Table 1.

Strains and plasmids used in this work

Strain or plasmidRelevant genotype or serotypeReference or source
Strains
 EDL933Prototypic O157:H7 EHEC strain 27
E32511/0O157 EHEC strain 37
E32511/0 Nalr Nalr, spontaneous derivative ofE32511/0This study
 DH5α endA1 recA1 hsdR17(rK mK +) supE44 thi-1 gyrA96 φ80d lacZΔM15 Δ(lacZYA-argF) U169 d 33
 INVαF′F′endA1 recA1 hsdR17 (rK mK +) supE44 thi-1 gyrA96 relA1 φ80 lacZΔM15 Δ(lacZYA-argF) U169deoR λ Invitrogen
 S17-1 (λpir)Tpr Smr recA thi pro, hsdR mutant, M +RP4:2-Tc:Mu:Km Tn7 λpir 7
Plasmids
 pCR 2.1Apr Kmr, high-copy-number vector for cloning PCR productsInvitrogen
 pMAK700oriTCmr, thermosensitive positive-selection suicide vector 35
 pANK1Cmr Kmr, pMAK700oriT derivative with a multiple cloning site and an aph-A3 cassette in theHindIII siteThis study
 pANK84Apr Kmr, pCR 2.1 derivative containing the PCR fragment generated with primers ANK7191 and AE19, which encompass the region between eaeA (position 1891) andespB (position 7544)This study
 pAKSK78Derivative of pANK84 encompassing the region betweeneaeA (position 1891) and the start codon of espD(position 3334)This study
 pANK155CmrKmr, pANK1 derivative with a ΔespD EDL933 fragmentThis study