TABLE 4.

In vitro antibacterial activities of (±)-PNU-286607 (QPT-1), purified enantiomers, and ciprofloxacin against multiple bacterial isolates

Organism (no. of strains)	Agent	MIC (μg/ml)
		Range	50%	90%
S. aureus, methicillin susceptible (20)	PNU-286607	0.5-1	1	1
	(−)-Enantiomer	0.25-0.5	0.5	0.5
	(+)-Enantiomer	>64	>64	>64
	Ciprofloxacin	0.06-0.5	0.125	0.25
S. aureus, methicillin resistant (20)	PNU-286607	1-4	1	2
	(−)-Enantiomer	0.25-1	0.5	0.5
	(+)-Enantiomer	64->64	>64	>64
	Ciprofloxacin	0.06-32	0.25	32
S. aureus, ciprofloxacin resistant (20)	PNU-286607	0.5-2	1	1
	(−)-Enantiomer	0.25-1	0.5	0.5
	(+)-Enantiomer	64->64	64	>64
	Ciprofloxacin	4->64	16	>64
S. pneumoniae, penicillin susceptible, intermediate, or resistant (20)	PNU-286607	2-8	4	8
	(−)-Enantiomer	1-4	2	4
	(+)-Enantiomer	>64	>64	>64
	Ciprofloxacin	0.5-4	1	2
S. pneumoniae, ciprofloxacin resistant (17)	PNU-286607	1-8	4	8
	(−)-Enantiomer	1-4	2	4
	(+)-Enantiomer	>64	>64	>64
	Ciprofloxacin	2->64	32	64