Table 1.

Strains and plasmids used in this work

Strain or plasmidRelevant genotype, phenotype, or serotypeSource or reference
Strains
 EDL933Prototypic O157:H7 EHEC strain42
 E32511/0O157 EHEC strain62
 E32511/0 NalrNalr spontaneous derivative of E32511/0This study
 413.89-1O26:H STEC strain61
 EDL933 ΔpasEDL933 derivative containing an in-frame deletion of the pas geneThis study
 DH5αendA1 recA1 hsdR17 (rKmK+) supE44 thi-1 gyrA96 φ80dlacZΔM15 Δ(lacZYA-argF)U16950
 INVαF′F′ endA1 recA1 hsdR17 (rK mK+)supE44 thi-1 gyrA96 relA1 φ80lacZΔM15 Δ(lacZYA-argF)U169 deoR λInvitrogen
 S17-1λpirTpr SmrrecA thi pro hsdRM+ RP4:2-Tc:Mu:Km Tn7 λpir10
 M15(pREP4)Nals Strs Rifslac ara gal mtl FrecA+uvr+Qiagen
Plasmids
 pQE30Apr; expression vectorQiagen
 pCR2.1Apr Kmr; high-copy-number vector for cloning PCR productsInvitrogen
 pMAK700oriTCmr; thermosensitive positive-selection suicide vector57
 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 andespBThis 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