Table 1. Gene and protein expression of efflux pump components and regulators in SL1344 csrA::aph and MDR S. Typhimurium and their respective csrA mutants.

Gene/protein		SL1344 csrA::aph		SL1344 ramR::aph	SL1344 ΔramR/csrA::aph	SL1344 MDR mutant	SL1344 MDR mutant/csrA::aph
Fold change in gene/protein expression compared to SL1344
	GFP	RT-PCR	Protein	RT-PCR	RT-PCR	RT-PCR	RT-PCR
ramA/RamA	4.2 ± 1.6*	3.8 ± 1.8*	24.5*	3.8 ± 0.2*	4.9 ± 0.2*	3.1 ± 0.1*	4.1 ± 0.3*
acrAB	1.2 ± 0.9	ND	ND	ND	ND	ND	ND
acrA/AcrA	ND	1.02 ± 0.04	0.2*	2.7 ± 0.2*	2.8 ± 0.1*	2.5 ± 0.2*	2.2 ± 0.2*
acrB/AcrB	ND	1.03 ± 0.03	0.2*	3.9 ± 0.2*	3.7 ± 0.3*	3.2 ± 0.2*	3.1 ± 0.3*
marA	ND	3.1 ± 1.4*	ND	ND	ND	ND	ND
soxS	ND	4.1 ± 1.1*	ND	ND	ND	ND	ND
csrA	ND	ND	ND	1.1 ± 0.03		1.03 ± 0.03

GFP expression data were obtained from fluorescence assays performed with the ramA and acrAB GFP transcriptional fusions as described in the ‘Materials and Methods’ section. RT-PCR expression data was obtained by using a real-time quantitative method as described by Blair et al., (17). Protein expression data was obtained by western blotting and fold change expression data relates to data described in Figure 3. Values were calculated from three biological replicates; ±standard deviation, *P < 0.05 by Student's t-test, Increased expression, bold font; decreased expression, italics. ND, not done.