TABLE 1.

In vivo efficacy of i.v.-administered AC98-6446 and vancomycin against gram-positive pathogens in a murine acute lethal infection model

Compoundc	ED50 in mg/kg (95% confidence limitsa)
	S. aureus (MSSA)	S. aureus (MRSA)	E. faecalis (VRE)	S. pneumoniae (Penrb)	S. pneumoniae (Pensb)
AC98-6446	0.08 (0.07-0.11)	0.27 (0.21-0.34)	0.39 (0.32-0.48)	0.05 (0.04-0.07)	0.07 (0.05-0.09)
Vancomycin	0.69 (0.51-0.97)	2.89 (1.87-7.0)	20 (10.8-44.3)	0.4 (0.31-0.52)	1.55 (1.27-1.89)
LD50d	1.3 × 105	1.1 × 106	1.6 × 106	1.0 × 101	1.8 × 101

^aSeven-day survival ratio from three separate tests, pooled for estimation of ED₅₀ and 95% upper and lower confidence limits by a computerized program for joint probit analysis.

^bPen^r, penicillin-resistant ATCC1894; Pen^s, penicillin-susceptible ATCC6301.

^cAC98-6446 MIC (micrograms per milliliter) for S. aureus (MSSA), 0.03; S. aureus (MRSA), 0.015; E. faecalis, 0.06; S. pneumoniae (Pen^r), <0.008; S. pneumoniae (Pen^s), <0.008. Vancomycin MIC for S. aureus (MSSA), 1; S. aureus (MRSA), 0.5; E. faecalis, >8; S. pneumoniae (Pen^r), <0.5; S. pneumoniae (Pen^s), 0.25.

^dLD₅₀, 50% lethal dose.