TABLE 1.

S. enterica serovar Typhimurium DT104 strains studied

Strain	Geographic origina	SG11	Quinolone MIC (μg/ml)b					MIC of other drugs (μg/ml)			Substitution in gyrA QRDR	WBc AcrA
			NAL	FLU	ENR	MAR	CIP	CHL	FLF	TET
BN10055	F	+	>1,024 (16)	64 (2)	4 (0.125)	2 (0.25)	2 (0.125)	256 (64)	128 (4)	128 (64)	Ser83Tyr	+++
BN10055acrB::kan		+	64	2	0.25	0.25	0.060	16	4	16	Ser83Tyr	NDe
BN10055ΔtolC::kan		+	32	1	0.060	0.125	0.060	16	4	8	Ser83Tyr	ND
543SA98	B	+	1,024 (16)	32 (1)	2 (0.125)	2 (0.25)	1 (0.125)	256 (64)	128 (16)	128 (64)	Ser83Phe	+++
543SA98acrB::kan		+	32	1	0.25	0.25	0.060	16	8	16	Ser83Phe	ND
543SA98ΔtolC::kan		+	16	1	0.125	0.125	0.060	16	8	8	Ser83Phe	ND
BN9945	F	+	512 (16)	32 (1)	1 (0.125)	1 (0.25)	0.5 (0.125)	256 (64)	128 (16)	128 (64)	—f	++
BN9945acrB::kan		+	32	1	0.25	0.125	0.060	16	8	8	—	ND
BN9945ΔtolC::kan		+	16	1	0.060	0.125	0.060	16	8	8	—	ND
BN9181	F	+	4 (0.5)	0.5 (0.03)	0.125 (0.008)	0.060 (0.030)	0.030 (0.015)	256 (64)	32 (2)	64 (32)	—	+
BN9181acrB::kan		+	0.5	0.060	0.008	0.030	0.004	16	2	16	—	ND
BN9181ΔtolC::kan		+	0.5	0.060	0.008	0.008	0.002	16	2	8	—	ND
Control strains
S/921495	S	−	4 (0.5)	0.5 (0.03)	0.125 (0.008)	0.060 (0.008)	0.030 (0.008)	8 (0.5)	8 (1)	2 (0.5)	—	+
S/921495acrB::kan		−	0.5	0.060	0.008	0.008	0.004	0.5	1	0.5	—	ND
S/921495ΔtolC::kan		−	0.5	0.060	0.008	0.008	0.004	1	1	0.5	—	ND
ST-1d	C	+	4 (0.5)	0.5 (0.03)	0.125 (0.008)	0.060 (0.008)	0.030 (0.004)	256 (64)	64 (4)	128 (32)	—	+
ST-1acrB::kan		+	0.5	0.060	0.008	0.008	0.004	16	4	16	—	ND
ST1ΔtolC::kan		+	0.5	0.060	0.008	0.008	0.004	16	4	8	—	ND

^aF, France; B, Belgium; S, Scotland; C, Canada.

^bValues in parentheses are MICs in the presence of the efflux pump inhibitor PAβN at 80 μg/ml.

^cWB, Western blotting with an anti-AcrA polyclonal antibody.

^dST-1 corresponds to strain S/921495 complemented with SGI1.

^eND, not determined.

^f—, no substitution.