. 2001 Oct;45(10):2755–2764. doi: 10.1128/AAC.45.10.2755-2764.2001

TABLE 5.

Stepwise selection of serial passage mutants with gatifloxacin^e

Strain or mutation^f	MIC (μg/ml) of:						Mutation
Strain or mutation^f	CIP	GAT	AM-1121	NOV	NAL	EB	grlA	grlB	gyrA	gyrB	norA^c
ISP794	0.25	0.064–0.125	0.125–0.25	0.064–0.128	64–128	2–4
GB	1.0	0.5	1.0	0.032	128	4	None	Pro25His	None	None	None
2GB	1.0	0.5	1.0	0.032	128	4	None^a	Pro25His^b	None^a	None^a	None^a
3GB	16	2	8	0.064	64	32–64	None	Pro25His	Glu88Gly^a	None^a	ATCA insertion^d
4GB	32	4–8	16	0.064	64	32	None	Pro25His	Glu88Gly^a	None^a	ATCA insertion^d
5GB	256	8	256	0.128	64	32	Glu84Lys^a	Pro25His^a ^b	Glu88Gly^a	None^a	ATCA insertion^d
6GB1	256	32	256	0.064	64	32	Glu84Lys^a	Pro25His^a ^b	Glu88Gly	None	ATCA insertion^d
6GB2	256	16	256	0.064	64	32	Glu84Lys^a	Pro25His^a ^b	Glu88Gly^a	None^a	ATCA insertion^d
									Gly106Asp^a

QRDR.

Region of mutation.

Promoter region of NorA.

Insertion is between the 99th and 100th bp upstream of the ATG start codon of norA.

Abbreviations: GAT, gatifloxacin, CIP, ciprofloxacin; NOV, novobiocin; NAL, nalidixic acid; EB, ethidium bromide.

ISP794, wild-type; GB, single-step mutant selected with gatifloxacin. Other mutants are derivatives of GB selected serially on increasing concentrations of gatifloxacin.