Table 4.

Competition assays to measure the effects of mutations in the three sgrS targets on growth with αMG in LB medium

E. coli strain A genotype	E. coli strain B genotype	Without αMG		With 0.5% αMG
		CIa	P valueb	CI	P value
ΔptsG λattB::tet	WT	0.96 ± 0.05	NS	2.6 ± 0.1	2.0E−5
ΔmanXYZ λattB::tet	WT	1.01 ± 0.1	NS	1.05 ± 0.04	NS
ΔsgrS ΔptsG λattB::tet	ΔsgrS	1.02 ± 0.03	NS	2.26 ± 0.18	0.0025
ΔsgrS ΔmanXYZ λattB::tet	ΔsgrS	0.98 ± 0.04	NS	1.06 ± 0.11	NS
ΔyigL λattB::tet	WT	0.98 ± 0.07	NS	1.02 ± 0.14	NS

^aSee Materials and Methods for detailed procedures. The competition index (CI) is calculated as follows: (log₁₀ strain A output/log₁₀ strain B output)/(log₁₀ strain A input/log₁₀ strain B input). The results presented here are the averages ± standard deviations of three independent experiments.

^bStudent's t test was used to compare the output and inoculum. NS, not significant (P ≥ 0.05).