Table 3

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

E. coli strain A genotypeE. coli strain B genotypeWithout αMGWith 0.5% αMG
CIaP valuebCIP value
λattB::tetWT1.08 ± 0.06NS1.0 ± 0.3NS
ΔsgrS λattB::tetWT0.82 ± 0.01NS0.6 ± 0.10.024
sgrS1manXYZ λattB::tetWT0.98 ± 0.21NS0.5 ± 0.040.01
sgrS28ptsG λattB::tetWT0.93 ± 0.08NS0.8 ± 0.07NS
sgrS1manXYZ λattB::tetΔsgrS1.02 ± 0.15NS1.0 ± 0.01NS
sgrS28ptsG λattB::tetΔsgrS0.97 ± 0.12NS3.5 ± 0.30.03
sgrS28ptsG λattB::tetsgrS1manXYZ1.03 ± 0.08NS2.9 ± 0.10.013
  • 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).