.