Table 1.

List of E. coli strains and plasmids used in this study.

E. coli stains and plasmids	Description	Source or reference
O157:H7 str. EDL933	Pathogenic strain isolated from Michigan ground beef	Provided by Pr. Charles Dozois (INRS-IAF)
K-12
ΔampC	F-, Δ(araD-araB)567, ΔlacZ4787(::rrnB-3), λ-, rph-1, Δ(rhaD-rhaB)568, ΔampC777::kan, hsdR514	Genetic stock center (Baba et al., 2006)
ΔampG	F-, Δ(araD-araB)567, ΔlacZ4787(::rrnB-3), ΔampG790::kan, λ-, rph-1, Δ(rhaD-rhaB)568, hsdR514	Genetic stock center (Baba et al., 2006)
Plasmid	Sensitive plasmid	Genetic stock center
pKD46	F-, λ-, rph-1, pKD46	(Datsenko and Wanner, 2000)
pTrc99A	trcP vector, lacI promoter, pUCl8 EcoRI-SmaI,	Provided by Pr. Charles Dozois (INRS-IAF)