TABLE 3.

Mean changes in bacterial viability relative to inoculum of the tested VREfm isolates exposed to daptomycin and oritavancin in the in vitro PK/PD model

Time (h)	Mean decrease in bacterial viability relative to starting inoculum (log CFU/ml ± SD) fora:
	VREfm ATCC 51559		VREfm B7181440		VREfm B7231527
	Daptomycinb	Oritavancin	Daptomycin	Oritavancin	Daptomycin	Oritavancin
1	−1.7 ± 0.2	−0.3 ± 0.2c	−3.6 ± 0.4	−0.5 ± 0.3c	−2.3 ± 0.8	−0.3 ± 0.1c
3	−2.4 ± 0.1	−0.9 ± 0.2c	−4.0 ± 0.2	−1.2 ± 0.3c	−2.8 ± 0.4	−0.8 ± 0.1c
5	−3.2 ± 0.4	−1.5 ± 0.2c	−4.0 ± 0.1	−1.6 ± 0.4c	−3.4 ± 0.5	−1.2 ± 0.2c
7	−3.5 ± 0.1	−1.7 ± 0.5c	−4.2 ± 0.3	−1.7 ± 0.1c	−3.3 ± 0.1	−1.7 ± 0.2c
24	−3.7 ± 0.1	−3.8 ± 0.2	−4.2 ± 0.1	−4.2 ± 0.2	−3.8 ± 0.1	−3.8 ± 0.2
48	−3.7 ± 0.1	−3.9 ± 0.2	−2.8 ± 1.2	−4.2 ± 0.2	−3.0 ± 1.5	−4.0 ± 0.1
72	−3.7 ± 0.1	−3.9 ± 0.2	−0.7 ± 1.5	−4.2 ± 0.2c	0.1 ± 1.2	−4.0 ± 0.1c

^aMean ± SD values shown are from two independent experiments done in duplicate (n = 4).

^bThe calculations of mean decrease in bacterial viability for the daptomycin exposures excluded both that of the single replicate of ATCC 51559 in which reduced susceptibility to daptomycin was observed and that of the single replicate of B7231527 in which no regrowth occurred.

^cDecrease in log CFU/ml is significantly different (P < 0.05, t test) from the corresponding value obtained for daptomycin at the same exposure time.