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 genotypeE. coli strain B genotypeWithout αMGWith 0.5% αMG
CIaP valuebCIP value
ΔptsG λattB::tetWT0.96 ± 0.05NS2.6 ± 0.12.0E−5
ΔmanXYZ λattB::tetWT1.01 ± 0.1NS1.05 ± 0.04NS
ΔsgrS ΔptsG λattB::tetΔsgrS1.02 ± 0.03NS2.26 ± 0.180.0025
ΔsgrS ΔmanXYZ λattB::tetΔsgrS0.98 ± 0.04NS1.06 ± 0.11NS
ΔyigL λattB::tetWT0.98 ± 0.07NS1.02 ± 0.14NS
  • a See 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.

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