Table 1 Bacterial strains and plasmids used in this study

APEC O1

O1:K1:H7; fyuA, sitA, chuA, irp2, iroN, ireA, tsh, iucD, fimC, iss, ompA, vat, traT; contains four plasmids, including pAPEC-O1-ColBM

[14]

BJ502

E. coli K12, ΔtktA

[15]

DH5α

E. coli K12

APEC O1-M _tkt1

APEC O1 derivative, Δtkt1

this study

APEC O1-M _tktA

APEC O1 derivative, ΔtktA

this study

S17λpir

recA thi pro hsdR^- M⁺ RP4::2-Tc::Mu::Km Tn7 lysogenized with λpir phage

[12]

S17pGP tkt1

S17λpir with plasmid pGP704 tkt1

this study

APEC O1-C _tkt1

APEC O1 M _tkt1 with plasmid pGP tkt1 inserted into bacterial chromosome

this study

APEC O1-P1

APEC O1 M _tkt1 with plasmid pBAD tkt1

this study

BJ502-P1

BJ502 with plasmid pBAD24

this study

BJ502-P2

BJ502 with plasmid pBAD tkt1

this study

BJ502-P3

BJ502 with plasmid pBAD tktA

this study

APEC collection

452 APEC strains isolated from lesions of birds clinically diagnosed with colibacillosis

[17]

Avian fecal E. coli

106 avian fecal E. coli strains were isolated from the feces of apparently healthy birds

[17]

UPEC collection

200 uropathogenic E. coli strains from from MeritCare Medical Center in Fargo, North Dakota

[18]

NMEC collection

91 human neonatal meningitis-causing E. coli strains from the cerebrospinal fluid of newborns in the Netherlands, isolated from 1989 through 1997 and from Dr. K. S. Kim at John Hopkins.

[19]

Plasmids

pGP704

Ap^r, suicide plasmid

[20]

pBAD24

Ap^r, expression plasmid with arabinose-inducible promoter

[21]

pKD46

Ap^r; expresses λ red recombinase

[22]

pKD3

cat gene, template plasmid

[22]

pGP tkt1

pGP704 derivative harboring tkt1 gene

this study

pBAD tkt1

pBAD24 derivative, tkt1 gene under the control of P_BAD

this study

pBAD tktA

pBAD24 derivative, tktA gene under the control of P_BAD

this study