Table 1.

Strains and plasmids used in this work

Strain or plasmidRelevant genotype, phenotype, or serotypeSource or reference
Strains
 EDL933Prototypic O157:H7 EHEC strain 42
 E32511/0O157 EHEC strain 62
 E32511/0 Nalr Nalr spontaneous derivative of E32511/0This study
 413.89-1O26:H STEC strain 61
 EDL933 Δpas EDL933 derivative containing an in-frame deletion of the pas geneThis study
 DH5α endA1 recA1 hsdR17 (rK mK +) supE44 thi-1 gyrA96 φ80dlacZΔM15 Δ(lacZYA-argF)U169 50
 INVαF′F′ endA1 recA1 hsdR17 (rK mK +)supE44 thi-1 gyrA96 relA1 φ80lacZΔM15 Δ(lacZYA-argF)U169 deoR λ Invitrogen
 S17-1λpir Tpr Smr recA thi pro hsdRM+ RP4:2-Tc:Mu:Km Tn7 λpir 10
 M15(pREP4)Nals Strs Rifs lac ara gal mtl F recA+uvr + Qiagen
Plasmids
 pQE30Apr; expression vectorQiagen
 pCR2.1Apr Kmr; high-copy-number vector for cloning PCR productsInvitrogen
 pMAK700oriTCmr; thermosensitive positive-selection suicide vector 57
 pKSC1Cmr; pMAK700oriT derivative containing an 875-kb PCR fragment generated with primers ANK36 and ANK39 and encompassing the pas gene with a 960-bp internal deletionThis study
 pKSC2Apr Kmr; pCR2.1 derivative containing a 1,830-bp PCR fragment generated with primers ANK36 and ANK39 and encompassing the pas gene with upstream and downstream regionsThis study
 pANK84Apr Kmr; pCR2.1 derivative containing a PCR fragment generated with primers ANK7191 and AE19 and encompassing the region between eaeA andespB This study
 pQE30-PasEEApr; pQE30 derivative containing a 1,221-bp PCR fragment generated with primers ANK49 and ANK50 and carrying a histidine-tagged Pas fusion proteinThis study