TABLE 3.

Characteristics of SFX-selected mutants of M. hominis^a

Group and strain	MIC (μg/ml)					Mutation(s)b in QRDR of:
	NFX	PFX	OFX	CFX	SFX	GyrA	GyrB	ParC	ParE
Parent M. hominis PG21	4	1	0.5	0.5	0.02
First-step mutants
IS1	8	2	2	2	0.5	Ser83→Leu	None	None	None
IS2	4	2	0.5	1	0.1	None	None	None	None
IS3	4	2	1	1	0.5	Ser84→Trp	None	None	None
IS4	4	2	1	1	0.1	Ser84→Trp	None	None	None
Second-step mutants
IIS1	16	4	8	4	4	Ser83→Leu	None	Glu84→Lys	None
IIS2A	8	4	16	16	4	Ser83→Leu	None	Glu84→Lys	None
IIS2B	8	4	16	16	4	Ser83→Leu	None	Glu84→Lys	None
IIS3A	32	4	8	8	4	Ser84→Trp, Ser83→Leu	None	None	None
IIS3B	32	4	8	8	4	Ser84→Trp, Ser83→Leu	None	None	None
IIS3C	8	4	1	2	1	Ser84→Trp, Ser83→Leu	None	Arg73→His	None
IIS4	4	2	1	2	0.2	Ser84→Trp	None	None	None
Third-step mutants
IIIS1A	>128	32	64	64	16	Ser83→Leu	None	Glu84→Lys	None
IIIS1B	>128	64	64	64	16	Ser83→Leu	None	Glu84→Lys	None
IIIS2A	64	8	16	16	16	Ser83→Leu, Ser84→Trp	None	Glu84→Lys	None
IIIS3A1	128	32	32	32	32	Ser84→Trp, Ser83→Leu	None	Glu84→Lys	None
IIIS3A2	128	32	32	32	32	Ser84→Trp, Ser83→Leu	None	Glu84→Lys	None
IIIS3B1	128	32	32	32	16	Ser84→Trp, Ser83→Leu	None	Glu84→Lys	None
IIIS3B2	128	32	32	32	16	Ser84→Trp, Ser83→Leu	None	Glu84→Lys	None
IIIS3B3	128	32	32	32	32	Ser84→Trp, Ser83→Leu	None	Glu84→Lys	None
IIIS4A	16	8	4	4	2	Ser84→Trp, Ser83→Leu	None	None	None
IIIS4B	32	16	4	8	2	Ser84→Trp, Ser83→Leu	None	None	None

^aLaboratory strains IS1 to IIIS4B were derived from parent wild-type strain PG21 by stepwise selection. 

^bM. hominis GyrA and ParC residues are numbered in accordance with the E. coli GyrA and ParC coordinates.