TABLE 6.

Characterization of mutants from step selections undertaken with wild-type strains

Strain	Selection agenta	Dayb	Mutation(s) identifiedg	MIC (μg/ml)					Doubling time (min)c
				CBR-2092		Rifampin	Ciprod	EtBre
				Broth	Agar
CB190	CBR-2092	NAf	Wild type	0.015	0.008	0.008	0.25	4	38
CB1880	CBR-2092	2	rpoBR484H	0.12	0.03	>250	0.25	4	43
CB1881	CBR-2092	5	rpoBR484HgyrAΔL520	0.5	0.25	>250	0.5	2	41
CB1882	CBR-2092	10	rpoBR484HgyrAΔL520parCR236†	1	0.5	>250	1	2	45
CB1883	CBR-2092	15	rpoBR484HgyrAΔL520, S84LparCR236†	8	1	>250	1	2	47
CB1884	CBR-2092	26	rpoBR484HgyrAΔL520, S84LparCR236,†H103Y	64	4	>250	8	2	65
CB1871	Rifampin	2	rpoBH481Y	0.12	NDh	>250	0.25	8	ND
CB1875	Ciprofloxacin	15	gyrAS84LparCR298K, LNVIKEE461*	0.008	ND	0.016	>128	64	ND
CB1891	ABT-719	15	gyrAS84LparCE84KparEP587S, F638V	0.03	ND	0.008	>64	64	ND

^aStep selections were undertaken in MHII broth medium without P-80 supplementation.

^bThe day on which the indicated mutant strain was purified.

^cThe time necessary for the optical density at 600 nm of a logarithmic culture propagated at 37°C in MHII broth medium to double.

^dCipro, ciprofloxacin.

^eEtBr, ethidium bromide.

^fNA, not applicable.

^g†, duplication; *, insertion.

^hNA, not applicable.