TABLE 2.

Fluoroquinolone growth inhibition of S. pneumoniae strain 7785 and drug-stimulated DNA cleavage efficiencies of DNA gyrase and topoisomerase IV

Drug	MIC (μg/ml) for strain 7785	CC25 (μM) for DNA breakagea
		Gyrase	Topoisomerase IV
Ciprofloxacin	1–2	80	2.5
Gemifloxacin	0.06	5	0.1

^aCC₂₅, concentration of drug that converts 25% of the substrate DNA to the linear form in the presence of gyrase or topoisomerase IV.